WO2017173176A1

WO2017173176A1 - Microencapsulated composite phase change materials

Info

Publication number: WO2017173176A1
Application number: PCT/US2017/025193
Authority: WO
Inventors: Steven Keith Mcneil; William Rusty Sutterlin
Original assignee: Entropy Solutions Llc
Priority date: 2016-04-01
Filing date: 2017-03-30
Publication date: 2017-10-05

Abstract

This invention generally relates to thermoregulation, thermal protection and insulation, Phase Change Material (PCMs) and nucleating agents. In particular, in alternative embodiments, provided are Thermal Energy Storage (TES) systems comprising Phase Change Material (PCMs) compositions for thermal management in different applications such as building, automotive, and industrial applications. Provided are PCM-comprising compositions comprising a porous, or a macro-, micro- or nano-porous or equivalent adsorbent and a PCM, wherein the PCM is absorbed into the porous, or a macro-, micro- or nano-porous or equivalent structure of the PCM and in alternative embodiments, the resulting composite PCM particles are encapsulated, e.g., microencapsulated, using a physical coating process.

Description

MICROENCAPSULATED COMPOSITE PHASE CHANGE

MATERIALS

RELATED APPLICATIONS

This Patent Convention Treaty (PCT) International Application claims the benefit of priority to U.S. Provisional Application No. 62/316,661 , filed April 1 , 2016. The aforementioned application is expressly incorporated herein by reference in its entirety and for all purposes.

FIELD OF THE INVENTION

This invention generally relates to thermoregulation, thermal protection, and insulation, Phase Change Material (PCMs) and adsorbant materials. In particular, in alternative embodiments, provided are Thermal Energy Storage (TES) systems comprising Phase Change Material (PCMs) compositions for thermal management in different applications such as building, automotive, and industrial applications. Also provided are PCM-comprising compositions, including TES systems, comprising a porous structure, or macro-, micro- or nano-structured or equivalent, structure adsorbent and a PCM, wherein the PCM is absorbed into the porous structure of the PCM and in alternative embodiments, the resulting composite PCM particles are encapsulated using a physical coating process.

BACKGROUND OF THE INVENTION

There is a general desire in all industries to be energy efficient. There is also a general desire to reduce the use of fossil fuel resources due to concerns over climate change and energy security. Buildings, for example, require significant amounts of energy for heating and cooling and there is a need to reduce the costs associated with thermal management. Energy capture and storage from building and the controlled release of stored energy back into the building is increasingly viewed as a critical component to reducing overall energy demand in commercial and industrial applications. The thermal management of temperature sensitive payloads during transport can also require significant amounts of energy. In the automotive industry, there is a desire to increase efficiency and reduce the fuel usage associated with maintaining a comfortable temperature in the cabin of vehicles.

One approach of decreasing the amount of energy needed for thermal management is the use of phase change materials. A "phase change material" (PCM) is a material that stores or releases a large amount of energy during a change in state, or "phase", e.g. crystallization (solidifying) or melting (liquefying) at a specific temperature. The amount of energy stored or released by a material during crystallization or melting, respectively, is the latent heat of that material. During such phase changes, the temperature of the material remains relatively constant. This is in contrast to the "sensible" heat, which does result in a temperature change of the material, but not a phase change. The phase change process of PCMs requires sensible heat and latent heat. Sensible heating is the thermal energy stored to initiate the melting process. Latent heating is the thermal energy stored during the phase change process (solid state to the liquid state). It is known that the main advantages of latent heating are the large storing density and isothermal absorption/release of thermal energy.

PCMs are therefore "latent" thermal storage materials. A transfer of energy occurs when the material undergoes a phase change, e.g. from a liquid to a solid and thus helps to maintain the temperature of a system. When heat is supplied to the system in which the temperature is at the melting point of the PCM, energy will be stored by the PCM, resulting in a mediating effect on the temperature of the system. Similarly, when the temperature of the system decreases to the crystallization temperature of the PCM, the energy stored by the PCM will be released into the surrounding environment. The amount of energy stored or released by a material is a constant, and is that material's latent heat value. For example, water has a latent heat of 333 J/g; a gram of water will release 333 J of energy to its surrounding environment during crystallization (freezing), at 0 °C without changing temperature. Similarly, a gram of frozen water will absorb 333 J of energy from its surrounding environment during melting without an increase in temperature from 0 °C.

