WO2017132122A1

WO2017132122A1 - Fluid useful as coolant containing carbon nanoparticles and dispersed semi-crystalline polymer particles

Info

Publication number: WO2017132122A1
Application number: PCT/US2017/014692
Authority: WO
Inventors: Michael T. Malanga; Peter J. Cate; Daniel L. Dermody; Lalitha V. GANAPATIBHOTIA
Original assignee: Dow Global Technologies Llc
Priority date: 2016-01-28
Filing date: 2017-01-24
Publication date: 2017-08-03

Abstract

Discloses are compositions comprising polar liquids containing carbon nanoparticles and dispersed semi-crystalline polymer particles. Also disclosed are methods of preparing the compositions and using the compositions to cool systems that generate heat.

Description

FLUID USEFUL AS COOLANT CONTAINING CARBON NANOPARTICLES AND DISPERSED SEM I-CRYSTALLINE POLYM ER PARTICLES

FIELD

[001 ] The present invention relates to compositions comprising polar liquids containing carbon nanoparticles and dispersed semi-crystalline polymer particles. The present invention also relates to methods of preparing the compositions and using the compositions to cool systems that generate heat.

BACKGROUND

[002] Many sophisticated mechanical systems are powered by a motor or engine. In operation motors and engines generate heat and if the heat is not dissipated the engines or motors operation lifetime may be compromised. Coolant systems have been developed that include coolant fluids and sections that cool the coolant fluid, such as radiators in engine systems. In many systems the coolant fluids are passed through or along certain portions of the engines or motors to absorb some of the heat generated and then to a cooling section to remove a portion of the heat from the coolant fluid. In many cases the coolant flows through a closed loop system that continuously flows coolant liquid through or along the engine or motor and through the cooling section during operation of the system. The engines or motors can include combustion chambers or fuel cells and battery systems that generate heat in operation.

[003] There is a need to improve the fuel efficiency of many engine or motor systems while reducing the emissions generated by the engine or motor. For instance, in automobiles turbocharged 4 and 6 cylinder engines are replacing larger 6 and 8 cylinder engines. These newer engines generate higher temperatures and create higher temperature hot spots than the engines they replace. These newer engines have not provided as much of an increase in fuel efficiency as the increase in power output because the engine settings cannot be optimized due to higher temperatures in the combustion chamber causing pre-ignition knock so the spark must be retarded, which negatively impacts maximum brake torque and thereby fuel efficiency. In addition, radiator capacities, and thus size and weight, have been increased to deal with the higher temperatures generated by these engines. This increases the weight of the vehicle which also negatively effects fuel efficiency. There are also concerns that continued exposure of coolant fluids to higher temperatures may result in faster degradation of components of the coolant fluid and higher operating costs due to the need to replace the coolants more frequently. The degradation components of the current coolants are also known to increase the rate of corrosion in current engine and radiator materials such as steel and aluminum. Coolant fluids also aid in warming up engine systems such that the systems run more efficiently, engines in the warmup phase generate higher undesirable emissions and there is a need to improve the rate of warmup to further reduce emissions generated by engine systems. Coolants that have the ability to speed up the warmup time can help reduce emissions generated. Coolants that require lower flow rates are desired to allow the utilization of smaller and lighter pumps.

[004] There are a number of technical requirements for coolant systems in order for the systems to be commercially acceptable. The systems must have a suitable viscosity for efficient pumping which does not require larger pumping systems or require greater power draw (parasitic losses). The systems must be formulated to prevent corrosion of the materials in contact with the fluids and be reasonably durable to avoid frequent change out of the fluids.

[005] There have been a number of systems developed to address these problems, see for example, Zhiqiang US 7348298 disclosing the use of carbon nanoparticles in a fluid developed for use as a heat transfer fluid; Haiping US 2007/0158610 disclosing a coolant including carbon nanoparticles; Barreto US 2013/0341556 discloses heat exchange fluids containing dispersions of polymers, all incorporated herein by reference in their entirety. None of the disclosed systems address all of the needs identified.

[006] Thus, what is needed is a coolant fluid with rapid transfer of heat within the fluid, high heat capacity, greater heat absorbing capability, the ability to rapidly cool hot spots within a system, long term durability, relatively low viscosities and good corrosion inhibition. What are also needed are methods for the preparation of such fluids. What are needed are methods of using coolant fluids that allow for the reduction in size and weight of coolant systems, that facilitate faster engine warm-up, and which can cool engines and motors at reduced liquid flow rates.

SUMMARY

[007] The present disclosure relates to compositions comprising: a) one or more polar liquids; b) one or more chemically functionalized carbon nanoparticles; and c) particles of one or more semi-crystalline polymers having a melting point of from about 60 °C to about 180 °C dispersed in the one or more polar liquids; wherein the composition exhibits thermal conductivity of about 0.20 W/mK or greater, about 0.40 W/mK or greater, or about 0.60 W/mK or greater and a total heat capacity of about 3400 J/Kg*K or greater. The particles of the one or more semi-crystalline polymers may have a latent heat of greater than about 20,000 J/Kg. The semi-crystalline polymers may exhibit a heat of fusion of about 20.0 J/g or greater. The semi-crystalline polymers themselves may have a total heat of fusion as measured by DSC or other methods of from about 20 to about 400 J/g. The one or more semi-crystalline polymers having a melting point of from about 80 °C to about 180 °C may be one or more polyolefins, one or more polyesters, one or more polyamides, one or more polystyrenes, or the like, or mixtures thereof. The one or more semi-crystalline polymers having a melting point of from about 80 °C to about 180 °C may be one or more polyolefins. The carbon nanoparticles may be functionalized to have one or more of carbonyl (CO), carbonyloxy (COO), hydroxyl (OH), amines (secondary NH or primary NH₂) ureas, amides or aminoalcohol groups on their surface. The compositions may include one or more dispersants capable of stabilizing the one or more carbon nanoparticles or the one or more semi-crystalline polymers in the one or more polar liquids. The polar fluid may include one or more known materials which are liquid at room temperature or one or more materials that are liquid at temperatures down to -50 °F (-45 °C) or at temperatures up to 150 °F (65.5 °C) that are polar in nature. These polar liquids may include water, ethylene glycol, propylene glycol, other glycols, methyl alcohol or other alkyl alcohols, phenols, or the like or mixtures of any of these polar liquids. The compositions may include one or more corrosion inhibitors. The compositions may include one or more nucleating agents capable of aiding the crystallization of the one or more semi-crystalline polymers. The compositions may include one or more antifoaming agents. The compositions may include one or more wetting agents, surfactants or other additives that reduce surface tension and improve contact of the fluid with the metal surfaces that are being cooled by the fluid (or heated in the case of the radiator). The carbon nanoparticles may be dispersed in the polar liquid, and/or dispersed in the particles of one or more semi-crystalline polymers, and/or located on the surface of the particles of one or more semi-crystalline polymers or any combination thereof. The polar liquid may comprise one or more of water, a polyol, a solution of a salt in water, or a mixture thereof. Dyes or other means of coloring the fluid may also be included to distinguish this fluid.

[008] Disclosed is a method comprising a) contacting a composition disclosed herein with a system that generates heat; b) transporting the composition from the system that generates the heat; and c) contacting the composition with a system that cools the composition. The composition may be continuously moved to contact the system that generates heat and the cooling system in sequence during operation. The system that generates heat may be an engine and the cooling system may be a radiator. The system that generates heat may reach temperatures from about 120 °C to about 180 °C and the cooling system may cool the composition from about 60 °C to about 120 °C. The particles of one or more semi-crystalline polymers may at least partially melt in contact with the system that generates the heat and the one or more semi-crystalline polymers may crystallize when in contact with the cooling system.

