WO2013017763A1 - Photobioreactor provided with a selective thin-film multilayer - Google Patents

Photobioreactor provided with a selective thin-film multilayer Download PDF

Info

Publication number
WO2013017763A1
WO2013017763A1 PCT/FR2012/051655 FR2012051655W WO2013017763A1 WO 2013017763 A1 WO2013017763 A1 WO 2013017763A1 FR 2012051655 W FR2012051655 W FR 2012051655W WO 2013017763 A1 WO2013017763 A1 WO 2013017763A1
Authority
WO
WIPO (PCT)
Prior art keywords
glazing
layers
substrate
photobioreactor
stack
Prior art date
Application number
PCT/FR2012/051655
Other languages
French (fr)
Inventor
Catherine Bianchi
Stéphane LAURENT
Original Assignee
Saint-Gobain Glass France
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Saint-Gobain Glass France filed Critical Saint-Gobain Glass France
Publication of WO2013017763A1 publication Critical patent/WO2013017763A1/en

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C12BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12MAPPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
    • C12M21/00Bioreactors or fermenters specially adapted for specific uses
    • C12M21/02Photobioreactors
    • CCHEMISTRY; METALLURGY
    • C12BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12MAPPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
    • C12M23/00Constructional details, e.g. recesses, hinges
    • C12M23/22Transparent or translucent parts
    • CCHEMISTRY; METALLURGY
    • C12BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12MAPPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
    • C12M31/00Means for providing, directing, scattering or concentrating light
    • C12M31/08Means for providing, directing, scattering or concentrating light by conducting or reflecting elements located inside the reactor or in its structure
    • CCHEMISTRY; METALLURGY
    • C12BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12MAPPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
    • C12M41/00Means for regulation, monitoring, measurement or control, e.g. flow regulation
    • C12M41/06Means for regulation, monitoring, measurement or control, e.g. flow regulation of illumination
    • C12M41/10Filtering the incident radiation