There are two primary characteristics that must be considered for a specific application of a PCM: 1 ) the melting/crystallization temperature of the material, and 2) the latent heat value. A high latent heat value is the most desirable characteristic of a phase change material. A high latent heat value means that the material will be able to store or release large amounts of energy during a phase change, thus reducing the quantity of supplied energy needed to heat or cool a system. A latent heat value of 160 J/g or higher is considered acceptable for a PCM material in thermal storage applications. The melting/crystallization temperature is important because every thermal storage system has a unique optimal temperature range. These two factors together inform the potential applications for a specific PCM. For example, although water has a very high latent value (333 J/g), it would not be suitable for use as a PCM in building materials, as buildings are typically maintained at temperatures around 70°F, well above the melting/crystallization temperature of water.

The majority of commercially available PCMs are salt hydrates or paraffins. Both salt hydrates and paraffins have inherent disadvantages in commercial applications. Salt hydrates, while cheap to produce, have inconsistent melting points, and have a tendency to supercool (a process in which the temperature of a material is lowered to below its melting point without the material undergoing crystallization). Salt hydrates are also known to undergo significant thermal expansion and can be highly toxic and corrosive. Paraffins make suitable PCMs in that they have favorable latent heat values and consistent melting points. However, the high latent heats of paraffin-based PCMs (in excess of 230 J/g) require compositions comprising high purities of paraffins, necessitating the use of expensive processing technology. Further, paraffins are limited in their potential range of phase change temperatures, leading to the use of mixed PCM compositions with reduced latent heat values.

In certain applications, it is desirable for a PCM to be encapsulated, i.e. encased or enclosed in a material that provides a physical barrier between the PCM and its surrounding environment. Additional benefits of encapsulation may include: the prevention of leakage of the PCM into its surrounding environment, enhancement of thermal and mechanical stability, and an increase in heat transfer rate. Encapsulation therefore enables the use of PCMs in certain applications wherein they may not otherwise be utilized, e.g. as building materials. However, many PCMs are incompatible with common coating materials (e.g. plastics and metals) due to their tendency to corrode or for other incompatibility reasons.

Methods for encapsulation of a PCM have been described in the art and general comprise the use of expensive monomers and surfactants as well as exotic catalysts which may not be fully recovered or recycled. Other encapsulation methods in the art include labor and time-intensive manual encapsulation techniques that are not suitable for mass production. In general, available PCM encapsulation methods are prohibitively expensive, restricting their adoption in low economic-margin, mass market applications such as building materials.

It is therefore desirable to develop methods for the encapsulation of PCMs that are low-cost and that can be efficiently scaled to achieve large production volumes. SUMMARY OF THE INVENTION

In alternative embodiments, provided are Phase Change Material (PCM)-comprising compositions comprising a composite PCM, wherein the composite PCM is comprised of an adsorbent material having a plurality of pores or macro-, micro- or nano-structures or equivalents, and a Phase Change Material (PCM), wherein the PCM is absorbed into or onto the pores, macro-, micro- or nano-structures or equivalent structures, of the adsorbent material.

In alternative embodiments, the Phase Change Material (PCM) is encapsulated, e.g., microencapsulated, or coated, and optionally the encapsulated or coated composite PCM particles have a diameter, or an average diameter, in the range of between about 1 microns to 5 millimeters (1 pm to 5 mm), or between about 10 microns to 3 millimeters (10 m to 3 mm), or between about 5 m to 10 mm, or or between about 0.5 pm to 15 mm.

In alternative embodiments, the composite PCM is encapsulated or coated by one or more layers of a polymer material, e.g., wherein the adsorbent material can be a plastic, and optionally the plastic is selected from the group consisting of: high-density polyethylene (HDPE) or polyethylene high-density (PEHD), Low-density polyethylene (LDPE), Poly(methyl methacrylate) (PMMA) or acrylic glass or acrylic (e.g., PLEXIGLAS™, ACRYLITE™, LUCITE™, PERSPEX™), polystyrene, Ethylene-vinyl acetate (EVA) or poly(ethylene-vinyl acetate) (PEVA), poly(ethylene terephthalate) (PET), thermoplastic elastomers (TPEs) such as styrenic block copolymers (TPE-s), ethylene/butylene block copolymers, crystalline ethylene/butylene block copolymers, thermoplastic olefins (TPE-o), elastomeric alloys (TPE-v or TPV), thermoplastic polyurethanes (TPU), thermoplastic copolyester, thermoplastic polyamides, acrylonitrile butadiene styrene (ABS), polypropylene (PP) or polypropene, equivalents thereof and combinations thereof.