[009] Disclosed are methods for preparing a composition disclosed herein comprising: a) preparing the dispersion of particles of one or more semi-crystalline polymers in one or more polar liquids; and b) contacting the functionalized carbon nanoparticles with the one or more semi-crystalline polymers or with the dispersion of particles of one or more semi- crystalline polymers in one or more polar liquids. The functionalized carbon nanoparticles may be dispersed in one or more polar liquids and the dispersion containing the functionalized carbon nanoparticles may be contacted with the dispersion of particles of one or more semi- crystalline polymers in one or more polar liquids; the functionalized carbon nanoparticles are contacted with the one or more semi-crystalline polymers by adding them to the polar liquids while forming the particles of the one or more semi-crystalline polymers; the functionalized carbon nanoparticles may be contacted with the dispersion of particles of one or more semi- crystalline polymers; or any combination thereof. The one or more polar liquids may be added after contacting the functionalized carbon nanoparticles with the one or more semi-crystalline polymers or with the dispersion of particles of one or more semi-crystalline polymers in one or more polar liquids.

[0010] The compositions disclosed exhibit high heat capacities, the heat capacities may be about 3400 J/Kg*K or greater. In addition the compositions disclosed may have additional ability to absorb heat energy through the melting of the semi-crystalline polymeric phase. In the temperature region of melting this polymer phase could have 1000 J/Kg*K additional heat absorbance due to the melting (latent heat) available. This could provide a total of 4400 J/Kg heat absorbance or greater in the temperature region associated with the melting of the polymer phase. The heat capacity and heat of fusion of this composition can be measured by anyone knowledgeable in the art using DSC techniques. Additionally, the compositions disclosed exhibit high thermal conductivities and high heat transfer capabilities. The addition of the carbon nanoparticles provide thermal conductivity to the composition disclosed. As measured using well known techniques such as a transient hot wire test the disclosed fluids may have thermal conductivity about 0.20 W/mK or greater and as high as about 1.5 W/mK. The thermal conductivity may be about 0.30 W/mK or greater, about 0.4 W/mK or greater or about 0.60 W/mK or greater. The disclosed fluid may exhibit an overall heat transfer coefficient of about 5,000 W/m²K or greater, or about 30,000 W/m²K or greater as measured and calculated according to the method described in reference ICES2012-81134, R. Ehid et al. The compositions disclosed exhibit viscosities which allow the use of lower capacity and size pumps. The viscosity of the coolant fluids disclosed may be about 100 cP or less as measured using a kinematic tube according to ASTM E1269-11 (0/ +100 °C) or about 25 cP or less. The compositions exhibit excellent dispersion stability and corrosion inhibition. The compositions exhibit corrosion properties as measured according to ASTM D1384/D2570/D4340 and a mg weight loss of 30 mg or less or 5 mg or less. The compositions disclosed demonstrate good compatibility with corrosion inhibitors commonly used in cooling fluids. The compositions exhibit compatibility with common inhibitors according to ASTM D4340 that is a loss of about 1.0 or less mg/cm²/wk or less or about 0 mg/cm²/wk. The compositions disclosed allow the utilization of smaller pumps and air side or liquid side cooling systems, adjustment of engine operating conditions to optimize fuel efficiency and to shorten engine warm-up times with a resulting reduction in engine emissions. The compositions disclosed may allow for lesser amounts of coolant or a smaller coolant system with less weight providing for greater fuel economy of the engine and vehicle it is installed in.

DESCRIPTION OF THE DRAWINGS

[001 1] Figure 1 is the DSC of the semi-crystalline polymer mixture used to prepare the inventive example 2 which has first been dried to remove all water before testing.

[0012] Figure 2 is a DSC of inventive example 2 fluid as described in Table 1 with the heat capacity in J/gK and the melting endotherm (near 128 °C) of the polymeric additive.

DETAILED DESCRIPTION

[0013] The explanations and illustrations presented herein are intended to acquaint others skilled in the art with the invention, its principles, and its practical application. Accordingly, the specific embodiments of the present invention as set forth are not intended as being exhaustive or limiting of the invention. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are incorporated by reference for all purposes. Other combinations are also possible as will be gleaned from the following claims, which are also hereby incorporated by reference into this written description.

[0014] Disclosed is a composition useful as a cooling fluid comprising: a) one or more polar liquids; b) one or more functionalized carbon nanoparticles; and c) particles of one or more semi-crystalline polymers having a melting point from about 80 °C to about 180 °C dispersed in the one or more polar liquids.

[0015] The compositions disclosed herein may further comprise any one or more of the features described in this specification in any combination, including the preferences and examples listed in this specification, and includes the following features: the one or more semi- crystalline polymers having a melting point from about 80 °C to about 180 °C comprise one or more polyolefins, one or more polyesters, one or more polyamides, one or more polystyrenes, or mixtures thereof; the one or more semi-crystalline polymers having a melting point and recrystallization point from about 80 °C to about 180 °C comprise one or more polyolefins; the carbon nanoparticles are functionalized to have one or more carbonyl (CO), carbonyloxy (COO), hydroxyl (OH), amines (secondary NH or primary NH2) ureas, amides or aminoalcohol groups on their surface; the carbon nanoparticles have a variety of particle sizes and shapes from spheroid to ovoid to plate like or other shapes; the particles exhibit a distribution of sizes of from about 1 nm to about 100 nm in at least one direction; the carbon nanoparticle plate like structures may be about 1 nm to about 100 nm in thickness and about 2 microns to about 50 microns in diameter; the particle size of the semi-crystalline polymers is about 0.2 microns to about 10 microns; the one or more semi-crystalline polymers exhibit a melting point within the range of about 100 °C to about 160 °C; the carbon nanoparticles are functionalized to have alcohol groups on their surface through the reaction of aminoalcohols with COOH groups on the edges and surfaces of the carbon nanoparticles; the carbon nanoparticles are one or more of graphene, graphene oxide, single gra-phene or graphene oxide sheets or stacks of graphene or graphene oxide sheets, reduced graphene oxide sheets, graphite, single-walled carbon nanotubes, multi-walled carbon nano-tubes, carbon nanodiamonds, carbon nanoribbons, and fullerenes; the carbon nanoparticles are one or more graphene based compositions; the composition includes one or more dispersants capable of stabilizing the one or more carbon nanoparticles or the one or more semi-crystalline polymers in the one or more polar liquids; the compositions may include one or more antifoaming agents; the compositions may include one or more wetting agents, surfactants or other additives that reduce surface tension and improve contact of the fluid with the metal surfaces that are being cooled; the compositions may also include dyes or other additives to adjust the color of the fluid to aid in identification; the compositions may include ultraviolet light sensitive additives that will aid in detecting leaks in a sealed coolant system; the particles of one or more semi-crystalline polymers comprise one or more homopolymers or copolymers containing ethylene or propylene monomer units; the particles of one or more semi-crystalline polymers comprise one or more polyolefins and contain a polyolefin having grafted to the backbone maleic anhydride or a hydrolysis product thereof; the compositions may comprise a nucleating agent capable of aiding the crystallization of the one or more polymers; one or more corrosion inhibitors; a) the one or more polar liquids are present in an amount of about 50 to 99 percent by weight, b) the one or more functionalized carbon nanoparticles are present in an amount of about 0.001 to about 10 percent by weight, and, c) the particles of one or more semi- crystalline polymers dispersed in the one or more polar liquids are present in an amount of about 0.5 to about 10 percent by weight, wherein the percent by weights are based on the weight of the composition; the carbon nanoparticles are dispersed in the polar liquid, dispersed in the particles of one or more semi-crystalline polymers, located on the surface of the particles of one or more semi-crystalline polymers or any combination thereof; the polar liquid comprises one or more of water, a glycol, a polyglycol, a solution of a salt in water, or a mixture thereof; and the polar liquid comprises a mixture of water and polyol.