Definitions

  • the invention relates to the production of a closed photobioreactor comprising an enclosure for culturing biological cells inside said enclosure, said enclosure having a non-opaque front face glazing (that is to say having a transmission luminous throughout the range of visible wavelengths which is non-zero), said front face glazing having a surface in contact with the interior of the enclosure.
  • the invention does not relate to the production of a photobioreactor open on the outside; this type of photobioreactor does not include front-face glazing.
  • the invention also does not concern the production of an opaque bioreactor (that is to say, letting no light pass) and closed; this type of bioreactor does not include non-opaque front face glazing.
  • the invention more particularly relates to a photobioreactor whose enclosure comprises a transparent substrate, in particular a mineral rigid material such as glass, coated with a stack of thin layers comprising several functional layers that can act on the solar radiation and / or radiation long wave infrared.
  • the invention also relates to the use of such substrates coated with a thin film stack comprising a plurality of functional layers for producing a photobioreactor.
  • a photobioreactor The purpose of a photobioreactor is to allow the culturing of biological cells in an immobile medium or circulating inside an enclosure by providing light coming from outside the enclosure, and preferably light solar, through the front face glazing of the enclosure, for cell growth and / or reproduction.
  • a photobioreactor makes it possible to create biomass in a medium using light, through a photo-autotrophic culture.
  • Biomass creates can be used for animal feed, biochemistry, biofuel or C0 2 trap. It is sometimes likened to a greenhouse.
  • tubular photoreactors for which the culture medium is present, mobile or stationary, in a solid cylindrical (column) or hollow, or in vertical, horizontal or inclined coils, and
  • planar photoreactors vertical or inclined with respect to the horizontal, for which the medium is cultured, mobile or immobile, between two flat substrates, a rear-face substrate which is generally opaque and a front-face substrate not opaque.
  • Inclined planar photobioreactors are known, for example, from International Patent Applications Nos. WO 2011/034567 and WO 2011/039354.
  • the biological cell culture chamber of a closed photobioreactor has a non-opaque front face glazing which allows the passage of light to the culture medium.
  • the culture chamber is essentially formed of the front-face glazing since there is no back-face substrate and this front-face glazing is curved.
  • the front face glazing has a surface in contact with the interior of the enclosure which can be in direct contact with the culture medium, but which may also not be in direct contact with the culture medium. if a gaseous atmosphere is formed between the culture medium and the surface of the front face glazing which is in contact with the interior of the enclosure.
  • glazing used here is to be taken in its most general sense, as a flat or curved wall consisting of one or more sheets, each of mineral material such as glass, or organic material such as a plastic material. This glazing is located between the light source (for example the sun) and the culture medium.
  • the front-face glazing of a photobioreactor is relatively transparent in the sense that, even though it does not exhibit a 100% light transmission over the entire wavelength range of the visible range (which is in practice impossible), it still has a high light transmission (more than 50%) over at least part of the wavelength range of the visible range.
  • the infrared range (in particular the wavelength range of 780 nm to 2500 nm) is thus harmful because it generates a heating of the medium without benefit for the medium, which requires to provide special means for cooling the medium or in any case to contain its temperature in a range beneficial to the culture of the cells; the ultraviolet range is also sometimes harmful to the culture of certain biological cells.
  • the object of the invention is thus to make it possible to produce a closed photobioreactor whose front face glazing which is located between the light source and the culture medium, on the one hand allows the passage of light radiation favorable to the culture (c that is to say, corresponding to the spectral range favorable to the medium), in order to achieve a high efficiency and on the other hand reflects infrared radiation harmful to the culture.
  • the color of the front-face substrate can cause absorption of a portion of the infrared radiation; this Infrared radiation can not reach the culture medium; however, such an absorption is harmful because it necessarily generates a warming of the front face substrate which hinders the culture because this heat is transmitted to the medium, whereas a reflection of the infrared radiation does not cause warming of the front face substrate and thus avoids a heat transmission in the middle.
  • the invention thus has, in its broadest sense, a photobioreactor according to claim 1.
  • This photobioreactor comprises an enclosure for culturing cells inside this chamber, this chamber having a non-opaque front face glazing, said front face glazing having an inner surface in contact with the interior of the enclosure, the photobioreactor being remarkable in that said front-face glazing comprises a substrate which is provided with a stack of thin layers comprising an alternation of "n" metal functional layers, in particular functional layers based on silver or metal alloy containing silver, and "(n + 1)" antireflection coatings, with n integer> 3, each antireflection coating having at least one antireflection layer, so that each functional layer is disposed between two antireflection coatings.
  • stacks of thin layers or coatings without a metallic functional layer and which prevent the passage of near-infrared radiation there are certainly stacks of thin layers or coatings without a metallic functional layer and which prevent the passage of near-infrared radiation; however, these stacks of thin layers or coatings on the one hand generally have a transmission in the spectral range favorable to the medium which is not very high (of the order of 60% or less) and on the other hand absorb for the essential near infrared; using such stacks of thin layers or coatings would not achieve a high efficiency for culturing biological cells due to transmission losses in the spectral range favorable to the environment and would necessarily cause a warming of the front face glazing of the photobioreactor of the made of the absorption by the glazing of front face in the near infrared.
  • a stack of thin layers with at least three metallic functional layers has the double advantage:
  • the presence of such a stack makes it possible to reach a high efficiency because of the low transmission losses in the medium-favorable spectral range, makes it possible to prevent infrared from reaching the culture medium, without causing an increase.
  • the temperature of the inner surface of the front-face glazing the one that is in contact with the interior of the enclosure.
  • stack of thin layers designates all the thin layers present on the face of the substrate in question. This presence is observed by standard techniques of scanning electron microscopy (SEM), transmission electron microscopy (TEM), or secondary ion mass spectrometry (SIMS).
  • SEM scanning electron microscopy
  • TEM transmission electron microscopy
  • SIMS secondary ion mass spectrometry
  • the stack of thin layers with at least three metal functional layers is disposed on a face of the substrate other than the inner surface of the glazing which is in contact with the inside of the enclosure; thus, the reflection of near-infrared radiation is even more effective.
  • each metallic functional layer is disposed between two antireflection coatings each comprising at least one (and in general several) antireflection layer (s) which is (are each) of a material dielectric nitride type and in particular silicon nitride or aluminum and / or oxide type.
  • antireflection layer s
  • the purpose of these coatings which frame each functional layer is to "antireflect" this functional layer; the antireflection layers are not, by nature, metal layers.
  • a very thin blocking coating is however sometimes interposed between one or each antireflection coating and an adjacent functional layer: a blocking coating disposed under the functional layer in the direction of the substrate and / or a blocking coating disposed on the functional layer to the opposite of the substrate and which protects this layer from possible degradation during the deposition of the upper antireflection coating and during a possible heat treatment at high temperature, of the bending and / or quenching type.
  • This coating may have a metallic or oxidized nature and in particular a sub-oxidized nature; however, its effect on radiation transmission or reflection characteristics is generally neglected.
  • the layer thicknesses discussed herein are physical or actual thicknesses (and not optical thicknesses).
  • the antireflection layer which is at least included in each antireflection coating, as defined above, has an optical index measured, as usual, at 550 nm between 1.8 and 2.5 including these values, or, preferably, between 1, 9 and 2,3 including these values, ie an optical index that can be considered high.
  • the last layer of the first antireflection coating underlying the first functional layer starting from the substrate is a crystallized oxide (ie: non-amorphous) wetting layer, in particular based on zinc oxide.
  • this first antireflection coating underlying the first functional layer may further comprising a smoothing layer, a non-crystallized mixed oxide (ie: amorphous), said smoothing layer being in contact with said overlying fog layer.
  • this wetting layer and this optional smoothing layer belong to an antireflection coating, they are in fact antireflection layers.
  • the thickness of said smoothing layer is preferably about 1/6 th of the thickness of said first antireflection coating and about half the thickness of said first functional layer.
  • each antireflection coating underlying a functional layer is a wetting layer based on crystalline oxide, in particular based on zinc oxide, optionally doped with the aid of minus another element, like aluminum.
  • Each wetting layer is an anti-reflective layer.
  • each antireflection coating which is situated above a functional layer comprises a layer based on silicon nitride Si 3 N 4 or based on aluminum nitride AIN.
  • said antireflection coatings each comprise at least one layer based on silicon nitride Si 3 N 4 or based on aluminum nitride AIN.
  • the silicon nitride Si 3 N 4 and the aluminum nitride AIN may optionally be doped with at least one other element, such as aluminum.
  • These layers based on Si 3 N 4 and / or AIN are in fact antireflection layers.
  • the carrier substrate of the stack of thin layers according to the invention is capable of undergoing heat treatment without damage for the stack of thin layers. It can therefore possibly be curved and / or tempered after the deposition of the stack of thin layers.
  • the carrier substrate of the stack is quenched, it is mechanically very strong.
  • the carrier substrate of the stack when curved, allows for a curved front face for a tubular photobioreactor.
  • each functional layer is preferably between 8 and 20 nm including these values, or even between 10 and 18 in nm including these values, and more preferably between 11 and 15 in nm including these values.
  • the total thickness of the metal functional metallic layers is preferably greater than 30 nm and this total thickness is:
  • this total thickness is between 35 and 50 nm for a thin film stack with three functional metal layers (in particular each based on silver, or even silver),
  • - Or is between 40 and 60 nm for a thin film stack with four functional metal layers (in particular each based on silver or silver).
  • the front-face glazing further comprises at least one stack of thin antireflection layers having no metallic functional layer; this antireflection thin film stack having no metallic functional layer is located on a surface of a substrate other than the surface on which is arranged the thin film stack with several functional metal layers.
  • Such a stack of thin antireflection layers may be disposed on the outer surface or on the inner surface of the front face glazing.
  • Such a stack of thin antireflection layers, and a fortiori two stacks of thin antireflection layers disposed respectively on the outer surface and on the inner surface of the front face glazing allows (tent) to further increase the high transmittance of the glazing in the spectral range. favorable to the environment without degrading the high reflection in the infrared.
  • the front face glazing has an outer surface textured by a plurality of geometric patterns in relief relative to the general plane of said surface, the surface of said patterns each comprising at least two points such that there are two intersecting planes between them each containing one of said two points and meeting the two following conditions:
  • these planes each contain one of the two straight lines perpendicular to said surface and passing through one of said two points.
  • the front-face glazing has a textured outer surface in the manner of what is known from International Patent Applications No. WO 2006/134300, WO 2006/134301 or WO 2010/084290.
  • the present invention thus relates to a carrier substrate of a stack of thin layers according to the invention and possibly forming alone the front face glazing; however, this substrate is preferably associated with at least one other substrate to form a laminated front face glazing, said carrier substrate of the thin film stack being curved and / or tempered.
  • the substrate, or each substrate, of the front-face glazing is preferably clear, but it can also be colored. At least one of the substrates may be colored glass in the mass. The choice of the type of coloration will depend on the desired light transmission values for certain wavelength ranges of the visible range for the front face glazing once its manufacture is complete.
  • the front-face glazing according to the invention may have a laminated structure, in particular associating at least two rigid substrates of the glass type with at least one thermoplastic polymer sheet, in order to present a glass / thin-film / sheet-like structure ( s) polymer / glass.
  • the polymer may especially be based on polyvinyl butyral PVB, ethylene vinyl acetate EVA, PET polyethylene terephthalate, PVC polyvinyl chloride.
  • the front face glazing can then have a structure of the type: glass / stack of thin layers / sheet (s) of polymer / glass, or: glass / polymer sheet (s) / stack of thin layers / sheet (s) polymer / glass.
  • the front face glazing can be curved and / or tempered by being constituted by a single substrate, the one provided with the stack. It is then a glazing called "monolithic". In the case where it is curved, especially in order to constitute a front face glazing of a tubular photoreactor, the stack of thin layers is then on an at least partially non-planar face.
  • At least the carrier substrate of the stack may be curved or tempered glass, this substrate being curvable or tempered before or after the deposition of the stack.
  • PE polystyrene
  • PMMA may lose their transparency over time and the PVC may turn yellowish
  • a laminated structure for which all the components are thus in contact with each other, allows a front face glazing having high energy transmission by conduction; as a result, the heat produced by the medium can be evacuated through the front face glazing by conduction, despite the presence of the stack of thin layers (which is also opposed to the transmission of this heat by radiation). because of its low-emissivity character).
  • a multiple front face glazing that incorporates at least one spacer space, double glazing type or triple glazing, is not advisable because this space will oppose the evacuation of the heat produced by the medium to through conduction front glazing (and the stack of thin layers is also opposed to the transmission of this heat by radiation due to its low-emissivity).
  • the invention furthermore relates to the use, for producing a photobioreactor according to the invention, of a substrate which is provided with a stack of thin layers comprising an alternation of "n" metal functional layers, in particular functional layers based on of silver or metal alloy containing silver, and "(n + 1)" antireflection coatings, with n integer> 3, each antireflection coating comprising at least one antireflection layer, so that each layer functional is arranged between two antireflection coatings.
  • the present invention makes it possible to produce a front-panel glazing having, for the entire solar spectrum:
  • the present invention also allows heat exchange by conduction with the outside.
  • FIG. 1 a vertical sectional view of a photobioreactor according to the invention which is plane and inclined;
  • FIG. 2 a perspective view of a photobioreactor according to the invention which is cylindrical and hollow;
  • FIG. 3 a perspective view of a photobioreactor according to the invention which is cylindrical and solid;
  • each functional layer is not provided with a sub-blocking coating but being provided with an over-blocking coating and the stack being further provided an optional protective coating.
  • FIG. 1 illustrates a photoreactor 1 of the "planes" type, inclined relative to the horizontal, for which the cultivated medium is movable between two flat substrates which are neither horizontal nor vertical.
  • Photobioreactor 1 comprises an enclosure 2 for culturing cells inside I of this chamber.
  • This enclosure 2 comprises a non-opaque front face substrate 3 and a backside substrate 4 which is generally opaque (even if this is not an obligation).
  • the chamber 2 furthermore comprises a low upright 5, a high upright 5 'and lateral uprights (not shown) which provide the hermetic connection to the device, respectively low, high and on the sides between the front face substrate 3 and the backside substrate 4.
  • the photobioreactor 1 also comprises a pumping system (not shown) which sucks the culture medium near the low amount to push it close to the high amount.
  • the culture medium 6 is thus driven from top to bottom, under the effect of gravity, by trickling on the inside face of the rear-face substrate 4, as illustrated by the double arrows.
  • the front face substrate 3 and the back face substrate 4 are arranged parallel to each other.
  • the rear face substrate 4 (and therefore also the face substrate 3) is oriented at an angle ⁇ of the order of 30 ° or 45 ° relative to the horizontal thanks to a frame 7.
  • the front face glazing 3 has an inner surface 30 in contact with the interior I of the enclosure 2 and an outer surface 31 in contact with the environment.
  • a space is provided between the culture medium 6 and the inner surface 30 of the front face glazing 3.
  • FIGS. 2 and 3 illustrate two examples of so-called “tubular" photoreactors, one in FIG. 2 where the medium is cultured, mobile or immobile, in a solid cylindrical column and the other in FIG. 3 where the medium is cultured , mobile or immobile, in a hollow cylindrical.
  • the chamber 2 comprises a non-opaque front face substrate 3 of cylindrical shape.
  • the chamber 2 further comprises a rear face substrate 4 which is opaque or not and which is also of cylindrical shape but with a radius smaller than that of the front face substrate 3.
  • the radii of these two cylinders are preferably concentric so that the space between the two substrates is always the same along the axis of the enclosure.
  • Figures 4 and 5 illustrate two examples of laminated front face glazing structures for photobioreactor.
  • the front face glazing 3 consists of a laminated glazing unit comprising two glass substrates: the substrate 10, on one side of which is deposited the stack of thin layers 1 1, and a second substrate 400.
  • plastic sheet 300 is located between the two glass substrates.
  • the substrate 10 is more outside the enclosure than the second substrate 400 and the stack of thin layers January 1 is located on the face of the substrate 10 which is oriented towards the interlayer plastic sheet 300.
  • the stack of thin layers 1 1 is disposed in face 2, considering, as usual, that the face 1 is the face of the outermost pane and that the faces are numbered in ascending order from the face of the more outside.
  • the inner surface 30 of the front face glazing 3 is thus constituted by the face of the second innermost substrate 400 and the outer surface 31 of the front face glazing 3 is thus constituted by the face of the substrate 10. 'outside.
  • the front face glazing 3 comprises two stacks of thin antireflection layers 12, 13, situated respectively on the outer surface 31 and on the inner surface 30.
  • Each of these antireflection thin film stacks does not have a metallic functional layer. It could be envisaged to provide only a single antireflection thin layer stack, located on the outer surface 31 or on the inner surface 30.
  • FIG. 6 illustrates on the ordinate the absorption coefficient of the microalgae tested, as a function of the wavelength ⁇ (in nanometers) on the abscissa.
  • This curve makes it possible to apprehend the light absorption of microalgae: this absorption is high in the range 400-500 nm, low in the range 500-650 nm, high in the range 650-700 nm, then low beyond. This is a typical profile of micro-algae.
  • FIG. 7 illustrates a stacking structure with three functional layers 40, 80, 120, this structure being deposited on the transparent glass substrate 10.
  • Each functional layer 40, 80, 120 is disposed between two antireflection coatings 20, 60, 100, 140, so that the first functional layer 40 starting from the substrate is disposed between the antireflection coatings 20, 60; the second functional layer 80 is disposed between the antireflection coatings 60, 100 and the third functional layer 120 is disposed between the antireflection coatings 100, 140.
  • These antireflection coatings 20, 60, 100, 140 each comprise at least one dielectric antireflection layer 24, 26, 28; 62, 64, 66, 68; 102, 104, 106, 108; 142, 144.
  • each functional layer 40, 80, 120 may be deposited on a sub-blocking coating (not illustrated) disposed between the underlying antireflection coating and the functional layer, and on the other hand each functional layer may be deposited directly under an over-blocking coating 55, 95, 135 disposed between the functional layer and the antireflection coating overlying this layer.
  • a sub-blocking coating not illustrated
  • each functional layer may be deposited directly under an over-blocking coating 55, 95, 135 disposed between the functional layer and the antireflection coating overlying this layer.
  • front glazing were tested, numbered from 1 to 4 below. These four glazings are laminated glass structures: glass substrate / interlayer sheet PVB / glass substrate.
  • Example 1 is a reference example having the same substrate structure / spacer sheet / substrate, but without stacking thin layers.
  • the stack of thin layers is deposited on a clear soda-lime glass substrate with a thickness of 1.6 mm, distributed by the company SAINT-GOBAIN.
  • the carrier substrate 10 of the stack is the one that is positioned closest to the sun, that is to say that during the tests carried out, there were, in this order: sun / substrate 10 / stack of thin layers 11 (except for example 1) / spacer 300 / substrate 400 / micro-algae, as shown in FIG. 4, with the sun above the outer surface 31 of the front face 3 and the micro-algae under the surface inside 30 of the front face 3.
  • Each antireflection coating 20, 60, 100 underlying a functional layer 40, 80, 120 comprises a final wetting layer 28, 68, 108 based on crystalline zinc oxide, doped with aluminum and which is in contact with of the functional layer 40, 80, 120 deposited just above.
  • Each antireflection coating 20, 60, 100, 140 comprises a layer 24, 64, 104, 144 based on silicon nitride, doped with aluminum. These layers are important for obtaining the oxygen barrier effect during the heat treatment, in order to preserve the metal functional layers of the oxygen attack during a heat treatment.
  • FIG. 7 it can be seen that the stack ends with an optional protective layer 200, which is not present for examples 2 to 4.
  • the deposition conditions of the layers, which have been deposited by sputtering are as follows:
  • each antireflection coating 60, 100, 140 which is located above a functional layer 40, 80, 120 has a silicon nitride layer
  • the stack of Example 4 further has the advantage of being hardenable or bumpable and may undergo an integration operation in a laminated glazing without its optical and thermal properties are modified.
  • Table 3 summarizes for Examples 1 to 4 the main optical characteristics measured for the complete laminated glazing unit integrating the carrier substrate of the stack:
  • the photosynthetic transmission corresponds to the integration of the absorption spectrum of the micro-algae (that of figure 6), the standardized solar spectrum (norm ISO 9050 AM 1, 5) and the transmission of the glazing considered for this spectrum; this corresponds to what the micro-algae "perceive" from the solar spectrum, in the way that the eyes of a human being perceive from this same solar spectrum;
  • the efficiency compared is the efficiency of each of Examples 2 to 4, compared with that of Example 1, that is to say compared to that of a laminated glazing without stacking thin layers;
  • TE is the energy transmission through the glazing, in percentage, measured according to the ISO 9050 AM 1.5 standard, that is to say the fraction of energy transmitted directly through the microalgae glazing;
  • the RE is the energy reflection through the glazing, in percentage, measured according to the ISO 9050 AM 1.5 standard, that is to say the fraction of energy reflected directly by the glazing and which can not reach the microalgae;
  • the TTS corresponds to the abbreviation in English of the expression "Total Transmitted Sun”; it is the sum of the total energy transmission through the glazing, which takes into consideration both the TE and the energy re-emitted by radiation from the glazing towards the inside of the photobioreactor, for an average outside wind of 4 m / s;
  • the TIR corresponds to the transmission of the glazing over the infrared wavelength range of 780 nm to 2500 nm;
  • the RIR corresponds to the reflection of the glazing over the infrared wavelength range of 780 nm to 2500 nm.
  • a photobioreactor in which the front-face glazing comprises a stack of one (eg 1), two (eg 2) or three (eg 3) metallic functional layer (s), therefore, at first sight less effective.
  • Table 3 shows that on the one hand the energetic transmission of Example 4 is better than that of Examples 1 to 3, since it is the smallest and on the other hand that the total energy transmission of the example 4 is better than that of Examples 1 to 3 since it is the smallest, even though the energy transmission of Examples 2 (to a functional layer) and 3 (two functional layers) is substantially identical.
  • Table 3 furthermore shows that the transmission in the infrared is practically zero (less than 10%) for example 4 while it is relatively high for examples 2 and 3 and that the reflection in the infrared is very high. (greater than 60%) for Example 4 whereas it is relatively low and identical for Examples 2 and 3.
  • Example 4 Each can thus see, on the one hand, that the light transmission of Example 4 is almost zero in the near infrared (from 780 nm to 980 nm) whereas it is much lower for Examples 1 to 3 and is zero. for the longer wavelengths and secondly that the light transmission of Example 4 is the one that best meets the expectations for the absorption of microalgae since this light transmission is high in the range 400 -500 nm, lower in the range 500-650 nm, then again raised in the range 650-700 nm, then low beyond.
  • the present invention thus makes it possible to achieve a transmission very close to the ideal light transmission which would be a transmission of 100% in the absorption domain of microalgae and only in this area of absorption of microalgae.
  • the laminated structure of the front-face glazing unit of Example 4 also has the advantage of counteracting the low-emissive effect of the stack of thin layers vis-à-vis the medium by allowing the heat produced by the medium to be removed by conduction through the laminated structure despite the presence of the stack of thin layers.
  • Example 4 the temperature of the medium tested with Example 4 remained almost identical while under the same conditions the temperature of the medium tested with Example 1 was raised to 17 ° C. Moreover, the use of a laminated glazing unit incorporating a plastic interlayer sheet makes it possible to obtain a UV transmission of less than 1%.
  • a stack of four metal functional layers, including four silver-based metal or silver-containing functional layers, and five anti-reflective coatings so that each functional layer is disposed between two anti-reflective coatings will have a transmission. luminous enough close to that of a stack with three functional metal layers such as those of Example 4.