In alternative embodiments, the adsorbent material is selected from the group consisting of: activated carbon, graphite, expanded graphite, fullers earth, perlite, diatomaceous earth, cellulose, fibers, silica, celite, wood pulp, corn stover, biomass, bentonite, vermiculite, gypsum, silicon dioxide, attapulgite, graphene oxide, aluminum oxide, cement, molecular sieves, zeolites, metal foams, kaolinite, chlorite, montomorillonite, muscovite, illite, cookeite, GRIT-O-COBB™, silicates, fumed silica, cenospheres, polyacrylate, sepiolite, expanded clay aggregates, mica clays, smectite clays, and equivalents thereof, and a combination thereof.

In alternative embodiments, the PCM is an organic or an inorganic material, wherein optionally the PCM is selected from the group consisting of: fatty acids, fatty acid derivatives, salt hydrates, fatty alcohols, glycols, paraffins, sugars, sugar alcohols, eutectics and combinations thereof.

In alternative embodiments, provided herein are methods for thermoregulating, thermal protecting or insulating a product of manufacture, a building, a storage compartment or facility; an insulation or construction material; electronics and computers, automotive materials; airplanes; boats; industrial machinery; weapons systems, packaging materials or containers; pharmaceuticals or drug storage or delivery devices; cloth, fabrics or garments; footwear, energy storage or temperature stabilization systems, comprising use of or incorporation of a Phase Change Material (PCM)-comprising composition as provided herein.

In alternative embodiments, provided are: products of manufacture, a building, a storage compartment or facility; an insulation or construction material; electronics and computers, automotive materials; airplanes; boats; industrial machinery; weapons systems, packaging materials or containers; pharmaceuticals or drug storage or delivery devices; cloth, fabrics or garments; footwear, energy storage or temperature stabilization systems, comprising use of or incorporation of a Phase Change Material (PCM)-comprising composition as provided herein. The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

All publications, patents, patent applications cited herein are hereby expressly incorporated by reference for all purposes.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 schematically illustrates an exemplary coating process comprising:

composite adsorbent PCM particles (6) are fluidized by air passing through the perforated disc (3) causing the particles to travel upward through the partition (4) into the expansion chamber (7). The particles descend back down into the down-bed region (8), and the fluidization cycle is repeated. The polymer coating solution is transferred through tubing (1 ) by a peristaltic pump to the spray nozzle (2). An additional inlet metal tube located in (1 ) allows pressurized air to atomize the polymer coating solution into small particles through the spray nozzle (2). As the composite adsorbent PCM particles travel upwards through the partition (4), they enter the coating zone (5) where they come into contact with the atomized polymer coating solution depositing on the particles' surfaces. The solvent rapidly evaporates from the coating solution leaving behind a dry polymer coating. In alternative embodiments, this process is repeated many times allowing uniform film formation on the particles' surfaces.

FIG. 2 illustrates a Scanning Electron Microscopy (SEM) image which was performed on the samples of exemplary compositions as provided herein to measure the shell thickness (the width of the shell) of various particle sizes, as discussed in detail in Example 1 , below.

FIG. 3 illustrates a Scanning Electron Microscopy (SEM) image which was performed on the samples of exemplary compositions as provided herein to measure the shell thickness of various particle sizes, as discussed in detail in Example 2, below.

Reference will now be made in detail to various exemplary embodiments of the invention. The following detailed description is provided to give the reader a better understanding of certain details of aspects and embodiments of the invention, and should not be interpreted as a limitation on the scope of the invention.

DETAILED DESCRIPTION OF THE INVENTION

In alternative embodiments, provided are organic phase change material-comprising compositions comprising an organic or an inorganic phase change material (PCM), wherein the PCM is absorbed in or onto an adsorbent material, and in alternative embodiments, the resulting composition (i.e., the PMC-adsorbent composition, herein referred to as the "composite PCM") is encapsulated. The encapsulation can be by use of methods that are inexpensive and scalable.

In alternative embodiments, composite PCMs are microencapsulated; i.e., encapsulated in a process that results in the generation of encapsulated composite PCM particles. In alternative embodiments, encapsulated or coated composite PCM particles have a diameter in the range of between about 10 microns to 3 millimeters (10 pm to 3 mm), or between about 5 pm to 5 mm, or between about 0.5 pm to 15 mm. In alternative embodiments, encapsulation is done by a process that addresses limitations of other microencapsulation methods in the art, for example, the need for expensive monomers, surfactants, catalyst, and complex encapsulation techniques.