[0016] The method of using the compositions disclosed herein may further comprise any one or more of the features described in this specification in any combination, including the preferences and examples listed in this specification, and includes the following features: the composition is continuously moved to contact the system that generates heat and the cooling system in sequence during operation; the system that generates heat is an engine and the cooling system is a radiator; the system that generates heat reaches temperatures of from about 120 °C to about 180 °C and the cooling system cools the composition to about 60 °C to about 120 °C; and the particles of one or more semi-crystalline polymers at least partially melt in contact with the system that generates the heat and the one or more semi-crystalline polymers crystallize when in contact with the cooling system.

[0017] The method of preparing the compositions disclosed herein may further comprise any one or more of the features described in this specification in any combination, including the preferences and examples listed in this specification, and includes the following features: the functionalized carbon nanoparticles are dispersed in one or more polar liquids and contacted with the dispersion of particles of one or more semi-crystalline polymers in one or more polar liquids; the functionalized carbon nanoparticles are contacted with the one or more semi-crystalline polymers by adding them to the polar liquids while forming the particles of the one or more semi-crystalline polymers; the functionalized carbon nanoparticles are contacted with the dispersion of particles of one or more semi-crystalline polymers; or any combination thereof; and the one or more polar liquids are added after contacting the functionalized carbon nanoparticles with the one or more semi-crystalline polymers or with the dispersion of particles of one or more semi-crystalline polymers in one or more polar liquids.

[0018] One or more as used herein means that at least one, or more than one, of the recited components may be used as disclosed. The term "carbon nanomaterial" refers to a nanomaterial, carbon nanoparticles, which contains primarily carbon, for example, nanodiamond, graphite, fullerenes, carbon nanotubes, carbon fibers, and combinations thereof. Alkanolamine refers to a hydrocarbon containing both a hydroxyl group and an amine group each attached to separate carbons.

[0019] The compositions contain a polar liquid which functions to disperse the other components of the compositions and which have a sufficient heat capacity to serve as a coolant liquid for cooling systems. The polar liquid may be one or more polar liquids useful in coolant liquids. Exemplary polar liquids include water, alcohols, glycols, polyglycols, a solution of a salt in water, and mixtures thereof. Exemplary polar liquids comprise water in admixture with a compound that depresses or lowers the freezing point of the mixture. Compounds that depress the freezing point of the mixtures may comprise one or more of alcohols, glycols, polyglycols, salts or mixtures thereof. Glycols comprise a carbon backbone having two or more terminal groups selected from hydroxyl groups and ether groups. Polyglycols are compounds comprising two or more glycol units where the glycol units are linked through an oxygen atom. The carbon backbones may be straight or branched. Exemplary glycol units comprise ethylene, propylene, butylene and mixtures thereof. The glycol units may be ethylene. The glycol units may be propylene. Polyglycols comprise multiple glycols linked in a chain and may be polyethylene glycols, polypropylene glycols, or polybutylene glycols. Exemplary glycols include ethylene glycol, propylene glycol, glycerol, sorbitol, 1 ,2,6 hexanetrio!, trimethyioipropane and the like. Exemplary polyglycols comprise diethylene glycol, dipropylene glycol, Methylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol dipropylene glycol, tripropyiene glycol, tetrapropylene glycol pentapropy!ene glycol, hexapropylene, and the like. The glycols or polyg!ycois may have one or more of the hydroxy! groups replaced with a hydrocarbyl group. The hydrocarbyi groups may be straight or branched chain aikyi groups, cyclic or heterocyclic groups. The straight or branched chain groups may be methyl, ethyl, propyl or butyl. Exemplary glycols or poiyglycols which have one or more of the hydroxy! groups replaced with a hydrocarbyl groups include ethoxy!ated furfuryi. dimethyl ether of glycerol, methoxyethanoi, and the like. Exemplary alcohols include methanol, ethanol, propanol, butano!, furfural, tetrahydrofurfury!, and glycerin. Exemplary classes of salts include alkali metal salts for example sodium or potassium propionate, salts of organic acids, and the like. Exemplary salts include acetic acid, propionic acid, succinic acid, betaine and mixtures thereof.

[0020] The polar liquid may comprise water and another component which adjusts the freezing point or boiling point of the polar liquid (modifier). The component which adjusts the freezing point or boiling point of the polar liquid and the amount thereof may be chosen to function properly in a region to fit the weather conditions in that region. For example in regions that experience extreme cold higher the amounts of the modifiers may be higher and the particular modifier may be chosen to reduce the freezing point to match the expected temperature of the region. In regions that experience high temperatures the polar liquid may be modified to use lower amounts of modifiers or modifiers with higher boiling points. Polar liquids that contain water may contain water in a sufficient amount to allow the composition disclosed to function in the region for which it is formulated, for example the composition does not freeze or boil under expected conditions. Water may be present in an amount of about 20 percent by weight or greater of the polar liquid, about 30 percent by weight or greater, or about 40 percent by weight or greater. Water may be present in an amount of about 90 percent by weight or less of the polar liquid, about 70 percent by weight or less, or about 60 percent by weight or less. Polar liquids that contain water may contain modifiers in a sufficient amount to allow the composition disclosed to function in the region for which it is formulated, for example the composition does not freeze or boil under expected conditions. Modifiers may be present in an amount of about 10 percent by weight or greater of the polar liquid, about 30 percent by weight or greater, or about 40 percent by weight or greater. Modifiers may be present in an amount of about 80 percent by weight or less of the polar liquid, about 70 percent by weight or less, or about 60 percent by weight or less. These modifiers may be present at 50 percent by weight. Where the modifier is a salt the salt may be present in the polar liquid in an amount of about 10 percent by weight or greater of the polar liquid, about 30 percent by weight or greater or about 50 percent by weight or greater. Where the modifier is a salt the salt may be present in the polar liquid in an amount of about 80 percent by weight or less of the polar liquid, about 70 percent by weight or less, or about 60 percent by weight or less.

[0021] The polar liquid may be present in the compositions disclosed herein in sufficient amount such that the composition exhibits a viscosity that allows the composition to function efficiently in a cooling system and which has the desired heat capacity. Polar liquid may be a water and glycol mixture for example where the glycol component is present in an amount of , about 20 percent by weight or greater of the compositions disclosed herein, about 40 percent by weight or greater or about 50 percent by weight or greater. Polar liquid may be present in an amount of about 99 percent by weight or less of the compositions disclosed herein, about 80 percent by weight or less, or about 60 percent by weight or less.