Abstract

The invention relates to a photobioreactor (1) comprising a chamber (2) for culturing cells in the interior (I) of this chamber, this chamber (2) having a non-opaque frontside glazing unit (3), said frontside glazing unit (3) having an interior surface (30) making contact with the interior (I) of the chamber (2), characterized in that said frontside glazing unit (3) comprises a substrate (10) that is provided with a thin-film multilayer (11) comprising an alternation of "n" functional metal films (40, 80, 120), in particular functional films based on silver or a silver-containing metal alloy, and "(n + 1)" antireflection coatings (20, 60, 100, 140), where n is an integer ≥ 3, each antireflection coating comprising at least one antireflection film (24, 64, 104, 144), in such a way that each functional film (40, 80, 120) is placed between two antireflection coatings (20, 60, 100, 140).

Description

PHOTOBIOREACTEUR MUNI D'UN EMPILEMENT DE COUCHES MINCES  PHOTOBIOREACTOR PROVIDED WITH A STACK OF THIN LAYERS
SELECTIF L'invention concerne la réalisation d'un photobioréacteur fermé comportant une enceinte pour la culture de cellules biologiques à l'intérieur de cette enceinte, cette enceinte présentant un vitrage de face avant non opaque (c'est-à-dire présentant une transmission lumineuse dans toute la gamme de longueurs d'ondes du visible qui est non nulle), ledit vitrage de face avant présentant une surface en contact avec l'intérieur de l'enceinte.  The invention relates to the production of a closed photobioreactor comprising an enclosure for culturing biological cells inside said enclosure, said enclosure having a non-opaque front face glazing (that is to say having a transmission luminous throughout the range of visible wavelengths which is non-zero), said front face glazing having a surface in contact with the interior of the enclosure.
L'invention ne concerne pas la réalisation d'un photobioréacteur ouvert sur l'extérieur ; ce type de photobioréacteur ne comporte pas de vitrage de face avant.  The invention does not relate to the production of a photobioreactor open on the outside; this type of photobioreactor does not include front-face glazing.
L'invention ne concerne pas non plus la réalisation d'un bioréacteur opaque (c'est-à-dire ne laissant passer aucune lumière) et fermé ; ce type de bioréacteur ne comporte pas de vitrage de face avant non opaque.  The invention also does not concern the production of an opaque bioreactor (that is to say, letting no light pass) and closed; this type of bioreactor does not include non-opaque front face glazing.
L'invention concerne plus particulièrement un photobioréacteur dont l'enceinte comporte un substrat transparent, notamment en un matériau rigide minéral comme le verre, revêtu d'un empilement de couches minces comprenant plusieurs couches fonctionnelles pouvant agir sur le rayonnement solaire et/ou le rayonnement infrarouge de grande longueur d'onde.  The invention more particularly relates to a photobioreactor whose enclosure comprises a transparent substrate, in particular a mineral rigid material such as glass, coated with a stack of thin layers comprising several functional layers that can act on the solar radiation and / or radiation long wave infrared.
L'invention concerne aussi l'utilisation de tels substrats revêtus d'un empilement de couches minces comprenant plusieurs couches fonctionnelles pour fabriquer un photobioréacteur.  The invention also relates to the use of such substrates coated with a thin film stack comprising a plurality of functional layers for producing a photobioreactor.
Le but d'un photobioréacteur est de permettre la culture de cellules biologiques dans un milieu immobile ou qui circule à l'intérieur d'une enceinte en apportant de la lumière venant de l'extérieur de l'enceinte, et de préférence de la lumière solaire, à travers le vitrage de face avant de l'enceinte, pour la croissance des cellules et / ou leur reproduction.  The purpose of a photobioreactor is to allow the culturing of biological cells in an immobile medium or circulating inside an enclosure by providing light coming from outside the enclosure, and preferably light solar, through the front face glazing of the enclosure, for cell growth and / or reproduction.
Un photobioréacteur permet de créer de la biomasse dans un milieu utilisant la lumière, par une culture photo-autotrophe. La biomasse crée peut servir notamment à l'alimentation animale, à la biochimie, ou encore comme biocarburant ou comme piège de C02. Il est parfois assimilé à une serre. A photobioreactor makes it possible to create biomass in a medium using light, through a photo-autotrophic culture. Biomass creates can be used for animal feed, biochemistry, biofuel or C0 2 trap. It is sometimes likened to a greenhouse.
Les photobioréacteurs fermés connus sont en général classés dans une des deux catégories suivantes :  Known closed photobioreactors are generally classified into one of two categories:
- les photoréacteurs dits « tubulaires », pour lesquels le milieu de culture est présent, mobile ou immobile, dans un cylindrique plein (colonne) ou creux, ou dans des serpentins, verticaux, horizontaux ou inclinés, et  the so-called "tubular" photoreactors, for which the culture medium is present, mobile or stationary, in a solid cylindrical (column) or hollow, or in vertical, horizontal or inclined coils, and
- les photoréacteurs dits « plans », verticaux ou inclinés par rapport à l'horizontale, pour lesquels le milieu est cultivé, mobile ou immobile, entre deux substrats plans, un substrat de face arrière qui est généralement opaque et un substrat de face avant non opaque.  the so-called "planar" photoreactors, vertical or inclined with respect to the horizontal, for which the medium is cultured, mobile or immobile, between two flat substrates, a rear-face substrate which is generally opaque and a front-face substrate not opaque.
Des photobioréacteurs plans inclinés sont connus par exemple des demandes internationales de brevet N° WO 2011 /034567 et WO 2011 /039354.  Inclined planar photobioreactors are known, for example, from International Patent Applications Nos. WO 2011/034567 and WO 2011/039354.
Dans tous les cas, l'enceinte de culture des cellules biologiques d'un photobioréacteur fermé présente un vitrage de face avant non opaque qui permet le passage de la lumière vers le milieu de culture.  In all cases, the biological cell culture chamber of a closed photobioreactor has a non-opaque front face glazing which allows the passage of light to the culture medium.
Dans le cas des photobioréacteurs en colonne ou en serpentin, l'enceinte de culture est formée pour l'essentiel du vitrage de face avant puisqu'il n'y a pas de substrat de face arrière et ce vitrage de face avant est cintré.  In the case of column or serpentine photobioreactors, the culture chamber is essentially formed of the front-face glazing since there is no back-face substrate and this front-face glazing is curved.
Dans tous les cas, le vitrage de face avant présente une surface en contact avec l'intérieur de l'enceinte qui peut être directement en contact avec le milieu de culture, mais qui peut aussi ne pas être directement en contact avec le milieu de culture si une atmosphère gazeuse est ménagée entre le milieu de culture et la surface du vitrage de face avant qui est en contact avec l'intérieur de l'enceinte.  In all cases, the front face glazing has a surface in contact with the interior of the enclosure which can be in direct contact with the culture medium, but which may also not be in direct contact with the culture medium. if a gaseous atmosphere is formed between the culture medium and the surface of the front face glazing which is in contact with the interior of the enclosure.
Le terme « vitrage » utilisé ici est à prendre dans son sens le plus général, comme une paroi plate ou incurvée constituée d'une ou de plusieurs feuilles, chacune en matière minérale comme un verre, ou en matière organique comme une matière plastique. Ce vitrage est situé entre la source lumineuse (par exemple le soleil) et le milieu de culture. Le vitrage de face avant d'un photobioréacteur est relativement transparent dans le sens où, même s'il ne présente pas une transmission lumineuse de 100 % sur la totalité de la plage de longueur d'onde du domaine visible (ce qui est en pratique impossible), il présente toute de même une transmission lumineuse élevée (plus de 50 %) sur au moins une partie de la plage de longueur d'onde du domaine visible. The term "glazing" used here is to be taken in its most general sense, as a flat or curved wall consisting of one or more sheets, each of mineral material such as glass, or organic material such as a plastic material. This glazing is located between the light source (for example the sun) and the culture medium. The front-face glazing of a photobioreactor is relatively transparent in the sense that, even though it does not exhibit a 100% light transmission over the entire wavelength range of the visible range (which is in practice impossible), it still has a high light transmission (more than 50%) over at least part of the wavelength range of the visible range.
Toutefois, certaines plages de longueurs d'onde ne sont pas utiles aux cellules biologiques.  However, some wavelength ranges are not useful for biological cells.
Certaines plages de longueurs d'onde de la lumière sont même néfastes à la culture de cellules biologiques ; la plage des infrarouges (en particulier la plage de longueur d'onde de 780 nm à 2500 nm) est ainsi néfaste car elle engendre un réchauffement du milieu sans bénéfice pour le milieu, ce qui oblige à prévoir des moyens particuliers pour refroidir le milieu ou en tout cas pour contenir sa température dans une plage bénéfique à la culture des cellules ; la plage des ultraviolets est elle aussi parfois néfaste à la culture de certaines cellules biologiques.  Some wavelength ranges of light are even harmful to the culture of biological cells; the infrared range (in particular the wavelength range of 780 nm to 2500 nm) is thus harmful because it generates a heating of the medium without benefit for the medium, which requires to provide special means for cooling the medium or in any case to contain its temperature in a range beneficial to the culture of the cells; the ultraviolet range is also sometimes harmful to the culture of certain biological cells.
Ceci est le cas, en particulier lorsque les cellules biologiques cultivées sont des micro-algues. Le but de l'invention est ainsi de permettre de réaliser un photobioréacteur fermé dont le vitrage de face avant qui est situé entre la source lumineuse et le milieu de culture, d'une part autorise le passage du rayonnement lumineux favorable à la culture (c'est-à-dire correspondant à la plage spectrale favorable au milieu), afin d'atteindre une efficacité élevée et d'autre part réfléchit le rayonnement infrarouge néfaste à la culture.  This is the case, especially when the cultured biological cells are microalgae. The object of the invention is thus to make it possible to produce a closed photobioreactor whose front face glazing which is located between the light source and the culture medium, on the one hand allows the passage of light radiation favorable to the culture (c that is to say, corresponding to the spectral range favorable to the medium), in order to achieve a high efficiency and on the other hand reflects infrared radiation harmful to the culture.
Il faut comprendre ici que l'action de réflexion du rayonnement infrarouge est différente d'une action d'absorption du rayonnement infrarouge.  It should be understood here that the reflection action of infrared radiation is different from an action of absorption of infrared radiation.
En effet, il est connu que la couleur du substrat de face avant, ou tout au moins la couleur d'un élément constituant ce substrat de face avant, peut engendrer une absorption d'une partie du rayonnement infrarouge ; ce rayonnement infrarouge ne peut donc pas atteindre le milieu de culture ; toutefois, une telle absorption est néfaste car elle engendre nécessairement un réchauffement du substrat de face avant qui gêne la culture car cette chaleur se transmet au milieu, alors qu'une réflexion du rayonnement infrarouge n'engendre pas de réchauffement du substrat de face avant et évite ainsi une transmission de chaleur au milieu. Indeed, it is known that the color of the front-face substrate, or at least the color of an element constituting this front-face substrate, can cause absorption of a portion of the infrared radiation; this Infrared radiation can not reach the culture medium; however, such an absorption is harmful because it necessarily generates a warming of the front face substrate which hinders the culture because this heat is transmitted to the medium, whereas a reflection of the infrared radiation does not cause warming of the front face substrate and thus avoids a heat transmission in the middle.
L'invention a ainsi pour objet, dans son acception la plus large, un photobioréacteur selon la revendication 1 . Ce photobioréacteur comporte une enceinte pour la culture de cellules à l'intérieur de cette enceinte, cette enceinte présentant un vitrage de face avant non opaque, ledit vitrage de face avant présentant une surface intérieure en contact avec l'intérieur de l'enceinte, le photobioréacteur étant remarquable en ce que ledit vitrage de face avant comporte un substrat qui est muni d'un empilement de couches minces comportant une alternance de « n » couches fonctionnelles métalliques, notamment de couches fonctionnelles à base d'argent ou d'alliage métallique contenant de l'argent, et de « (n + 1 ) » revêtements antireflet, avec n nombre entier > 3, chaque revêtement antireflet comportant au moins une couche antireflet, de manière à ce que chaque couche fonctionnelle soit disposée entre deux revêtements antireflet.  The invention thus has, in its broadest sense, a photobioreactor according to claim 1. This photobioreactor comprises an enclosure for culturing cells inside this chamber, this chamber having a non-opaque front face glazing, said front face glazing having an inner surface in contact with the interior of the enclosure, the photobioreactor being remarkable in that said front-face glazing comprises a substrate which is provided with a stack of thin layers comprising an alternation of "n" metal functional layers, in particular functional layers based on silver or metal alloy containing silver, and "(n + 1)" antireflection coatings, with n integer> 3, each antireflection coating having at least one antireflection layer, so that each functional layer is disposed between two antireflection coatings.
II existe certes des empilements de couches minces ou des revêtements sans couche fonctionnelle métallique et qui empêchent le passage du rayonnement de proche infrarouge ; toutefois, ces empilements de couches minces ou revêtements d'une part présentent généralement une transmission dans la plage spectrale favorable au milieu qui n'est pas très élevée (de l'ordre de 60 %, voire moins) et d'autre part absorbent pour l'essentiel le proche infrarouge ; utiliser de tels empilements de couches minces ou revêtements ne permettrait pas d'atteindre une efficacité élevée pour la culture de cellules biologiques du fait des pertes de transmission dans la plage spectrale favorable au milieu et engendrerait nécessairement un réchauffement du vitrage de face avant du photobioréacteur du fait de l'absorption par le vitrage de face avant dans le proche infrarouge. Au contraire, un empilement de couches minces à au moins trois couches fonctionnelles métalliques présente le double avantage : There are certainly stacks of thin layers or coatings without a metallic functional layer and which prevent the passage of near-infrared radiation; however, these stacks of thin layers or coatings on the one hand generally have a transmission in the spectral range favorable to the medium which is not very high (of the order of 60% or less) and on the other hand absorb for the essential near infrared; using such stacks of thin layers or coatings would not achieve a high efficiency for culturing biological cells due to transmission losses in the spectral range favorable to the environment and would necessarily cause a warming of the front face glazing of the photobioreactor of the made of the absorption by the glazing of front face in the near infrared. On the contrary, a stack of thin layers with at least three metallic functional layers has the double advantage:
- d'une part de permettre d'obtenir une transmission élevée dans la plage spectrale favorable au milieu (supérieure à 70 %, voire supérieure à 75 %), et  on the one hand, to make it possible to obtain a high transmission in the medium-favorable spectral range (greater than 70%, or even greater than 75%), and
- d'autre part de ne pas absorber le proche infrarouge, mais de le réfléchir pour l'essentiel ; ainsi, la présence d'un tel empilement permet d'atteindre une efficacité élevée en raison des faibles pertes de transmission dans la plage spectrale favorable au milieu, permet d'empêcher les infrarouges d'atteindre le milieu de culture, sans engendrer d'augmentation de la température de la surface intérieure du vitrage de face avant, celle qui est en contact avec l'intérieur de l'enceinte.  - on the other hand not to absorb the near infrared, but to think about it for the most part; thus, the presence of such a stack makes it possible to reach a high efficiency because of the low transmission losses in the medium-favorable spectral range, makes it possible to prevent infrared from reaching the culture medium, without causing an increase. the temperature of the inner surface of the front-face glazing, the one that is in contact with the interior of the enclosure.
La notion « d'empilement de couches minces » désigne ici la totalité des couches minces présentent sur la face du substrat considéré. Cette présence est observée par des techniques usuelles de microscopie électronique à balayage (MEB), de microscopie électronique à transmission (MET), ou encore de spectrométrie de masse des ions secondaires (SIMS).  The concept of "stack of thin layers" here designates all the thin layers present on the face of the substrate in question. This presence is observed by standard techniques of scanning electron microscopy (SEM), transmission electron microscopy (TEM), or secondary ion mass spectrometry (SIMS).
De préférence, l'empilement de couches minces à au moins trois couches fonctionnelles métalliques est disposé sur une face du substrat autre que la surface intérieure du vitrage qui est en contact avec l'intérieur de l'enceinte ; ainsi, la réflexion du rayonnement dans le proche infrarouge est encore plus efficace.  Preferably, the stack of thin layers with at least three metal functional layers is disposed on a face of the substrate other than the inner surface of the glazing which is in contact with the inside of the enclosure; thus, the reflection of near-infrared radiation is even more effective.
Dans ce type d'empilement à au moins trois couches fonctionnelles métalliques, chaque couche fonctionnelle métallique se trouve disposée entre deux revêtements antireflet comportant chacun au moins une (et en général plusieurs) couche(s) antireflet qui est (sont chacune) en un matériau diélectrique du type nitrure et notamment nitrure de silicium ou d'aluminium et/ou du type oxyde. Du point de vue optique, le but de ces revêtements qui encadrent chaque couche fonctionnelle est « d'antirefléter » cette couche fonctionnelle ; les couches antireflet ne sont pas, par nature, des couches métalliques. Un revêtement de blocage très fin est toutefois intercalé parfois entre un ou chaque revêtement antireflet et une couche fonctionnelle adjacente : un revêtement de blocage disposé sous la couche fonctionnelle en direction du substrat et/ou un revêtement de blocage disposé sur la couche fonctionnelle à l'opposé du substrat et qui protège cette couche d'une éventuelle dégradation lors du dépôt du revêtement antireflet supérieur et lors d'un éventuel traitement thermique à haute température, du type bombage et/ou trempe. Ce revêtement peut présenter une nature métallique ou oxydée et notamment une nature sous-oxydée ; toutefois, son action sur les caractéristiques de transmission ou de réflexion des rayonnements est en général négligée. In this type of stack with at least three metallic functional layers, each metallic functional layer is disposed between two antireflection coatings each comprising at least one (and in general several) antireflection layer (s) which is (are each) of a material dielectric nitride type and in particular silicon nitride or aluminum and / or oxide type. From an optical point of view, the purpose of these coatings which frame each functional layer is to "antireflect" this functional layer; the antireflection layers are not, by nature, metal layers. A very thin blocking coating is however sometimes interposed between one or each antireflection coating and an adjacent functional layer: a blocking coating disposed under the functional layer in the direction of the substrate and / or a blocking coating disposed on the functional layer to the opposite of the substrate and which protects this layer from possible degradation during the deposition of the upper antireflection coating and during a possible heat treatment at high temperature, of the bending and / or quenching type. This coating may have a metallic or oxidized nature and in particular a sub-oxidized nature; however, its effect on radiation transmission or reflection characteristics is generally neglected.
Les épaisseurs des couches évoquées dans le présent document sont des épaisseurs physiques, ou réelles (et non pas des épaisseurs optiques).  The layer thicknesses discussed herein are physical or actual thicknesses (and not optical thicknesses).
Par ailleurs, lorsqu'il est fait état d'un positionnement vertical d'une couche (ex. : en dessous /au-dessus), c'est toujours en considérant que le substrat porteur est positionné horizontalement, en bas, avec l'empilement au-dessus de lui ; Lorsqu'il est précisé qu'une couche est déposée directement sur une autre, cela signifie qu'il ne peut y avoir une (ou plusieurs) couche(s) intercalée(s) entre ces deux couches. Le rang des couches fonctionnelles est ici toujours défini en partant du substrat porteur de l'empilement (substrat sur la face duquel est déposé l'empilement).  Moreover, when a vertical positioning of a layer is mentioned (eg below / above), it is always considering that the carrier substrate is positioned horizontally, at the bottom, with the stacking above him; When it is specified that one layer is deposited directly on another, it means that there can be one (or more) layer (s) interposed (s) between these two layers. The rank of the functional layers is here always defined starting from the carrier substrate of the stack (substrate on the face of which the stack is deposited).
La couche antireflet qui est au minimum comprise dans chaque revêtement antireflet, comme défini ci-avant, présente un indice optique mesuré, comme habituellement, à 550 nm compris entre 1 ,8 et 2,5 en incluant ces valeurs, ou, de préférence, entre 1 ,9 et 2,3 en incluant ces valeurs, c'est-à-dire un indice optique que l'on peut considérer comme haut.  The antireflection layer which is at least included in each antireflection coating, as defined above, has an optical index measured, as usual, at 550 nm between 1.8 and 2.5 including these values, or, preferably, between 1, 9 and 2,3 including these values, ie an optical index that can be considered high.
Dans une variante particulière, la dernière couche du premier revêtement antireflet sous-jacent à la première couche fonctionnelle en partant du substrat est une couche de mouillage à base d'oxyde cristallisé (i.e. : non amorphe), notamment à base d'oxyde de zinc, éventuellement dopé à l'aide d'au moins un autre élément, comme l'aluminium et ce premier revêtement antireflet sous-jacent à la première couche fonctionnelle peut comporter en outre une couche de lissage, en un oxyde mixte non cristallisé (i.e. : amorphe), ladite couche de lissage étant en contact avec ladite couche de mouillage sus-jacente. Comme cette couche de mouillage et cette éventuelle couche de lissage appartiennent à un revêtement antireflet, ce sont de fait des couches antireflet. In a particular variant, the last layer of the first antireflection coating underlying the first functional layer starting from the substrate is a crystallized oxide (ie: non-amorphous) wetting layer, in particular based on zinc oxide. , optionally doped with at least one other element, such as aluminum and this first antireflection coating underlying the first functional layer may further comprising a smoothing layer, a non-crystallized mixed oxide (ie: amorphous), said smoothing layer being in contact with said overlying fog layer. As this wetting layer and this optional smoothing layer belong to an antireflection coating, they are in fact antireflection layers.
Dans cette variante particulière, l'épaisseur de ladite couche de lissage représente, de préférence, environ 1 /6e de l'épaisseur dudit premier revêtement antireflet et environ la moitié de l'épaisseur de ladite première couche fonctionnelle. In this particular embodiment, the thickness of said smoothing layer is preferably about 1/6 th of the thickness of said first antireflection coating and about half the thickness of said first functional layer.
Dans une variante toute particulière, la dernière couche de chaque revêtement antireflet sous-jacent à une couche fonctionnelle est une couche de mouillage à base d'oxyde cristallisé, notamment à base d'oxyde de zinc, éventuellement dopé à l'aide d'au moins un autre élément, comme l'aluminium. Chaque couche de mouillage est de fait une couche antireflet.  In a very particular variant, the last layer of each antireflection coating underlying a functional layer is a wetting layer based on crystalline oxide, in particular based on zinc oxide, optionally doped with the aid of minus another element, like aluminum. Each wetting layer is an anti-reflective layer.
Dans une autre variante particulière, chaque revêtement antireflet qui est situé au-dessus d'une couche fonctionnelle comporte une couche à base de nitrure de silicium Si3N4 ou à base de nitrure d'aluminium AIN. In another particular variant, each antireflection coating which is situated above a functional layer comprises a layer based on silicon nitride Si 3 N 4 or based on aluminum nitride AIN.
Dans une autre variante particulière, lesdits revêtements antireflet comportent chacun au moins une couche à base de nitrure de silicium Si3N4 ou à base de nitrure d'aluminium AIN. In another particular variant, said antireflection coatings each comprise at least one layer based on silicon nitride Si 3 N 4 or based on aluminum nitride AIN.
Dans ces deux dernières variantes, le nitrure de silicium Si3N4 et le nitrure d'aluminium AIN peut éventuellement être dopé à l'aide d'au moins un autre élément, comme l'aluminium. Ces couches à base de Si3N4 et/ou AIN sont de fait des couches antireflet. In these last two variants, the silicon nitride Si 3 N 4 and the aluminum nitride AIN may optionally be doped with at least one other element, such as aluminum. These layers based on Si 3 N 4 and / or AIN are in fact antireflection layers.
Ainsi pour ces deux dernières variantes le substrat porteur de l'empilement de couches minces selon l'invention est apte à subir un traitement thermique sans dommage pour l'empilement de couches minces. Il peut donc éventuellement être bombés et/ou trempés après le dépôt de l'empilement de couches minces.  Thus, for these last two variants, the carrier substrate of the stack of thin layers according to the invention is capable of undergoing heat treatment without damage for the stack of thin layers. It can therefore possibly be curved and / or tempered after the deposition of the stack of thin layers.
Si le substrat porteur de l'empilement est trempé, il est mécaniquement très résistant. Le substrat porteur de l'empilement, lorsqu'il est bombé, permet de réaliser une face avant cintrée pour un photobioréacteur tubulaire. If the carrier substrate of the stack is quenched, it is mechanically very strong. The carrier substrate of the stack, when curved, allows for a curved front face for a tubular photobioreactor.
L'épaisseur de chaque couche fonctionnelle est, de préférence, comprise entre 8 et 20 nm en incluant ces valeurs, voire entre 10 et 18 en nm en incluant ces valeurs, et de préférence encore entre 11 et 15 en nm en incluant ces valeurs.  The thickness of each functional layer is preferably between 8 and 20 nm including these values, or even between 10 and 18 in nm including these values, and more preferably between 11 and 15 in nm including these values.
L'épaisseur totale des couches métalliques fonctionnelles métalliques est de préférence supérieure à 30 nm et cette épaisseur totale est :  The total thickness of the metal functional metallic layers is preferably greater than 30 nm and this total thickness is:
- notamment comprise entre 30 et 60 nm en incluant ces valeurs, voire cette épaisseur totale est comprise entre 35 et 50 nm pour un empilement de couches minces à trois couches fonctionnelles métalliques (en particulier chacune à base d'argent, voire en argent),  - In particular between 30 and 60 nm including these values, or this total thickness is between 35 and 50 nm for a thin film stack with three functional metal layers (in particular each based on silver, or even silver),