[0022] The composition disclosed contains one or more semi-crystalline polymers dispersed in the polar liquid. The semi-crystalline polymers may comprise any polymer that has some crystallinity and which melts in the temperature region of a system that generates heat and which cools in the temperature region of the cooling system of the system that generates heat. The semi-crystalline polymer may comprise a polymer that is capable of forming particles upon exposure to temperatures near its melting temperature, which can withstand the conditions of the system which it cools and contributes to the viscosity of the composition in a manner such that the desired viscosity is achieved. The semi-crystalline polymers may exhibit a peak melting point of 80 °C or greater, about 100 °C or greater, about 120 °C or greater, or about 130 °C or greater. The semi-crystalline polymers may exhibit a peak melting point of about 180 °C or less, about 160 °C or less or about 140°C or less. The semi-crystalline polymers may exhibit a recrystallization temperature of about 60 °C or greater, about 80 °C or greater or about 110 °C or greater. The semi-crystalline polymers may exhibit a recrystallization temperature of about 130 °C or less or about 120 °C or less. The semi- crystalline polymers may comprise any polymers that can be dispersed in the polar liquid, exhibit the desired melting temperatures, recrystallization temperatures, viscosity properties and can withstand the conditions they are exposed to in a cooling system. Exemplary polymer systems include polymers containing one or more polyolefins, polyesters, polyamides, polystyrenes, blends thereof or copolymers containing more than one unit of such copolymers. The semi-crystalline polymers may be used in the form of particles dispersed in a polar liquid including water or a mixture of water and glycol. The particles may be of any size that provides a composition of the desired viscosity and heat capacity. As used herein particle size is the volume-mean particle size. Particle size may be measured by laser diffraction techniques. Particle size refers to the diameter of the polymers in the dispersion. For polymer particles that are not spherical, the diameter of the particle is the average of the long and short axis of the particle. Particle sizes can be measured on a Beckman-Coulter LS230 laser-diffraction particle size analyzer. The size of the particles may be about 0.2 microns or greater, about 0.5 microns or greater and about 1.0 microns or greater. The size of the particles may be about 10 microns or less, about 5 microns or less and about 2 microns or less. The semi-crystalline polymers may comprise one or more polyolefins, for example polyolefins as disclosed in Moncla et al. US 7,803,865; Moncla et al. US 7,947,776; and Van Sumeren, et al. US 8,916,640 incorporated herein by reference in their entirety for all purposes. The polyolefins may comprise polyethylene, polypropylene, copolymers of ethylene and propylene, copolymers of ethylene and/or polypropylene with one or more C 4 to 8 alpha olefins. The polyolefins may comprise blends of two or more polyolefins. The polyolefins may include one or more polyolefins with pendant carboxylic acids or esters thereto. The polyolefins may comprise one or more polyolefins having pendant maleic anhydride groups or hydrolysis products thereof. The particles of the semi-crystalline polymers may be present in the compositions in a sufficient amount to provide the desired heat absorbing capacity via the polymers heat of fusion (latent heat) of melting and desired viscosity. The semi-crystalline polymers will have a total heat of fusion (latent heat) as measured using common methods such as differential scanning calorimetry (DSC) of about 20 KJ/g or greater and about 120KJ/g or less depending on the type of polymer and the level of total crystallinity. The semi-crystalline polymers may be present in an amount of about 0.5 percent by weight of the composition or greater, about 1 percent by weight or greater, or about 2 percent by weight or greater. The semi-crystalline polymers may be present in an amount of about 10.0 percent by weight of the composition or less, or about 5 percent by weight or less.

[0023] The one or more polyolefins may comprise one or more copolymers of polypropylene and an alpha olefin. The one or more polyolefins may be one or more polyolefin copolymers having pendant carboxylic acid groups, for instance copolymers of ethylene acrylic acid. The one or more polyolefins may comprise one or more high melt flow rate polypropylene homopolymers. The one or more polyolefins may include one or more polyolefins with maleic anhydride, or a hydrolysis product thereof, grafted to the backbone. The one or more polyolefins may include one or more polyolefins with maleic anhydride, or a hydrolysis product thereof, grafted to the backbone; one or more copolymers of polypropylene and an alpha olefin; one or more polyolefin copolymers having pendant carboxylic acid groups; and one or more high melt flow rate polypropylene homopolymers.

[0024] A polyolefin is a polymer prepared by polymerization of unsaturated groups of one or more compounds having a straight or branched hydrocarbon chain. The compounds having a straight or branched hydrocarbon chains comprise ethylene, propylene, 1-butene, 3 -methyl- 1-butene, 4-methyl-i- pentene, 3-metbyM- peniene, 1-heptene, 1-hexene, 1-octene, 1-decene, and 1- dodecene. The polyolefins useful can be homopolymers or copolymers of more than one compounds having a straight or branched hydrocarbon chain. The polyolefins may comprise elastomers and blends of olefin polymers. Exemplary polyolefins include polyethylene, polypropylene, poly- 1-butene, poly-3-metbyl- 1-butene, poly-3-methy!- 1-pentene, poiy-4-methyi-!-pentene, ethylene-propylene copolymers, ethylene- 1-butene copolymers, and propylene- 1-butene copolymers, copolymers {including elastomers) of an alpha-olefin with a conjugated or non-conjugated diene, as typically represented by ethylene- butadiene copolymers and ethylene-ethylidene norbornene copolymers; and polyolefins (including elastomers) such as copolymers of two or more alpha-olefins with a conjugated or non-conjugated diene, as typically represented by ethy!ene-propyiene-butadiene copolymers, ethylene-propylene-dicyclopentadiene copolymers, ethylene-propylene- 1 ,5 -hexadiene copolymers, and ethylene-propylene-ethylidene norbornene copolymers; ethylene-vinyl compound copolymers such as ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, ethylene-vinyl chloride copolymers, ethylene acrylic acid or ethylene- (meth)acryiic acid copolymers, and ethylene (meth)aerylate copolymers. Exemplary polyolefins include ethylene-based polymers, propylene-based polymers, propylene-ethylene copolymers, ethylene-alpha olefin copolymers or propylene-alpha olefin copolymers, ethylene-propylene-diene terpolymers. Olefinic polymers include homogeneous polymers, as described in U.S. Pat. No. 3,645,992 issued to Elston; high density polyethylene (HDPE), as described in U.S. Pat. No. 4,076,698 issued to Anderson; heterogeneously branched linear low density polyethylene (LLDPE); heterogeneously branched ultra-low linear density polyethylene (ULDPE); homogeneously branched, linear ethylene/alpha-olefin copolymers; homogeneously branched, substantially linear ethylene/alpha-olefin polymers, which can be prepared, for example, by processes disclosed in U.S. Pat. Nos. 5,272,236 and 5,278,272, the disclosures of which are incorporated herein by reference; and high pressure, free radical polymerized ethylene polymers and copolymers such as low density polyethylene (LDPE) or ethylene vinyl acetate polymers (EVA). The polyolefin may be a propylene-based copolymer or interpolymer. One embodiment of the propylene-based polymers is a propylene-ethylene copolymer or interpolymer, where ethylene may be present in an amount from about 5% to about 25% by weight. Propylene-rich alpha-olefin interpolymers may have from 5 to 25% by weight of ethylene-derived units and 95 to 75% by weight of propylene-derived units. The polyolefin may comprise an alpha-olefin interpolymer of ethylene with a comonomer comprising an alkene, such as 1- octene. The ethylene and octene copolymer may be present alone or in combination with another polyolefin resin. When present together, the weight ratio between the ethylene and octene copolymer and another polymer may range from about 1 : 10 to about 10: 1 , such as from about 3:2 to about 2:3. The polyolefin resin, such as the ethylene- octene copolymer, may have a crystallinity of less than about 50%, the crystallinity of the polyolefin may range from 5 to 35 percent. [0025] The polyolefins may be functionalized by incorporating at least one functional group in its polymer structure. Exemplary functional groups may include carboxylic acids or structures that form carboxylic acids upon hydrolysis in water, for example maleic anhydride. Ethylenically unsaturated compounds that can introduce such functional groups into the backbone of the polyolefins include ethylenically unsaturated mono- and di-functional carboxylic acids, ethylenically unsaturated mono- and di-functional carboxylic acid anhydrides, salts thereof and esters thereof. Such functional groups may be grafted to an olefin polymer, or it may be copolymerized with an olefin, such as ethylene or propylene, and an optional additional comonomer to form an interpolymer of olefin, the functional comonomer and optionally other comonomer(s). Means for grafting functional groups onto polyolefins are described for example in U.S. Patents Nos. 4,762,890, 4,927,888, and 4,950,541 , the disclosures of which are incorporated herein by reference in their entirety. One particularly useful functional group is maleic anhydride. The amount of the functional group present in the functional polymer may vary and is chosen to enhance the final properties of the composition of the invention. The functional group may be present in an amount of about 0.25 weight percent or more in some embodiments; about 5 weight percent or more in other embodiments; and about 7 weight percent or more based on the weight of the polyolefins present. The functional group may be present in an amount of about 40 weight percent or less; about 30 weight percent or less or about 25 weight percent or less, based on the weight of the polyolefins present. The polyolefins comprise one or more non-polar polyolefins. The polyolefins may comprise one or more non-polar polyolefins and one or more functionalized polyolefins.

[0026] The composition includes one or more functionalized carbon nanoparticles which enhance the transmission of heat through the composition. The one or more functionalized carbon nanoparticles have a size and morphology which enhances the efficient transfer of heat through the composition. The one or more functionalized carbon nanoparticles may exhibit a mean length in a least one direction of about 1 nm or greater, or about 20 nm or greater. The one or more functionalized carbon nanoparticles may exhibit a mean length in a least one direction of about 50 microns or less, about 5 microns or less, or about 5 to about 25 microns. The one or more functionalized carbon nanoparticles may exhibit aspect ratio of about 1 or greater, about 10 or greater, or about 1000 or greater. The one or more functionalized carbon nanoparticles may exhibit an aspect ratio of about 1000 or less, about 100 or less, or about 10 or less. The one or more carbon nanoparticles may exhibit a thermal conductivity of about 1000 W/mK or greater, about 3000 W/mK or greater or about 6000 W/mK or greater. The carbon nanoparticles may be a one, two, or three dimensional material, as is known in the art. The carbon nanoparticles may be one or more of graphene, graphene oxide, single graphene or graphene oxide sheets or stacks of graphene or graphene oxide sheets, graphite, single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon nanodiamonds, carbon nanoribbons, fullerenes, or other known carbon nanoparticles. The carbon nanoparticles are functionalized with functional groups on the surface which enhance dispersion of the carbon nanoparticles in the polar liquid. Functionalized carbon nanoparticles may contain one or more carbonyl (CO), carbonyloxy (COO), hydroxyl (OH), amines (secondary NH or primary NH2) ureas, amides or aminoalcohol groups on their surface. Functionalized carbon nanoparticles may contain aminoalcohol groups on their surface. Aminoalcohol refers to a hydrocarbyl group containing both a hydroxyl group and an amine group each attached to separate carbons. The aminoalcohol may be a primary, secondary, or tertiary amine and may be derived from a linear, branched, cyclic, aliphatic alkanolamine or aromatic alkanolamine.

[0027] The one or more functionalized carbon nanoparticles are dispersed in the polar liquid either directly or in contact with the particles of semi-crystalline polymers. Where the one or more functionalized carbon nanoparticles are dispersed in the polar liquid in contact with the particles of semi-crystalline polymers, the particles may be dispersed through-out the particles (embedded in the particles) or supported on the surface of the particles. The functionalized carbon nanoparticles may be present in the composition in a location and an amount which enhances the flow of heat through the composition and which allows the composition to exhibit the desired viscosity. The functionalized carbon nanoparticles may be present in the composition in an amount of about 0.01 percent by weight of the composition or greater, about 1 percent by weight or greater, or about 2 percent by weight or greater. The functionalized carbon nanoparticles may be present in the composition in an amount of about 10.0 percent by weight of the composition or less, about 5.0 percent by weight or less, or about 3 percent by weight or less.

[0028] The compositions may include dispersants for the functionalized carbon nanoparticles where the nanoparticles are dispersed directly in the polar liquid. Any dispersant that can disperse the functionalized carbon nanoparticles may be utilized. Exemplary dispersants for the functionalized carbon nanoparticles are dispersants having a high HLB value, for example about 10 or less, and include nonylphenoxypoly(ethyleneoxy) ethanol based surfactants, and the like. The dispersant for the functionalized carbon nanoparticles may be present in an amount of about 1 percent by weight or greater of the compositions, about 3 percent by weight or greater, or about 5 percent by weight or greater. The dispersant for the functionalized carbon nanoparticles may be present in an amount of about 5 percent by weight or less of the compositions, about 3 percent by weight or less, or about 2 percent by weight or less.

[0029] The compositions may further comprise dispersants for the semi-crystalline polymer particles. Any dispersant which disperses the semi-crystalline polymer particles in the polar liquid and which does not negatively impact the function of the compositions may be utilized. Dispersants that may be used include long chain fatty acids or fatty acid salts having from 12 to 60 carbon atoms or from 12 to 40 carbon atoms. The salts may be alkali metal or ammonium salts of the fatty acid, prepared by neutralization of the acid with the corresponding base, e.g., NaOH, KOH, NH₄OH, and amines, such as ethanol amine, triethanol amine, and the like. These salts may be formed in situ in the dispersion step, as described more fully below. Other exemplary dispersants include cationic surfactants, anionic surfactants, or a non- ionic surfactants. Examples of anionic surfactants include sulfonates, carboxylates, and phosphates. Examples of cationic surfactants include quaternary amines. Examples of non- ionic surfactants include block copolymers containing ethylene oxide and silicone surfactants. Surfactants useful maybe either external surfactants or internal surfactants. External surfactants are surfactants that do not become chemically reacted into the polymer during dispersion preparation. Examples of external surfactants useful herein include salts of dodecyl benzene sulfonic acid and lauryl sulfonic acid salt. Internal surfactants are surfactants that do become chemically reacted into the polymer during dispersion preparation. An example of an internal surfactant useful herein includes 2,2-dimethylol propionic acid and its salts. The dispersant for the semi-crystalline polymers may be present in an amount of about 1 percent by weight or greater of the compositions, about 2.5 percent by weight or greater, or about 5 percent by weight or greater. The dispersant for the semi-crystalline polymers may be present in an amount of about 10.0 percent by weight or less of the compositions, about 8 percent by weight or less, or about 6 percent by weight or less.

[0030] The composition may further include corrosion inhibitors that inhibit corrosion of aluminum and ferrous metals. Exemplary classed of corrosion inhibitors include one or more of silicates, carboxylates, phosphates, borates, molybdates, nitrates, nitrites or the alkali metal, alkaline earth metal, ammonium or amine salts thereof. Exemplary carboxylates include saturated and unsaturated aliphatic, and aromatic mono-, di- and tricarboyxlic acids, and salts and isomers thereof, and any mixture thereof. The carboxylates include C₄ to C;2 mono-, or di-carboxylic acids, such as 2-ethyi hexanoic acid, neodecanoic acid, benzoic acid, t-butylbenzoic acid, dodecanediodic acid and sebacic acid, or alkali and alkali earth metal, ammonium and amine salts, or isomers and mixtures thereof. The corrosion inhibitors may be present in the compositions in an amount of greater than about 0 percent by weight based on the weight of the coolant composition or about 0,05 percent by weight or greater. The corrosion inhibitors may be present in the compositions in an amount of to about 7 percent by weight or less, or about 6 percent by weight or less, based on the total weight of the coolant composition.

[0031] The compositions may comprise antioxidants which may include hydrogen peroxide and amine or carboxylic acid salts such as triethanolamine, EDTA, amine borates, and amine carboxylates. Other optional additives that may be present in compositions may include; wetting agents and surfactants such as, for example, known ionic and non-ionic surfactants such as the po!y(oxyaSkySene) adducts of fatty alcohols; defoamers and/or lubricants such as the well-known poiysiioxanes and the poiyoxyalkylene glycols; wear inhibitors, such as the zinc diihJophosphates and the zinc thiocarbamates; lubricants, such as silicone pump lubricants; and other ingredients known in the art of coolants that do not adversely affect the coolant characteristics sought to be achieved by the end use of the coolant.