- voire est comprise entre 40 et 60 nm pour un empilement de couches minces à quatre couches fonctionnelles métalliques (en particulier chacune à base d'argent, voire en argent).  - Or is between 40 and 60 nm for a thin film stack with four functional metal layers (in particular each based on silver or silver).
Dans une variante de l'invention, le vitrage de face avant comporte en outre au moins un empilement de couches minces antireflet ne comportant pas de couche fonctionnelle métallique ; cet empilement de couches minces antireflet ne comportant pas de couche fonctionnelle métallique est situé sur une surface d'un substrat autre que la surface sur laquelle est disposé l'empilement de couches minces à plusieurs couches fonctionnelles métalliques.  In a variant of the invention, the front-face glazing further comprises at least one stack of thin antireflection layers having no metallic functional layer; this antireflection thin film stack having no metallic functional layer is located on a surface of a substrate other than the surface on which is arranged the thin film stack with several functional metal layers.
Un tel empilement de couches minces antireflet peut être disposé sur la surface extérieure ou sur la surface intérieure du vitrage de face avant. Un tel empilement de couches minces antireflet, et a fortiori deux empilements de couches minces antireflet disposés respectivement sur la surface extérieure et sur la surface intérieure du vitrage de face avant permet(tent) d'augmenter encore la haute transmission du vitrage dans la plage spectrale favorable au milieu sans dégrader la haute réflexion dans l'infrarouge.  Such a stack of thin antireflection layers may be disposed on the outer surface or on the inner surface of the front face glazing. Such a stack of thin antireflection layers, and a fortiori two stacks of thin antireflection layers disposed respectively on the outer surface and on the inner surface of the front face glazing allows (tent) to further increase the high transmittance of the glazing in the spectral range. favorable to the environment without degrading the high reflection in the infrared.
Pour augmenter la quantité de lumière favorable au milieu qui traverse le vitrage de face avant, il est préférable que, à la manière de ce qui est connu de la demande internationale de brevet N° WO 2003/046617, le vitrage de face avant présente une surface extérieure texturée par une pluralité de motifs géométriques en relief par rapport au plan général de ladite surface, la surface desdits motifs comprenant chacun au moins deux points tels qu'il existe deux plans sécants entre eux contenant chacun l'un desdits deux points et réunissant les deux conditions suivantes : To increase the amount of light favorable to the medium that passes through the front face glazing, it is preferable that, in the manner of what is known from International Patent Application No. WO 2003/046617, the front face glazing has an outer surface textured by a plurality of geometric patterns in relief relative to the general plane of said surface, the surface of said patterns each comprising at least two points such that there are two intersecting planes between them each containing one of said two points and meeting the two following conditions:
- ces plans sont tous deux perpendiculaires au plan général de la surface texturée, et  these planes are both perpendicular to the general plane of the textured surface, and
- ces plans contiennent chacun l'une des deux droites perpendiculaires à ladite surface et passant par l'un desdits deux points.  these planes each contain one of the two straight lines perpendicular to said surface and passing through one of said two points.
Il est également possible que le vitrage de face avant présente une surface extérieure texturée à la manière de ce qui est connu des demandes internationales de brevet N° WO 2006/134300, WO 2006/134301 ou WO 2010/084290.  It is also possible that the front-face glazing has a textured outer surface in the manner of what is known from International Patent Applications No. WO 2006/134300, WO 2006/134301 or WO 2010/084290.
La présente invention concerne ainsi un substrat porteur d'un empilement de couches minces selon l'invention et formant éventuellement tout seul le vitrage de face avant ; toutefois, ce substrat est, de préférence, associé à au moins un autre substrat afin de former un vitrage de face avant feuilleté, ledit substrat porteur de l'empilement de couches minces pouvant être bombé et/ou trempé. The present invention thus relates to a carrier substrate of a stack of thin layers according to the invention and possibly forming alone the front face glazing; however, this substrate is preferably associated with at least one other substrate to form a laminated front face glazing, said carrier substrate of the thin film stack being curved and / or tempered.
Le substrat, ou chaque substrat, du vitrage de face avant est de préférence clair, mais il peut aussi être coloré. Un des substrats au moins notamment peut être en verre coloré dans la masse. Le choix du type de coloration va dépendre des valeurs de transmission lumineuse recherchées pour certaines plages de longueurs d'ondes du domaine visible pour le vitrage de face avant une fois sa fabrication achevée.  The substrate, or each substrate, of the front-face glazing is preferably clear, but it can also be colored. At least one of the substrates may be colored glass in the mass. The choice of the type of coloration will depend on the desired light transmission values for certain wavelength ranges of the visible range for the front face glazing once its manufacture is complete.
Le vitrage de face avant selon l'invention peut présenter une structure feuilletée, associant notamment au moins deux substrats rigides du type verre par au moins une feuille de polymère thermoplastique, afin de présenter une structure de type verre/empilement de couches minces/feuille(s) de polymère/verre. Le polymère peut notamment être à base de polyvinylbutyral PVB, éthylène vinylacétate EVA, polyéthylène téréphtalate PET, polychlorure de vinyle PVC. The front-face glazing according to the invention may have a laminated structure, in particular associating at least two rigid substrates of the glass type with at least one thermoplastic polymer sheet, in order to present a glass / thin-film / sheet-like structure ( s) polymer / glass. The polymer may especially be based on polyvinyl butyral PVB, ethylene vinyl acetate EVA, PET polyethylene terephthalate, PVC polyvinyl chloride.
Le vitrage de face avant peut alors présenter une structure de type : verre/empilement de couches minces/feuille(s) de polymère/verre, ou encore : verre/feuille(s) de polymère/empilement de couches minces/feuille(s) de polymère/verre.  The front face glazing can then have a structure of the type: glass / stack of thin layers / sheet (s) of polymer / glass, or: glass / polymer sheet (s) / stack of thin layers / sheet (s) polymer / glass.
Le vitrage de face avant peut être bombé et/ou trempé en étant constitué d'un seul substrat, celui muni de l'empilement. Il s'agit alors d'un vitrage dit « monolithique ». Dans le cas où il est bombé, notamment en vue de constituer un vitrage de face avant d'un photoréacteur tubulaire, l'empilement de couches minces se trouve alors sur une face au moins partiellement non plane.  The front face glazing can be curved and / or tempered by being constituted by a single substrate, the one provided with the stack. It is then a glazing called "monolithic". In the case where it is curved, especially in order to constitute a front face glazing of a tubular photoreactor, the stack of thin layers is then on an at least partially non-planar face.
Lorsque le vitrage de face avant est monolithique ou feuilleté, au moins le substrat porteur de l'empilement peut être en verre bombé ou trempé, ce substrat pouvant être bombé ou trempé avant ou après le dépôt de l'empilement.  When the front face glazing is monolithic or laminated, at least the carrier substrate of the stack may be curved or tempered glass, this substrate being curvable or tempered before or after the deposition of the stack.
Ne choisir que des substrats en verre pour réaliser le vitrage de face avant permet de réaliser un vitrage :  Choosing only glass substrates for the glazing of the front face makes it possible to produce glazing:
- dont la transparence est stable dans le temps, alors que ce n'est pas le cas de toutes les matières plastiques : le PE, le PMMA peuvent perdent leur transparence dans le temps et le PVC peut prendre une coloration jaunâtre ;  - whose transparency is stable over time, whereas this is not the case for all plastics: PE, PMMA may lose their transparency over time and the PVC may turn yellowish;
- complètement inerte chimiquement, ne relâchant aucun composé organique à l'usage, ce qui n'est pas le cas de toutes les matières plastiques ;  - completely chemically inert, not releasing any organic compound for use, which is not the case for all plastics;
- résistant aux UV, alors qui ce n'est pas le cas de toutes les matières plastiques.  - UV resistant, which is not the case for all plastics.
Ces avantages sont aussi obtenus lorsqu'un substrat organique est intégré au vitrage de face avant mais que ce substrat est lui-même pris en sandwich entre deux substrats en verre (vitrage feuilleté).  These advantages are also obtained when an organic substrate is integrated with the front-face glazing but this substrate is itself sandwiched between two glass substrates (laminated glazing).
Une structure feuilletée, pour laquelle tous les composants sont ainsi en contact les uns avec les autres, permet de réaliser un vitrage de face avant présentant une transmission énergétique par conduction élevée ; de ce fait, la chaleur produite par le milieu peut être évacuée à travers le vitrage de face avant par conduction et ce, malgré la présence de l'empilement de couches minces (qui s'oppose par ailleurs à la transmission de cette chaleur par radiation, en raison de son caractère bas-émissif). A laminated structure, for which all the components are thus in contact with each other, allows a front face glazing having high energy transmission by conduction; as a result, the heat produced by the medium can be evacuated through the front face glazing by conduction, despite the presence of the stack of thin layers (which is also opposed to the transmission of this heat by radiation). because of its low-emissivity character).
Au contraire, un vitrage de face avant multiple qui intègre au moins un espace intercalaire, du type double-vitrage ou triple vitrage, n'est pas conseillé car cet espace va s'opposer à l'évacuation de la chaleur produite par le milieu à travers le vitrage de face avant par conduction (et l'empilement de couches minces s'oppose par ailleurs à la transmission de cette chaleur par radiation en raison de son caractère bas-émissif).  On the contrary, a multiple front face glazing that incorporates at least one spacer space, double glazing type or triple glazing, is not advisable because this space will oppose the evacuation of the heat produced by the medium to through conduction front glazing (and the stack of thin layers is also opposed to the transmission of this heat by radiation due to its low-emissivity).
L'invention concerne en outre l'utilisation, pour réaliser un photobioréacteur selon l'invention, d'un substrat qui est muni d'un empilement de couches minces comportant une alternance de « n » couches fonctionnelles métalliques, notamment de couches fonctionnelles à base d'argent ou d'alliage métallique contenant de l'argent, et de « (n + 1 ) » revêtements antireflet, avec n nombre entier > 3, chaque revêtement antireflet comportant au moins une couche antireflet, de manière à ce que chaque couche fonctionnelle soit disposée entre deux revêtements antireflet. The invention furthermore relates to the use, for producing a photobioreactor according to the invention, of a substrate which is provided with a stack of thin layers comprising an alternation of "n" metal functional layers, in particular functional layers based on of silver or metal alloy containing silver, and "(n + 1)" antireflection coatings, with n integer> 3, each antireflection coating comprising at least one antireflection layer, so that each layer functional is arranged between two antireflection coatings.
Avantageusement, la présente invention permet de réaliser un vitrage de face avant présentant, pour la totalité du spectre solaire : Advantageously, the present invention makes it possible to produce a front-panel glazing having, for the entire solar spectrum:
- une transmission moyenne égale ou supérieure à 50 %, avec une transmission dans la plage spectrale favorable au milieu égale ou supérieure à an average transmission equal to or greater than 50%, with a transmission in the spectral range favorable to the medium equal to or greater than
70 %, une transmission dans le domaine de l'UV proche de zéro et une transmission dans le domaine du proche infrarouge proche de zéro, et 70%, transmission in the UV range close to zero and transmission in the near-infrared range close to zero, and
- une réflexion moyenne inférieure à 50 %, avec une absorption /réflexion dans le domaine de l'UV supérieure à 50 % et proche de 100 % et une réflexion dans le domaine du proche infrarouge supérieure à 50 % et proche de 100 %. La présente invention permet en outre les échanges thermiques par conduction avec l'extérieur. an average reflection of less than 50%, with absorption / reflection in the UV range greater than 50% and close to 100% and reflection in the near-infrared range of greater than 50% and close to 100%. The present invention also allows heat exchange by conduction with the outside.
Les détails et caractéristiques avantageuses de l'invention ressortent des exemples non limitatifs suivants, illustrés à l'aide des figures ci-jointes illustrant : The details and advantageous features of the invention emerge from the following nonlimiting examples, illustrated with the aid of the attached figures illustrating:
en figure 1 , une vue en coupe verticale d'un photobioréacteur selon l'invention qui est plan et incliné ;  in Figure 1, a vertical sectional view of a photobioreactor according to the invention which is plane and inclined;
en figure 2, une vue en perspective d'un photobioréacteur selon l'invention qui est cylindrique et creux ;  in FIG. 2, a perspective view of a photobioreactor according to the invention which is cylindrical and hollow;
en figure 3, une vue en perspective d'un photobioréacteur selon l'invention qui est cylindrique et plein ;  in FIG. 3, a perspective view of a photobioreactor according to the invention which is cylindrical and solid;