[0032] Other optional additives that may be present in commercial coolants include, but are not limited to: wetting agents and surfactants such as, for example, ionic and/or non-ionic surfactants such as the poly(oxyalkylene) adducts of fatty alcohols; defoamers and/or lubricants such as poiysiioxanes and poiyoxyalkylene glycols; wear inhibitors, such as zinc dithiophosphates and zinc thiocarbamates; lubricants, such as silicone pump lubricants; and other ingredients suitable for antifreeze/coolants that do not adversely affect the coolant characteristics sought to be achieved by the end use of the coolant.

[0033] The composition may include one or more nucleators which function to enhance the formation of particles of semi-crystalline polymers upon recrystallization of the semi- crystalline polymers. Generally, nucleating agents are high melting compounds which do not melt at processing temperature of the polymer and remain as discrete particles embedded in polymer melt. These insoluble particles behave as nucleators for the crystallization of polymer melts and generate innumerable crystallization sites resulting innumerous small spherulites some nucleating agents are soluble in polymer melt but they solidify before crystallization of polymer melt and, thus, generate sites for crystallization. Exemplary nucleating agents include benzylidene derivatives of sorbitols, metal salts of organic carboxylic and sulfonic acids and phosphate salts. Exemplary nucleating agents include metal salts of different mono, di and poly carboxylic aliphatic, substituted and un substituted aromatic acids, carboxylic acids containing cyclic and fused rings with alkali/alkaline earth metal belonging to IA, IIA and IMA group in periodic table have been used. U.S. Pat. Nos. 5,912,292, and 3,852,237 describe the use of sodium benzoate as nucleating agent, all incorporated herein by reference. U.S. Pat. Nos. 5,714,531 and 5,998,576 describe the use of rosin acid salts as nucleating agents , all incorporated herein by reference. Rosin is naturally occurring material containing mixtures of acids such as abietic acid, dehydroabietic acid and many other acids. Metallic salts of dehydorabietic acid are reported to be effective nucleating agents.

[0034] The pH of the composition may be adjusted for use as a coolant. The pH may be adjusted to be 7 or greater or 8 to 10. The pH may be adjusted by addition of a base which does not compromise the desired function of the compositions disclosed. [0035] Disclosed is a method for preparing a composition disclosed herein comprising: a) preparing the dispersion of particles of one or more semi-crystalline polymers in one or more polar liquids; and b) contacting the functionalized carbon nanoparticles with the one or more semi-crystalline polymers or with the dispersion of particles of one or more semi-crystalline polymers in one or more polar liquids. The functionalized carbon nanoparticles are dispersed in one or more polar liquids and the dispersion containing the functionalized carbon nanoparticles formed with the dispersion of particles of one or more semi-crystalline polymers in one or more polar liquids; the functionalized carbon nanoparticles are contacted with the one or more semi-crystalline polymers by adding them to the polar liquids while forming the particles of the one or more semi-crystalline polymers; contacting the functionalized carbon nanoparticles with the dispersion of particles of one or more semi-crystalline polymers; or any combination thereof. One or more of the polar liquids may be added after contacting the functionalized carbon nanoparticles with the one or more semi-crystalline polymers or with the dispersion of particles of one or more semi-crystalline polymers in one or more polar liquids. A dispersion of the functionalized carbon nanoparticles may be contacted with a dispersion of semi-crystalline polymers by blending the two together. The functionalized carbon nanoparticles may be contacted with the semi-crystalline polymer while forming the dispersion of the semi-crystalline polymer by adding the functionalized carbon nanoparticles to the dispersant prior to forming the particles of semi-crystalline polymers which allows the dispersion of the functionalized carbon nanoparticles in the semi-crystalline polymer particles. Alternatively the functionalized carbon nanoparticles can be added directly to the dispersion of particles to the semi-crystalline polymers wherein the nano-particles can be disposed in the dispersant, on the surface of the semi-crystalline polymers or both

[0036] Carbon nanoparticles may be functionalized by contacting carbon nanoparticles with a mixture of concentrated sulfuric and nitric acids to form OH^", COO^" or CO groups on the surface of the carbon nanoparticles. This process is described in US 2014/0312263, paragraphs 0033 and Example 1 , paragraphs 0058 to 0060, relevant portions incorporated herein by reference. Generally the process comprises contacting about a 3: 1 mixture of concentrated sulfuric acid and nitric acid with carbon nanoparticles with agitation to form a homogeneous mixture. The homogeneous mixture can be sonicated in a water bath multiple times (about 5) for about 30 minutes. The mixture can be agitated between each sonication. The particles can be washed with deionized water in multiple cycles after centrifuging, decanting and re-dispersing in deionized water until the pH of the suspension in water is above 3.0. The particles are separated from water by centrifuging and dried in an oven at about 60 °C. The functionalized carbon nanoparticles can be dispersed in a polar fluid after drying. The dispersion may be achieved by mixing to homogenize the mixture and multiple rounds of sonication, about 10 rounds work well. The mixture may be contacted with ammonium hydroxide to adjust the pH.

[0037] The functionalized carbon nanoparticles may be further functionalized by contacting them with aminoalcohols, such as alkanol amines. Alkanolamine refers to a hydrocarbon containing both a hydroxyl group and an amine group each attached to separate carbons. The alkanolamine may be a primary, secondary, or tertiary amine. The alkanolamine may be linear, branched, cyclic, aliphatic alkanolamine or aromatic alkanolamine. The functionalized carbon nanomaterial may be an alkanolamineized form of a carbon nanomaterial prepared using one or more alkanolamines. The alkanolamineized form of the carbon nanomaterial may be prepared by reacting a carbodiimide activated carbon nanomaterial with the alkanolamine. The alkanolamineized form of the carbon nanomaterial may be prepared by reacting with diisopropylcarbodimide (DIC), dimethylaminopropanol (DMAP), hydroxybenzotriazole (HOBt), and the alkanolamine in dimethylsulfoxide (DMSO), for example, by ultrasonication. The carbo-dimide may be dicyclohexylcarbodiimide (DCC), or ethyl-(N',N'-dimethylamino) propylcarbodi imide hydrochloride (EDC). The alkanolamine may contain no more than twenty carbon atoms. The alkanolamine may contain two or more carbon atoms. The alkanolamine may have a straight carbon chain. The alkanolamine may have a branched carbon chain. The alkanolamine may be selected such that it soluble in the polar fluid medium. The alkanolamine may be a polyetheramine, for example, those sold under the trade name Jeffamine monoamine (available from Huntsman Corp, molecular weight reported as up to 2000). The alkanolamine may be a piperazine derivative, for example, hydroxyethylpiperazine. The alkanolamine may be a cyclic alkanol amines, or an aromatic alkanol amine. Exemplary alkanolamines include, but are not limited to, monoethanolamine, diethanolamine, monoisopropanolamine, and amino-methyl-propanols, for example, 2-amino-2-methyl-1-propanol.

[0038] A mixture of functionalized carbon nanoparticles and one or more polar fluids may be prepared by ultrasonication as is known in the art. For example, ultrasonication uses >20 kHz ultrasonic waves to create cavitation in the fluid that results in mixing and deaggregation. The mixture may be prepared by high-shear mixing. The high-shear mixing uses a mixer which provides a high degree of shear to the fluid to disperse the nanoparticles in the fluid media. Ultrasonication is preferred for low-viscosity fluids while high-shear mixing is preferable for high-viscosity fluids. The dispersion may be prepared at room temperature and pressure.

[0039] Dispersion of the semi-crystalline polymers in a polar liquid can be performed by processes know in the art. Aqueous polyamide dispersions may be prepared according to any one of US 5,804,682; US 6,077,900; US 5,948,880; US 5,770,680; US 5,886, 135; US 5,723,538; or US 6,777,488 relevant parts incorporated herein by reference. Aqueous polyester dispersions may be prepared according to any one of US 6,020,420; US 7,893, 150; US 7,638,578; US 5,449,707, or US 6,777,488 US 2005/0027067 relevant parts incorporated herein by reference. Dispersions of polyolefins may be prepared according to Moncla, et al. US 7,803,865; Moncla et al. 7,947,776 or Van Sumeren et al. US 8,916,640; relevant parts incorporated herein by reference.