en figure 4, une vue en coupe d'une variante de réalisation du vitrage de face avant selon l'invention ;  in Figure 4, a sectional view of an alternative embodiment of the front panel glazing according to the invention;
- en figure 5, une vue en coupe d'une autre variante de réalisation du vitrage de face avant selon l'invention ;  - In Figure 5, a sectional view of another alternative embodiment of the front face glazing according to the invention;
en figure 6, la courbe du coefficient d'absorption des micro-algues testées et la courbe de transmission lumineuse des vitrages de face avant testés, en fonction de la longueur d'onde ; et  in FIG. 6, the curve of the absorption coefficient of the microalgae tested and the light transmission curve of the front panel glazings tested, as a function of the wavelength; and
- en figure 7, un empilement à trois fonctionnelles selon l'invention, chaque couche fonctionnelle n'étant pas pourvue d'un revêtement de sous- blocage mais étant pourvue d'un revêtement de sur-blocage et l'empilement étant en outre pourvu d'un revêtement de protection optionnel.  - In Figure 7, a functional three stack according to the invention, each functional layer is not provided with a sub-blocking coating but being provided with an over-blocking coating and the stack being further provided an optional protective coating.
Dans les figures 4, 5, et 7, les proportions entre les épaisseurs des différentes couches ne sont pas rigoureusement respectées afin de faciliter leur lecture. In Figures 4, 5 and 7, the proportions between the thicknesses of the different layers are not rigorously respected to facilitate their reading.
La figure 1 illustre un photoréacteur 1 du type « plans », incliné par rapport à l'horizontale, pour lequel le milieu cultivé est mobile entre deux substrats plans qui sont ni à l'horizontale, ni à la verticale. Le photobioréacteur 1 comporte une enceinte 2 pour la culture de cellules à l'intérieur I de cette enceinte. Cette enceinte 2 comporte un substrat de face 3 avant non opaque et un substrat de face arrière 4 qui est généralement opaque (même si cela n'est pas une obligation). L'enceinte 2 comporte par ailleurs un montant bas 5, un montant haut 5' et des montant latéraux (non illustrés), qui assurent la jonction hermétique à la périphérique respectivement basse, haute et sur les côtés entre le substrat de face 3 avant et le substrat de face arrière 4. Figure 1 illustrates a photoreactor 1 of the "planes" type, inclined relative to the horizontal, for which the cultivated medium is movable between two flat substrates which are neither horizontal nor vertical. Photobioreactor 1 comprises an enclosure 2 for culturing cells inside I of this chamber. This enclosure 2 comprises a non-opaque front face substrate 3 and a backside substrate 4 which is generally opaque (even if this is not an obligation). The chamber 2 furthermore comprises a low upright 5, a high upright 5 'and lateral uprights (not shown) which provide the hermetic connection to the device, respectively low, high and on the sides between the front face substrate 3 and the backside substrate 4.
Le photobioréacteur 1 comporte par ailleurs un système de pompage (non illustré) qui aspire le milieu de culture à proximité du montant bas pour le refouler à proximité du montant haut.  The photobioreactor 1 also comprises a pumping system (not shown) which sucks the culture medium near the low amount to push it close to the high amount.
Le milieu de culture 6 est ainsi animé d'un mouvement de haut en bas, sous l'effet de la gravité, par ruissellement sur la face intérieure du substrat de face arrière 4, comme illustré par les doubles flèches.  The culture medium 6 is thus driven from top to bottom, under the effect of gravity, by trickling on the inside face of the rear-face substrate 4, as illustrated by the double arrows.
Le substrat de face 3 avant et le substrat de face arrière 4 sont disposés parallèles l'un à l'autre.  The front face substrate 3 and the back face substrate 4 are arranged parallel to each other.
Le substrat de face arrière 4 (et par conséquent aussi le substrat de face 3) est orienté d'un angle a de l'ordre de 30 ° ou 45 ° par rapport à l'horizontal grâce à un châssis 7.  The rear face substrate 4 (and therefore also the face substrate 3) is oriented at an angle α of the order of 30 ° or 45 ° relative to the horizontal thanks to a frame 7.
Le vitrage de face avant 3 présente une surface intérieure 30 en contact avec l'intérieur I de l'enceinte 2 et une surface extérieure 31 en contact avec le milieu ambiant.  The front face glazing 3 has an inner surface 30 in contact with the interior I of the enclosure 2 and an outer surface 31 in contact with the environment.
Ici, un espace est prévu entre le milieu de culture 6 et la surface intérieure 30 du vitrage de face avant 3.  Here, a space is provided between the culture medium 6 and the inner surface 30 of the front face glazing 3.
Les figures 2 et 3 illustrent deux exemples de photoréacteurs dits « tubulaire », l'un en figure 2 où le milieu est cultivé, mobile ou immobile, dans un cylindrique plein (colonne) et l'autre en figure 3 où le milieu est cultivé, mobile ou immobile, dans un cylindrique creux. FIGS. 2 and 3 illustrate two examples of so-called "tubular" photoreactors, one in FIG. 2 where the medium is cultured, mobile or immobile, in a solid cylindrical column and the other in FIG. 3 where the medium is cultured , mobile or immobile, in a hollow cylindrical.
Chacun de ces deux exemples, l'enceinte 2 comporte un substrat de face avant 3 non opaque de forme cylindrique. A la différence de la version en cylindre plein, pour la version en cylindre creux l'enceinte 2 comporte en outre un substrat de face arrière 4 qui est opaque ou non et qui est également de forme cylindrique mais selon un rayon plus petit que celui du substrat de face avant 3. Les rayons de ces deux cylindres sont de préférence concentriques afin que l'espace entre les deux substrats soit toujours le même le long de l'axe de l'enceinte. Each of these two examples, the chamber 2 comprises a non-opaque front face substrate 3 of cylindrical shape. Unlike the solid cylinder version, for the hollow cylinder version the chamber 2 further comprises a rear face substrate 4 which is opaque or not and which is also of cylindrical shape but with a radius smaller than that of the front face substrate 3. The radii of these two cylinders are preferably concentric so that the space between the two substrates is always the same along the axis of the enclosure.
Les figures 4 et 5 illustrent deux exemples de structures de vitrages de face avant feuilletés pour photobioréacteur. Figures 4 and 5 illustrate two examples of laminated front face glazing structures for photobioreactor.
Sur ces deux figures, le vitrage de face avant 3 est constitué d'un vitrage feuilleté comportant deux substrats en verre : le substrat 10, sur une face duquel est déposé l'empilement de couches minces 1 1 , et un second substrat 400. Une feuille de matière plastique 300 est située entre les deux substrats en verre.  In these two figures, the front face glazing 3 consists of a laminated glazing unit comprising two glass substrates: the substrate 10, on one side of which is deposited the stack of thin layers 1 1, and a second substrate 400. plastic sheet 300 is located between the two glass substrates.
Le substrat 10 est plus à l'extérieur de l'enceinte que le second substrat 400 et l'empilement de couches minces 1 1 est situé sur la face du substrat 10 qui est orientée vers la feuille de matière plastique 300 intercalaire. L'empilement de couches minces 1 1 est disposé en face 2, en considérant, comme habituellement, que la face 1 est la face du vitrage la plus à l'extérieur et que les faces sont numérotées par ordre croissant en partant de la face la plus à l'extérieur.  The substrate 10 is more outside the enclosure than the second substrate 400 and the stack of thin layers January 1 is located on the face of the substrate 10 which is oriented towards the interlayer plastic sheet 300. The stack of thin layers 1 1 is disposed in face 2, considering, as usual, that the face 1 is the face of the outermost pane and that the faces are numbered in ascending order from the face of the more outside.
La surface intérieure 30 du vitrage de face avant 3 est ainsi constituée par la face du second substrat 400 la plus à l'intérieur et la surface extérieure 31 du vitrage de face avant 3 est ainsi constituée par la face du substrat 10 la plus à l'extérieur.  The inner surface 30 of the front face glazing 3 is thus constituted by the face of the second innermost substrate 400 and the outer surface 31 of the front face glazing 3 is thus constituted by the face of the substrate 10. 'outside.
En figure 5, le vitrage de face avant 3 comporte deux empilements de couches minces antireflet 12, 13, situés respectivement sur la surface extérieure 31 et sur la surface intérieure 30.  In FIG. 5, the front face glazing 3 comprises two stacks of thin antireflection layers 12, 13, situated respectively on the outer surface 31 and on the inner surface 30.
Chacun de ces empilements de couches minces antireflet ne comporte pas de couche fonctionnelle métallique. Il pourrait être envisagé de ne prévoir qu'un seul empilement de couches mince antireflet, situé sur la surface extérieure 31 ou sur la surface intérieure 30. Each of these antireflection thin film stacks does not have a metallic functional layer. It could be envisaged to provide only a single antireflection thin layer stack, located on the outer surface 31 or on the inner surface 30.
La figure 6 illustre en ordonnée le coefficient d'absorption des micro- algues testées, en fonction de la longueur d'onde λ (en nanomètres) en abscisse.  FIG. 6 illustrates on the ordinate the absorption coefficient of the microalgae tested, as a function of the wavelength λ (in nanometers) on the abscissa.
Cette courbe permet d'appréhender l'absorption lumineuse des microalgues : cette absorption est élevée dans la gamme 400-500 nm, faible dans la gamme 500-650 nm, élevée dans la gamme 650-700 nm, puis faible au-delà. C'est un profil assez typique des micro-algues.  This curve makes it possible to apprehend the light absorption of microalgae: this absorption is high in the range 400-500 nm, low in the range 500-650 nm, high in the range 650-700 nm, then low beyond. This is a typical profile of micro-algae.
La figure 7 illustre une structure d'empilement à trois couches fonctionnelles 40, 80, 120, cette structure étant déposée sur le substrat 10 verrier, transparent.  FIG. 7 illustrates a stacking structure with three functional layers 40, 80, 120, this structure being deposited on the transparent glass substrate 10.
Chaque couche fonctionnelle 40, 80, 120, est disposée entre deux revêtements antireflet 20, 60, 100, 140, de telle sorte que la première couche fonctionnelle 40 en partant du substrat est disposée entre les revêtements antireflet 20, 60 ; la deuxième couche fonctionnelle 80 est disposée entre les revêtements antireflet 60, 100 et la troisième couche fonctionnelle 120 est disposée entre les revêtements antireflet 100, 140.  Each functional layer 40, 80, 120 is disposed between two antireflection coatings 20, 60, 100, 140, so that the first functional layer 40 starting from the substrate is disposed between the antireflection coatings 20, 60; the second functional layer 80 is disposed between the antireflection coatings 60, 100 and the third functional layer 120 is disposed between the antireflection coatings 100, 140.
Ces revêtements antireflet 20, 60, 100, 140, comportent chacun au moins une couche antireflet diélectrique 24, 26, 28 ; 62, 64, 66, 68 ; 102, 104, 106, 108 ; 142, 144.  These antireflection coatings 20, 60, 100, 140 each comprise at least one dielectric antireflection layer 24, 26, 28; 62, 64, 66, 68; 102, 104, 106, 108; 142, 144.
Eventuellement, d'une part chaque couche fonctionnelle 40, 80, 120, peut être déposée sur un revêtement de sous-blocage (non illustré) disposé entre le revêtement antireflet sous-jacent et la couche fonctionnelle et d'autre part chaque couche fonctionnelle peut être déposée directement sous un revêtement de sur-blocage 55, 95, 135 disposé entre la couche fonctionnelle et le revêtement antireflet sus-jacent à cette couche. Quatre exemples de vitrage avant ont été testés, numérotées de 1 à 4 ci- après. Ces quatre vitrages sont des vitrages feuilletés de structure : substrat en verre / feuille intercalaire en PVB / substrat en verre. Optionally, firstly, each functional layer 40, 80, 120 may be deposited on a sub-blocking coating (not illustrated) disposed between the underlying antireflection coating and the functional layer, and on the other hand each functional layer may be deposited directly under an over-blocking coating 55, 95, 135 disposed between the functional layer and the antireflection coating overlying this layer. Four examples of front glazing were tested, numbered from 1 to 4 below. These four glazings are laminated glass structures: glass substrate / interlayer sheet PVB / glass substrate.
Dans trois de ces vitrages, numérotées de 2 à 4 ci-après, a été incorporé un empilement de couches minces comportant au moins une couche fonctionnelle métallique, afin de réaliser des vitrages feuilletés de structure : substrat en verre porteur de l'empilement de couches minces / feuille intercalaire en PVB / substrat en verre.  In three of these glazings, numbered from 2 to 4 below, was incorporated a stack of thin layers comprising at least one metallic functional layer, in order to produce laminated glass structures: glass substrate carrying the stack of layers thin / PVB interlayer sheet / glass substrate.
Ainsi, l'exemple 1 est un exemple de référence présentant la même structure de substrat / feuille intercalaire / substrat, mais sans empilement de couches minces.  Thus, Example 1 is a reference example having the same substrate structure / spacer sheet / substrate, but without stacking thin layers.
Le tableau 1 suivant résume les matériaux et les épaisseurs de chaque couche et de chaque élément de la structure feuilletée en fonction de sa position vis-à-vis du substrat porteur de l'empilement (dernière ligne du tableau) ; les numéros de la 2e colonne correspondent aux références de la figure 7. The following table 1 summarizes the materials and the thicknesses of each layer and each element of the laminated structure as a function of its position vis-à-vis the carrier substrate of the stack (last row of the table); numbers of column 2 correspond to the references in Figure 7.
Figure imgf000018_0001
Tableau 1
Figure imgf000018_0001
Table 1