[0040] Polyolefin dispersions may be prepared in a water or mixture of polar liquids bath. The bath is maintained at a temperature at which the one or more polyolefins are in a molten or liquid state so as to facilitate dispersion of particles of the one or more polyolefins in water. The bath may be maintained at ambient temperatures, of about 18 °C or about 20 °C or greater. The bath may be maintained at a temperature of about 30 °C or less or about 25 °C or less. Other bath temperatures may be used. The particles of the one or more polyolefins in the bath are of a size as described herein. The dispersions may optionally include a filler wetting agent. A filler wetting agent generally may help make the filler and the polyolefin dispersion more compatible. Useful wetting agents include phosphate salts, such as sodium hexametaphosphate. A filler wetting agent can be included in a composition of the present invention at a concentration of at least about 0.5 part per 100 parts of filler, by weight. The dispersion may optionally include a thickener. Thickeners may be useful to increase the viscosity of low viscosity dispersions. Thickeners suitable for use may be any known in the art such as for instance polyacrylate type or associate non-ionic thickeners such as modified cellulose ethers. For example, suitable thickeners include ALCOGUM™ VEP-II (trade name of Alco Chemical Corporation), RHEOVIS™ and VISCALEX™ (trade names of Ciba Ceigy), UCAR ® Thickener 146, or ETHOCELL™ or METHOCELL™ (trade names of the Dow Chemical Company) and PARAGUM™ 241 (trade name of Para-Chem Southern, Inc.), or BERMACOL™ (trademark of Akzo Nobel) or AQUALON™ (trademark of Hercules) or ACUSOL ® (trademark of Rohm and Haas). Thickeners may be used in any amount necessary to prepare a dispersion of desired viscosity. The ultimate viscosity of the dispersion is, therefore, controllable. Addition of the thickener to the dispersion including the amount of filler may be performed with conventional means to result in viscosities as needed. Also, embodiments of the present disclosure may be characterized by their stability when a filler is added to the polyolefin / dispersion stabilizing agent mixture. In this context, stability refers to the stability of viscosity of the resultant aqueous polyolefin dispersion. In order to test the stability, the viscosity is measured over a period of time. Preferably, viscosity measured at 20 °C should remain +/- 10% of the original viscosity over a period of 24 hours, when stored at ambient temperature. The bath can be prepared by contacting the ingredients with agitation or milling in a heated vessel, for instance in a batch process. The one or more polyolefins and a dispersion stabilizing agent may be melt-kneaded in an extruder along with water and a neutralizing agent to form a dispersion. A filler may be added during or after blending the one or more polyolefins and dispersion stabilizing agent. After formation of the dispersion additional polar liquids may be added to achieve the desired polar liquid concentration as disclosed herein.

[0041] Disclosed is a method comprising; a) contacting a composition disclosed herein with a system that generates heat; b) transporting the composition from the system that generates the heat; and c) contacting the composition with a system that cools the composition. The composition may be continuously moved to contact the system that generates heat and the cooling system in sequence during operation. The composition may be contained in a closed system that continuously moves it through the heat generating system and the cooling system. The composition may be exposed to temperatures of about 120 °C or greater when in contact with the system that generates heat, about 130 °C or greater or about 140 °C or greater when in contact with the heat generating system. The composition may be exposed to temperatures of about 180 °C or less when in contact with the system that generates heat, about 160 °C or less or about 150 °C or less when in contact with the heat generating system. The composition may be cooled to about 30 °C or greater when in contact with the cooling system, about 60 °C or greater or about 100 °C or greater when in contact with the cooling system. The composition may be cooled to about 110 °C or less when in contact with the cooling system, about 80 °C or less or about 60 °C or less when in contact with the cooling system. The heat generating system may be be any system that generates heat which requires cooling. The systems may be part of transportation systems, for examples automobiles and trucks, buses, motorcycles, recreational vehicles and the like. The cooling system can be any cooling system that cools fluid compositions contacted with heat generating systems, for example radiators, cooling tubes, cooling towers, and all other types of cooling heat exchangers, and the like. Exemplary systems include engines, transmission hydraulic fluids, engine oil systems, battery systems, or non-mobile systems such as computer central processing units (CPUs) and the like. During operation of the method the particles of one or more semi-crystalline polymers at least partially melt in contact with the system that generates the heat (absorbing that heat energy as it melts) and the one or more semi- crystalline polymers recrystallize when in contact with the cooling system (giving back the heat energy as it crystallizes).

Illustrative Embodiments of the Invention

[0042] The following examples are provided to illustrate the invention, but are not intended to limit the scope thereof. All parts and percentages are by weight unless otherwise indicated. [0043] Example 1

Chemjcai for u\a:

¾/a"e/e_iS D/C HOBt DMAP G CONHCH₂CH₂OH

[0044] To a 100 mL round-bottom flask add 15 ml_ DMSO. Dissolve 252.4 mg DIC, 130 mg HOBt, and 70 mg DMAP into the DMSO. Stir the mixture for 15 minutes at room temperature. Add 450 mg graphene nanoplatelets to the flask (where G represents the carbon structure of the graphene nanoplatelet) and stir for 10 minutes. Treat the flask contents with ultrasonication for 1 hour using a Branson ultraprobe sonicator at 10% of the maximum available amplitude for 20 minutes at room temperature and pressure. Add 450 mg monoethanolamine (MEA) to the flask. Treat the flask contents with ultrasonication for 6 hours. Centrifuge the contents of the flask at 7800 rpm at 25 to 30 °C for 20 minutes. Remove the supernatant solution of graphene dispersion from the flask and separate the solvent using vacuum filtration with a PTFE membrane (0.45 μηι cut off). Wash the black solid on the filter three times with dichloromethane (DCM) and three times with MeOH and dry in a vacuum oven at 60 °C for one day. X-Ray photoelectron spectroscopy indicates that the graphene is functionalized as an amide of MEA and a carboxylic acid salt of MEA. The dispersion instability, as measured using a LUMiSizer^® (manufactured by LUM GmbH) at 4000 rpm for 24 hours at 20 ^°C is 0.11.

[0045] Example 2 - Coolant formulations

[0046] Three commercial automotive coolant formulations are used a base for the following experiments. All have a ratio of 50 percent water and 50 percent ethylene glycol.

[0047] Formulation 1 has a pH of about 7.0 and formulations 2 and 3 have a pH of about 9.0. A polyolefin dispersion in water (A) having a total of 46 percent by weight of solids in water comprising high density polyethylene 58 percent, maleic anhydride modified polyethylene 13 percent, a copolymer of methacrylic acid and ethylene 22 percent and a maleic anhydride grafted polyethylene wax, 7 percent. This dispersion when completely dried of all water has a melting endotherm starting at -100 C and completing at -135 C and will recrystallize on cooling starting at -125 C and completing at -85 C. The total heat of fusion in both melting and recrystallization of this "neat" semi-crystalline polymer is about 86-88 J/g (86,000 - 88,000 J/Kg) (see Figure 1 showing the DSC of the semi-crystalline polymer mixture used for the example which is dried to remove all water before testing). [0048] (A) is added to the coolant compositions to prepare dispersions (B) containing 6 wt percent of polymer particles. The pH of the mixtures (B) is 9.0, 10.0 and 10.0. After 24 hours the mixtures show no settling. A dispersion of 5 percent by weight graphene in a 50/50 mixture of ethylene glycol (C) and each of the coolant mixtures (B) are contacted at 50/50 volume percent. The heat capacities of the mixtures vary from about 3.1 J/gK at 25 C to about 3.6 J/gK at 140 C. The three samples show a distinct melting endotherm starting at about 124 C and completing at about 135 C. A melting endotherm of about 2 ~J/g (2000 J/Kg) of fluid at 3 percent polymer solids loading (dispersion solids). This corresponds to about 2000 J/Kg + 3500 J/KgK or 5500 J/Kg of total energy absorbance energy available across the endotherm cycle (latent heat of the semi-crystalline polymer fraction of this coolant formulation in addition to the heat capacity of the ethylene glycol/water antifreeze mixture. During cooling the same amount of energy is released. Table 1 shows the composition of the coolant formulations tested.