Dans tous les exemples ci-après l'empilement de couches minces est déposé sur un substrat en verre sodo-calcique clair d'une épaisseur de 1 ,6 mm, distribué par la société SAINT-GOBAIN.  In all the examples below, the stack of thin layers is deposited on a clear soda-lime glass substrate with a thickness of 1.6 mm, distributed by the company SAINT-GOBAIN.
Le substrat 10 porteur de l'empilement est celui qui est positionné le plus proche du soleil, c'est-à-dire que lors des tests réalisés, il y avait, dans cet ordre : soleil / substrat 10 / Empilement de couches minces 11 (sauf pour l'ex. 1 )/ intercalaire 300 / substrat 400 / micro-algues, comme visible en figure 4, avec le soleil au-dessus de la surface extérieure 31 de la face avant 3 et les micro-algues sous la surface intérieure 30 de la face avant 3.  The carrier substrate 10 of the stack is the one that is positioned closest to the sun, that is to say that during the tests carried out, there were, in this order: sun / substrate 10 / stack of thin layers 11 (except for example 1) / spacer 300 / substrate 400 / micro-algae, as shown in FIG. 4, with the sun above the outer surface 31 of the front face 3 and the micro-algae under the surface inside 30 of the front face 3.
Chaque revêtement antireflet 20, 60, 100 sous-jacent à une couche fonctionnelle 40, 80, 120 comporte une dernière couche de mouillage 28, 68, 108 à base d'oxyde de zinc cristallisé, dopé à l'aluminium et qui est au contact de la couche fonctionnelle 40, 80, 120 déposée juste au-dessus. Each antireflection coating 20, 60, 100 underlying a functional layer 40, 80, 120 comprises a final wetting layer 28, 68, 108 based on crystalline zinc oxide, doped with aluminum and which is in contact with of the functional layer 40, 80, 120 deposited just above.
Chaque revêtement antireflet 20, 60, 100, 140 comporte une couche 24, 64, 104, 144 à base de nitrure de silicium, dopé à l'aluminium. Ces couches sont importantes pour obtenir l'effet barrière à l'oxygène lors du traitement thermique, afin de préserver les couches fonctionnelles métalliques de l'attaque de l'oxygène lors d'un traitement thermique.  Each antireflection coating 20, 60, 100, 140 comprises a layer 24, 64, 104, 144 based on silicon nitride, doped with aluminum. These layers are important for obtaining the oxygen barrier effect during the heat treatment, in order to preserve the metal functional layers of the oxygen attack during a heat treatment.
Sur la figure 7 on constate que l'empilement se termine par une couche de protection optionnelle 200, qui n'est pas présente pour les exemples 2 à 4.  In FIG. 7 it can be seen that the stack ends with an optional protective layer 200, which is not present for examples 2 to 4.
Pour chacun des trois exemples d'empilement (ex. 2-4), les conditions de dépôt des couches, qui ont été déposées par pulvérisation (pulvérisation dite « cathodique magnétron »), sont les suivantes :  For each of the three stacking examples (eg 2-4), the deposition conditions of the layers, which have been deposited by sputtering ("cathodic magnetron sputtering"), are as follows:
Figure imgf000019_0001
Figure imgf000019_0001
Tableau 2 Du fait que chaque revêtement antireflet 60, 100, 140 qui est situé au- dessus d'une couche fonctionnelle 40, 80, 120 comporte une couche à base de nitrure de silicium, l'empilement de l'exemple 4 présente de plus l'avantage d'être trempables ou bombables et peut subir une opération d'intégration dans un vitrage feuilleté sans que ses propriétés optiques et thermiques ne soient modifiées. Table 2 Since each antireflection coating 60, 100, 140 which is located above a functional layer 40, 80, 120 has a silicon nitride layer, the stack of Example 4 further has the advantage of being hardenable or bumpable and may undergo an integration operation in a laminated glazing without its optical and thermal properties are modified.
Cela est particulièrement important pour permettre la réalisation de photoréacteurs dits « tubulaire » ; il est ainsi possible de déposer l'empilement de couches minces selon l'invention sur le substrat 10, puis de bomber ce substrat pour lui permettre de prendre une forme tubulaire.  This is particularly important to allow the realization of so-called "tubular" photoreactors; it is thus possible to deposit the stack of thin layers according to the invention on the substrate 10, then to bombard the substrate to enable it to take a tubular form.
Le tableau 3 résume pour les exemples 1 à 4 les principales caractéristiques optiques mesurées pour le vitrage feuilleté complet intégrant le substrat porteur de l'empilement : Table 3 summarizes for Examples 1 to 4 the main optical characteristics measured for the complete laminated glazing unit integrating the carrier substrate of the stack:
- la transmission photosynthétique, correspond à l'intégration du spectre d'absorption des micro-algues (celui de la figure 6), par le spectre solaire normalisé (norme ISO 9050 AM 1 ,5) et par la transmission du vitrage considérée pour ce spectre ; cela correspond à ce que les micro-algues "perçoivent" du spectre solaire, à la manière de ce que les yeux d'un être humain perçoivent de ce même spectre solaire ;  - the photosynthetic transmission, corresponds to the integration of the absorption spectrum of the micro-algae (that of figure 6), the standardized solar spectrum (norm ISO 9050 AM 1, 5) and the transmission of the glazing considered for this spectrum; this corresponds to what the micro-algae "perceive" from the solar spectrum, in the way that the eyes of a human being perceive from this same solar spectrum;
- l'efficacité comparée est l'efficacité de chacun des exemples 2 à 4, comparée à celle de l'exemple 1 , c'est-à-dire comparée à celle d'un vitrage feuilleté sans empilement de couches minces ;  the efficiency compared is the efficiency of each of Examples 2 to 4, compared with that of Example 1, that is to say compared to that of a laminated glazing without stacking thin layers;
- la TE est la transmission énergétique à travers le vitrage, en pourcentage, mesurée selon la norme ISO 9050 AM 1.5, c'est-à-dire la fraction d'énergie transmise directement à travers le vitrage aux micro-algues ;  TE is the energy transmission through the glazing, in percentage, measured according to the ISO 9050 AM 1.5 standard, that is to say the fraction of energy transmitted directly through the microalgae glazing;
- la RE est la réflexion énergétique à travers le vitrage, en pourcentage, mesurée selon la norme ISO 9050 AM 1.5, c'est-à-dire la fraction d'énergie réfléchie directement par le vitrage et qui ne peut pas atteindre les microalgues ; - la TTS correspond à l'abréviation en anglais de l'expression « Total Transmitted Sun » ; c'est la somme de la transmission énergétique totale à travers le vitrage, qui prend en considération à la fois la TE et l'énergie réémise par radiation par le vitrage en direction de l'intérieur du photobioréacteur, pour un vent extérieur moyen de 4 m /s ; - The RE is the energy reflection through the glazing, in percentage, measured according to the ISO 9050 AM 1.5 standard, that is to say the fraction of energy reflected directly by the glazing and which can not reach the microalgae; - the TTS corresponds to the abbreviation in English of the expression "Total Transmitted Sun"; it is the sum of the total energy transmission through the glazing, which takes into consideration both the TE and the energy re-emitted by radiation from the glazing towards the inside of the photobioreactor, for an average outside wind of 4 m / s;
- la TIR correspond à la transmission du vitrage sur la plage de longueur d'onde infrarouge de 780 nm à 2500 nm ; et  the TIR corresponds to the transmission of the glazing over the infrared wavelength range of 780 nm to 2500 nm; and
- la RIR correspond à la réflexion du vitrage sur la plage de longueur d'onde infrarouge de 780 nm à 2500 nm.  the RIR corresponds to the reflection of the glazing over the infrared wavelength range of 780 nm to 2500 nm.
Figure imgf000021_0001
Figure imgf000021_0001
Tableau 3  Table 3
On constate ainsi que la transmission de la lumière utile à la croissance des micro-algues est sensiblement la même à travers les vitrages des exemples 2 à 4 ; elle est environ 80 % inférieure à celle d'un vitrage feuilleté sans empilement (ex. 1 ). It is thus found that the transmission of light useful for the growth of microalgae is substantially the same through the glazings of Examples 2 to 4; it is about 80% lower than that of laminated glazing without stacking (eg 1).
Un photobioréacteur dont le vitrage de face avant comporte un empilement à une (ex. 1 ), deux (ex. 2) ou trois (ex. 3) couche(s) fonctionnelle(s) métallique(s) présente donc à première vue une efficacité moindre.  A photobioreactor in which the front-face glazing comprises a stack of one (eg 1), two (eg 2) or three (eg 3) metallic functional layer (s), therefore, at first sight less effective.
Toutefois, le tableau 3 montre que d'une part la transmission énergétique de l'exemple 4 est meilleure que celle des exemples 1 à 3, puisque c'est la plus petite et d'autre part que la transmission énergétique totale de l'exemple 4 est meilleure que celle des exemples 1 à 3 puisque c'est la plus petite, alors même que la transmission énergétique des exemples 2 (à une couche fonctionnelle) et 3 (à deux couches fonctionnelles) est sensiblement identique. However, Table 3 shows that on the one hand the energetic transmission of Example 4 is better than that of Examples 1 to 3, since it is the smallest and on the other hand that the total energy transmission of the example 4 is better than that of Examples 1 to 3 since it is the smallest, even though the energy transmission of Examples 2 (to a functional layer) and 3 (two functional layers) is substantially identical.
Le Tableau 3 montre par ailleurs la transmission dans l'infrarouge est quasiment nulle (moins de 10 %) pour l'exemple 4 alors qu'elle est relativement élevée pour les exemples 2 et 3 et que la réflexion dans l'infrarouge est très élevée (supérieure à 60 %) pour l'exemple 4 alors qu'elle est relativement basse et identique pour les exemples 2 et 3.  Table 3 furthermore shows that the transmission in the infrared is practically zero (less than 10%) for example 4 while it is relatively high for examples 2 and 3 and that the reflection in the infrared is very high. (greater than 60%) for Example 4 whereas it is relatively low and identical for Examples 2 and 3.
Les transmissions lumineuses des exemples 1 à 4 ont été rajoutées sur la figure 6. The light transmissions of Examples 1 to 4 have been added in FIG.
Chacun peut ainsi voir d'une part que la transmission lumineuse de l'exemple 4 est quasi-nulle dans le proche infrarouge (de 780 nm à 980 nm) alors qu'elle est bien plus faibles pour les exemples 1 à 3 et est nulle pour les longueurs d'onde plus grande et d'autre part que la transmission lumineuse de l'exemple 4 est celle qui se conforme le mieux aux attentes relativement à l'absorption des micro-algues puisque cette transmission lumineuse est élevée dans la gamme 400-500 nm, moins élevée dans la gamme 500-650 nm, puis à nouveau élevée dans la gamme 650-700 nm, puis faible au-delà.  Each can thus see, on the one hand, that the light transmission of Example 4 is almost zero in the near infrared (from 780 nm to 980 nm) whereas it is much lower for Examples 1 to 3 and is zero. for the longer wavelengths and secondly that the light transmission of Example 4 is the one that best meets the expectations for the absorption of microalgae since this light transmission is high in the range 400 -500 nm, lower in the range 500-650 nm, then again raised in the range 650-700 nm, then low beyond.
La présente invention permet ainsi d'atteindre une transmission très proche de la transmission lumineuse idéale qui serait une transmission de 100 % dans le domaine d'absorption des micro-algues et uniquement dans ce domaine d'absorption des micro-algues.  The present invention thus makes it possible to achieve a transmission very close to the ideal light transmission which would be a transmission of 100% in the absorption domain of microalgae and only in this area of absorption of microalgae.
La structure feuilletée du vitrage de face avant de l'exemple 4 présente en outre l'avantage de contrecarrer l'effet bas-émissif de l'empilement de couches minces vis-à-vis du milieu en permettant à la chaleur produite par le milieu d'être évacuée par conduction à travers la structure feuilletée malgré la présence de l'empilement de couches minces.  The laminated structure of the front-face glazing unit of Example 4 also has the advantage of counteracting the low-emissive effect of the stack of thin layers vis-à-vis the medium by allowing the heat produced by the medium to be removed by conduction through the laminated structure despite the presence of the stack of thin layers.
Il a ainsi été constaté que la température du milieu testé avec l'exemple 4 restait quasiment identique alors que dans les mêmes conditions la température du milieu testé avec l'exemple 1 était montée de 17 °C. Par ailleurs, l'utilisation d'un vitrage feuilleté intégrant une feuille intercalaire en matière plastique permet d'obtenir une transmission dans les UV inférieure à 1 %. Un empilement à quatre couches fonctionnelles métalliques, notamment quatre couches fonctionnelles à base d'argent ou d'alliage métallique contenant de l'argent, et de cinq revêtements antireflet de manière à ce que chaque couche fonctionnelle soit disposée entre deux revêtements antireflet présentera une transmission lumineuse assez proche de celle d'un empilement à trois couches fonctionnelles métalliques tel que celles de l'exemple 4. It was thus found that the temperature of the medium tested with Example 4 remained almost identical while under the same conditions the temperature of the medium tested with Example 1 was raised to 17 ° C. Moreover, the use of a laminated glazing unit incorporating a plastic interlayer sheet makes it possible to obtain a UV transmission of less than 1%. A stack of four metal functional layers, including four silver-based metal or silver-containing functional layers, and five anti-reflective coatings so that each functional layer is disposed between two anti-reflective coatings will have a transmission. luminous enough close to that of a stack with three functional metal layers such as those of Example 4.
La présente invention est décrite dans ce qui précède à titre d'exemple. Il est entendu que l'homme du métier est à même de réaliser différentes variantes de l'invention sans pour autant sortir du cadre du brevet tel que défini par les revendications. The present invention is described in the foregoing by way of example. It is understood that the skilled person is able to achieve different variants of the invention without departing from the scope of the patent as defined by the claims.