[0049] Figure 2 shows the DSC of the mixture with the heat capacity in J/gK and the melting endotherm (near 128 °C) of the polymeric additive.

[0050] Table 1

[0051] Parts by weight as used herein refers to 100 parts by weight of the composition specifically referred to. Any numerical values recited in the above application include all values from the lower value to the upper value in increments of one unit provided that there is a separation of at least 2 units between any lower value and any higher value. As an example, if it is stated that the amount of a component or a value of a process variable such as, for example, temperature, pressure, time and the like is, for example, from 1 to 90, preferably from 20 to 80, more preferably from 30 to 70, it is intended that values such as 15 to 85, 22 to 68, 43 to 51 , 30 to 32 etc. are expressly enumerated in this specification. For values which are less than one, one unit is considered to be 0.0001 , 0.001 , 0.01 or 0.1 as appropriate. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value, and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner. Unless otherwise stated, all ranges include both endpoints and all numbers between the endpoints. The use of "about" or "approximately" in connection with a range applies to both ends of the range. Thus, "about 20 to 30" is intended to cover "about 20 to about 30", inclusive of at least the specified endpoints. The term "consisting essentially of" to describe a combination shall include the elements, ingredients, components or steps identified, and such other elements ingredients, components or steps that do not materially affect the basic and novel characteristics of the combination. The use of the terms "comprising" or "including" to describe combinations of elements, ingredients, components or steps herein also contemplates embodiments that consist essentially of the elements, ingredients, components or steps. Plural elements, ingredients, components or steps can be provided by a single integrated element, ingredient, component or step. Alternatively, a single integrated element, ingredient, component or step might be divided into separate plural elements, ingredients, components or steps. The disclosure of "a" or "one" to describe an element, ingredient, component or step is not intended to foreclose additional elements, ingredients, components or steps.

Claims

CLAIMS What is claimed is:

Claim 1. A composition comprising:

a) one or more polar liquids;

b) one or more chemically functionalized carbon nanoparticles; and

c) particles of one or more semi-crystalline polymers having a melting point and

recrystallization point between about 80 °C and about 180 °C and a latent heat of greater than about 20,000 J/Kg dispersed in the one or more polar liquids;

wherein the composition exhibits thermal conductivity of about 0.15 W/mK or greater and a total heat capacity of about 3400 J/Kg*K or greater, and a melting endotherm of about 1000 J/Kg or greater.

Claim 2. A composition according to Claim 1 wherein the one or more semi-crystalline polymers or copolymers having a melting point from about 80 to about 180 °C comprise one or more polyolefins, one or more polyesters, one or more polyamides, one or more polystyrenes, or copolymers of any of these polymer types or mixtures thereof.

Claim 3. A composition according to Claim 1 or 2 wherein the carbon nanoparticles are functionalized to have one or more carbonyl, carbonyloxy, hydroxyl, amines ureas, amides or aminoalcohol groups on their surface.

Claim 4. A composition according to any one of the preceding claims wherein the carbon nanoparticles have a particle size of about 1 nm to about 100 nm measured in the smallest direction.

Claim 5. A composition according to any one of the preceding claims wherein the carbon nanoparticles are graphene like platelets that have about 5 to about 20 nm in thickness and about 5 to about 50 microns in diameter

Claim 6. A composition according to any one of the preceding claims wherein the particle size of the semi-crystalline polymers is about 0.2 microns to about 10 microns.

Claim 7. A composition according to any one of the preceding claims wherein the composition includes one or more dispersants capable of stabilizing the one or more carbon nanomaterial or the one or more semi-crystalline polymers in the one or more polar liquids.

Claim 8. A composition according to any one of the preceding claims wherein the particles of one or more semi-crystalline polymers comprise one or more polyolefins and contain a polyolefin having grafted to the backbone maleic anhydride or a hydrolysis product thereof.

Claim 9. A composition according to any one of the preceding claims which includes one or more of a nucleating agent capable of aiding the crystallization of the one or more semi- crystalline polymers, one or more corrosion inhibitors or one or more anti-foaming agents.

Claim 10. A composition according to any one of the preceding claims wherein:

a) the one or more polar liquids are present in an amount of about 30 to 75 percent by weight;

b) the one or more functionalized carbon nanoparticles are present in an amount of about 0.001 to about 10 percent by weight; and

c) the particles of one or more semi-crystalline polymers dispersed in the one or more polar liquids are present in an amount of about 0.5 to about 50 percent by weight; wherein the percent by weights are based on the weight of the composition.

Claim 1 1. A composition according to any one of the preceding claims wherein the carbon nanoparticles are dispersed in the polar liquid, dispersed in the particles of one or more semi-crystalline polymers, located on the surface of the particles of one or more semi- crystalline polymers or any combination thereof.

Claim 12. A composition according to any one of the preceding claims wherein. the polar liquid comprises one or more of water, a glycol, a polyglycol, an alkyl alcohol, a solution of a salt in water, or a mixture thereof.

Claim 13. A method comprising

a) contacting a composition according to any one of Claims 1 to 12 with a system that generates heat;

b) transporting the composition from the system that generates the heat; and

c) contacting the composition with a system that cools the composition.

Claim 14. A method according to Claim 13 wherein the composition is continuously moved to contact the system that generates heat and the cooling system in sequence during operation.

Claim 15. A method according to Claim 13 or 14 wherein the system that generates heat is an engine and the cooling system is a radiator.

Claim 16. A method according to any one of Claims 13 to 15 wherein the system that generates heat reaches temperatures of from about 120 °C to about 180 °C and the cooling system cools the composition to about 60 °C to about 120 °C.

Claim 17. A method according to any one of Claims 13 to 16 wherein the particles of one or more polyolefins at least partially melt in contact with the system that generates the heat and the one or more polyolefins crystallize when in contact with the cooling system.

Claim 18. A method for preparing a composition according to any one of Claims 1 to 12 comprising:

a) preparing the dispersion of particles of one or more semi-crystalline polymers in one or more polar liquids; and

b) contacting the functionalized carbon nanoparticles with the one or more semi-crystalline polymers or with the dispersion of particles of one or more semi-crystalline polymers in one or more polar liquids.

Claim 19. A method according to Claim 18 wherein the functionalized carbon nanoparticles are dispersed in one or more polar liquids and contacting the dispersion containing the functionalized carbon nanoparticles formed with the dispersion of particles of one or more semi-crystalline polymers in one or more polar liquids; the functionalized carbon

nanoparticles are contacted with the one or more semi-crystalline polymers by adding them to the polar liquids while forming the particles of the one or more semi-crystalline polymers; contacting the functionalized carbon nanoparticles with the dispersion of particles of one or more semi-crystalline polymers; or any combination thereof.

Claim 20. A method according to Claims 18 or 19 wherein one or more of the polar liquids are added after contacting the functionalized carbon nanoparticles with the one or more semi-crystalline polymers or with the dispersion of particles of one or more semi-crystalline polymers in one or more polar liquids.