Claims

REVENDICATIONS
1 . Photobioréacteur (1 ) comportant une enceinte (2) pour la culture de cellules à l'intérieur (I) de cette enceinte, cette enceinte (2) présentant un vitrage de face avant (3) non opaque, ledit vitrage de face avant (3) présentant une surface intérieure (30) en contact avec l'intérieur (I) de l'enceinte (2), caractérisé en ce que ledit vitrage de face avant (3) comporte un substrat (10) qui est muni d'un empilement de couches minces (1 1 ) comportant une alternance de « n » couches fonctionnelles (40, 80, 120) métalliques, notamment de couches fonctionnelles à base d'argent ou d'alliage métallique contenant de l'argent, et de « (n + 1 ) » revêtements antireflet (20, 60, 100, 140), avec n nombre entier > 3, chaque revêtement antireflet comportant au moins une couche antireflet (24, 64, 104, 144), de manière à ce que chaque couche fonctionnelle (40, 80, 120) soit disposée entre deux revêtements antireflet (20, 60, 100, 140).  1. Photobioreactor (1) comprising an enclosure (2) for culturing cells inside (I) of this chamber, said chamber (2) having a non-opaque front face glazing (3), said front face glazing (3) ) having an inner surface (30) in contact with the interior (I) of the enclosure (2), characterized in that said front face glazing (3) comprises a substrate (10) which is provided with a stack thin layers (1 1) comprising an alternation of "n" metal functional layers (40, 80, 120), in particular silver-based or silver-containing metal-containing functional layers, and "(n + 1) »antireflection coatings (20, 60, 100, 140), with n integer> 3, each antireflection coating comprising at least one antireflection layer (24, 64, 104, 144), so that each functional layer (40, 80, 120) is disposed between two antireflection coatings (20, 60, 100, 140).
2. Photobioréacteur (1 ) selon la revendication 1 , caractérisé en ce que ledit empilement de couches minces (1 1 ) est disposé sur une face du substrat (10) autre que la surface intérieure (30) en contact avec l'intérieur (I) de l'enceinte (2).  2. photobioreactor (1) according to claim 1, characterized in that said stack of thin layers (1 1) is disposed on one side of the substrate (10) other than the inner surface (30) in contact with the inside (I ) of the enclosure (2).
3. Photobioréacteur (1 ) selon la revendication 1 ou 2, caractérisé en ce que ledit vitrage de face avant (3) est un vitrage feuilleté, ledit substrat (10) étant en verre et ledit vitrage de face avant (3) comportant en outre au moins un second substrat (400) en verre et une feuille de matière plastique (300) disposée entre les deux substrats en verre.  3. Photobioreactor (1) according to claim 1 or 2, characterized in that said front face glazing (3) is a laminated glazing, said substrate (10) being made of glass and said front face glazing (3) further comprising at least a second glass substrate (400) and a plastic sheet (300) disposed between the two glass substrates.
4. Photobioréacteur (1 ) selon l'une quelconque des revendications 1 à 3, caractérisé en ce que l'épaisseur totale des couches fonctionnelles métalliques est supérieure à 30 nm et est notamment comprise entre 30 et 60 nm en incluant ces valeurs, voire cette épaisseur totale est comprise entre 35 et 50 nm pour un empilement de couches minces à trois couches fonctionnelles métalliques, voire cette épaisseur totale est comprise entre 40 et 60 nm pour un empilement de couches minces à quatre couches fonctionnelles métalliques. 4. Photobioreactor (1) according to any one of claims 1 to 3, characterized in that the total thickness of the metal functional layers is greater than 30 nm and is in particular between 30 and 60 nm including these values, or even this total thickness is between 35 and 50 nm for a thin film stack with three metal functional layers, or this total thickness is between 40 and 60 nm for a thin film stack with four functional metal layers.
5. Photobioreacteur (1 ) selon l'une quelconque des revendications 1 à5. Photobioreactor (1) according to any one of claims 1 to
4, caractérisé en ce que ledit vitrage de face avant (3) comporte en outre au moins un empilement de couches minces antireflet (12, 13) ne comportant pas de couche fonctionnelle métallique. 4, characterized in that said front face glazing (3) further comprises at least one stack of thin antireflection layers (12, 13) having no metallic functional layer.
6. Photobioreacteur (1 ) selon l'une quelconque des revendications 1 à Photobioreactor (1) according to one of claims 1 to
5, caractérisé en ce que le vitrage de face avant (3) présente une surface extérieure (31 ) texturée par une pluralité de motifs géométriques en relief par rapport au plan général de ladite surface, la surface desdits motifs comprenant chacun au moins deux points tels qu'il existe deux plans sécants entre eux contenant chacun l'un desdits deux points et réunissant les deux conditions suivantes : 5, characterized in that the front face glazing (3) has an outer surface (31) textured by a plurality of geometric patterns in relief with respect to the general plane of said surface, the surface of said patterns each comprising at least two points such as that there are two intersecting planes between them each containing one of said two points and satisfying the two following conditions:
- ces plans sont tous deux perpendiculaires au plan général de la surface texturée, et  these planes are both perpendicular to the general plane of the textured surface, and
- ces plans contiennent chacun l'une des deux droites perpendiculaires à ladite surface et passant par l'un desdits deux points.  these planes each contain one of the two straight lines perpendicular to said surface and passing through one of said two points.
7. Photobioréacteur (1 ) selon l'une quelconque des revendications 1 à Photobioreactor (1) according to one of claims 1 to
6, caractérisé en ce que chaque revêtement antireflet (60, 100, 140) qui est situé au-dessus d'une couche fonctionnelle (40, 80, 120) comporte une couche à base de nitrure de silicium Si3N4 ou à base de nitrure d'aluminium AIN. Characterized in that each antireflection coating (60, 100, 140) which is located above a functional layer (40, 80, 120) comprises a layer based on silicon nitride Si 3 N 4 or based on of aluminum nitride AIN.
8. Utilisation d'un substrat (10) qui est muni d'un empilement de couches minces (10) comportant une alternance de « n » couches fonctionnelles (40, 80, 120) métalliques, notamment de couches fonctionnelles à base d'argent ou d'alliage métallique contenant de l'argent, et de « (n + 1 ) » revêtements antireflet (20, 60, 100, 140), avec n nombre entier > 3, chaque revêtement antireflet comportant au moins une couche antireflet (24, 64, 104, 144), de manière à ce que chaque couche fonctionnelle (40, 80, 120) soit disposée entre deux revêtements antireflet (20, 60, 100, 140), pour réaliser un photobioréacteur (1 ) selon l'une quelconque des revendications 1 à 7.  8. Use of a substrate (10) which is provided with a stack of thin layers (10) comprising an alternation of "n" metal functional layers (40, 80, 120), in particular of silver-based functional layers or metal alloy containing silver, and "(n + 1)" antireflection coatings (20, 60, 100, 140), with n integer> 3, each antireflection coating having at least one antireflection coating (24, 60, 100, 140), , 64, 104, 144), so that each functional layer (40, 80, 120) is arranged between two antireflection coatings (20, 60, 100, 140), for producing a photobioreactor (1) according to one of any of claims 1 to 7.
PCT/FR2012/051655 2011-08-01 2012-07-12 Photobioreactor provided with a selective thin-film multilayer WO2013017763A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR1157031 2011-08-01
FR1157031A FR2978772B1 (en) 2011-08-01 2011-08-01 PHOTOBIOREACTOR PROVIDED WITH A SELECTIVE THIN LAYER STACK.

Publications (1)

Publication Number Publication Date
WO2013017763A1 true WO2013017763A1 (en) 2013-02-07

Family

ID=46614538

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FR2012/051655 WO2013017763A1 (en) 2011-08-01 2012-07-12 Photobioreactor provided with a selective thin-film multilayer

Country Status (2)

Country Link
FR (1) FR2978772B1 (en)
WO (1) WO2013017763A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3089521A1 (en) 2018-12-10 2020-06-12 Commissariat A L'energie Atomique Et Aux Energies Alternatives photobioreactor

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4902081A (en) * 1987-05-22 1990-02-20 Viracon, Inc. Low emissivity, low shading coefficient low reflectance window
WO2003046617A1 (en) 2001-11-28 2003-06-05 Saint-Gobain Glass France Textured transparent plate with high light transmission
US6650478B1 (en) * 1999-08-20 2003-11-18 Cpfilms Inc. Optical filter for a window
WO2006134300A2 (en) 2005-06-16 2006-12-21 Saint-Gobain Glass France Glass pane with light-capturing surface structure
WO2006134301A2 (en) 2005-06-16 2006-12-21 Saint-Gobain Glass France Transparent glass pane provided with a surface structure
WO2007130607A1 (en) * 2006-05-05 2007-11-15 Nanofilm Ltd. Infrared radiation blocking laminate
WO2008033573A2 (en) * 2006-09-13 2008-03-20 Petroalgae, Llc Tubular microbial growth system
WO2010084290A1 (en) 2009-01-23 2010-07-29 Saint-Gobain Glass France Substrate en verre transparent glass substrate and method for producing such a substrate
WO2011034567A2 (en) 2009-09-15 2011-03-24 Bayer Materialscience Llc Photobioreactor for algae growth
WO2011039354A2 (en) 2009-10-01 2011-04-07 Centre National De La Recherche Scientifique (Cnrs) Thin-layer photobioreactor with high volume productivity

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4902081A (en) * 1987-05-22 1990-02-20 Viracon, Inc. Low emissivity, low shading coefficient low reflectance window
US6650478B1 (en) * 1999-08-20 2003-11-18 Cpfilms Inc. Optical filter for a window
WO2003046617A1 (en) 2001-11-28 2003-06-05 Saint-Gobain Glass France Textured transparent plate with high light transmission
WO2006134300A2 (en) 2005-06-16 2006-12-21 Saint-Gobain Glass France Glass pane with light-capturing surface structure
WO2006134301A2 (en) 2005-06-16 2006-12-21 Saint-Gobain Glass France Transparent glass pane provided with a surface structure
WO2007130607A1 (en) * 2006-05-05 2007-11-15 Nanofilm Ltd. Infrared radiation blocking laminate
WO2008033573A2 (en) * 2006-09-13 2008-03-20 Petroalgae, Llc Tubular microbial growth system
WO2010084290A1 (en) 2009-01-23 2010-07-29 Saint-Gobain Glass France Substrate en verre transparent glass substrate and method for producing such a substrate
WO2011034567A2 (en) 2009-09-15 2011-03-24 Bayer Materialscience Llc Photobioreactor for algae growth
WO2011039354A2 (en) 2009-10-01 2011-04-07 Centre National De La Recherche Scientifique (Cnrs) Thin-layer photobioreactor with high volume productivity

Also Published As

Publication number Publication date
FR2978772B1 (en) 2013-08-02
FR2978772A1 (en) 2013-02-08

Similar Documents

Publication Publication Date Title
CA2858182C (en) Substrate provided with a stack having thermal properties and comprising four functional metal films
EP2438024B1 (en) Method for depositing a thin film
EP2661417B1 (en) Substrate provided with a stack having thermal properties, in particular for manufacturing heated glass
EP2379463B1 (en) Substrate provided with a multilayer stack having thermal properties and an absorbent layer
FR2998564A1 (en) SUBSTRATE WITH PARTIALLY METALLIC LAYER STACK, GLAZING, USE AND METHOD.
EP2379464A1 (en) Substrate provided with a multilayer stack having thermal properties and absorbent layers
EP2268588A2 (en) Substrate comprising a stack with thermal properties
CA2949804A1 (en) Substrate equipped with a multilayer comprising a partial metal film, glazing unit and process
CA2949809A1 (en) Substrate equipped with a multilayer comprising partial metal films, glazing unit, use and process
WO2013017763A1 (en) Photobioreactor provided with a selective thin-film multilayer
EP3201150B1 (en) Substrate provided with a multilayer having thermal properties and a substoichiometric intermediate layer
FR2924232A1 (en) SUBSTRATE EQUIPPED WITH A THERMAL PROPERTY STACK
WO2016051066A1 (en) Substrate provided with a stack having thermal properties and an intermediate layer of stoichiometric compounds
CA2949805A1 (en) Substrate equipped with a multilayer comprising a partial metal film, glazing unit, use and process
FR2924231A1 (en) SUBSTRATE PROVIDED WITH A STACK WITH THERMAL PROPERTIES
EP3383812A1 (en) Susbtrate provided with a stack having thermal properties, comprising at least one nickel oxide layer
CA3006339A1 (en) Susbtrate provided with a stack having thermal properties, comprising at least one nickel oxide layer

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12743506

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12743506

Country of ref document: EP

Kind code of ref document: A1