In alternative embodiments, the equipment used in the encapsulation or coating process have low operating cost, high production efficiencies, and are easily scaled. In alternative embodiments, the process allows for the encapsulation or coating of composite PCMs of varying particle sizes and can utilize numerous polymer materials as the encapsulating material. In alternative embodiments, the process can be used to encapsulate composite PCMs wherein the PCM has a high phase change temperature, e.g. , greater than 60°C. In alternative embodiments, the final product, i.e., the encapsulated composite PCM is a dry product or a substantially dry product, and does not require an additional drying step, thereby lowering manufacturing costs.

In alternative embodiments, provided are thermal energy storage (TES) systems comprising a Phase Change Material (PCM) comprising, or absorbed onto, an adsorbent material, wherein the PCM is absorbed by the adsorbent, for example, absorbed onto or into pores or equivalent structures (e.g., nanogrooves or nanopits) of the adsorbant material, and wherein the PCM is capable is of undergoing a solid-to-liquid and liquid to-solid phase change. In alternative embodiments, during the solid-to-liquid phase change, the PCM absorbs or "stores" latent heat from its surrounding environment. In alternative embodiments, during the liquid-to-solid phase change, the PCM releases its "stored" energy into its surrounding environment.

Composite PCMs

In alternative embodiments, provided are compositions and products of manufacture comprising Phase Change Materials (PCMs), wherein the PCMs can comprise any PCM, including for example organic materials, including a biomass or plant derived materials, or inorganic compositions. In alternative embodiments, PCMs can be compositions as described in e.g., WO/2016/025536 A1 , WO2015/164654 A1 and US 2013-0134347 A1 .

In alternative embodiments, compositions and products of manufacture provided herein comprise a PCM and an adsorbent, e.g., a porous or a macro- , a micro- or a nano-structured (e.g., pored, grooved, pitted, nano-grooved or nano-pitted or equivalent) adsorbent, wherein the adsorbent absorbs the PCM.

In alternative embodiments, the resulting composite PCM (the structure comprising the adsorbent and the PCM, wherein the PCM has been absorbed into or into the adsorbent, including into or onto pores or macro-, micro- or nano- structures of the adsorbent) is encapsulated using a polymer. In alternative embodiments, the adsorbent has a large specific surface area, is capable of absorbing large amounts of a fluid and comprises a porous or macro-, micro- or nano-structured or equivalent structure. In alternative embodiments, the structure of the adsorbent can comprise a nano-, micro-, or macro-porous or equivalent structure. Suitable adsorbent materials include, without limitation, activated carbon, graphite, expanded graphite, fullers earth, perlite, diatomaceous earth, cellulose, fibers, silica, celite, wood pulp, corn stover, biomass, bentonite, vermiculite, gypsum, silicon dioxide, attapulgite, graphene oxide, aluminum oxide, cement, molecular sieves, zeolites, metal foams, kaolinite, chlorite, montomorillonite, muscovite, illite, cookeite, GRIT-O- COBB™ (!-Wood-Care, Sherburne, NY), silicates, fumed silica, cenospheres, expanded clay aggregates, mica clays, smectite clays, and polyacrylate, and combinations thereof.

In alternative embodiments, various purification or other processing steps may be performed on the adsorbent material, e.g. drying or other process(es) that increase the functionality of the adsorbent and/or increase the absorption capacity of the adsorbent.

In alternative embodiments, any PCM that is compatible with a given adsorbent material may be used in the composite PCMs. Suitable PCMs include, without limitation, fatty acids and derivatives thereof, salt hydrates, fatty alcohols, glycols, paraffins, sugars and sugar alcohols, and eutectics.

In alternative embodiments, the PCM is absorbed in to a plastic material. In alternative embodiments, composite PCMs as provided herein can be processed to form pellets or spheres using, for example, methods EP21 19498A1 , US20121 0049402A1 , or US2013/0134347A1 . Suitable plastics include, without limitation, high-density polyethylene (HDPE) or polyethylene high-density (PEHD), Low-density polyethylene (LDPE), Poly(methyl methacrylate) (PMMA) or acrylic glass or acrylic (e.g. , PLEXIGLAS™, ACRYLITE™, LUCITE™, PERSPEX™), polystyrene, Ethylene-vinyl acetate (EVA) or poly(ethylene-vinyl acetate) (PEVA), poly(ethylene terephthalate) (PET), thermoplastic elastomers (TPEs) such as styrenic block copolymers (TPE-s), ethylene/butylene block copolymers, crystalline ethylene/butylene block copolymers, thermoplastic olefins (TPE-o), elastomeric alloys (TPE-v or TPV), thermoplastic polyurethanes (TPU), thermoplastic copolyester, thermoplastic polyamides, acrylonitrile butadiene styrene (ABS), and polypropylene (PP) or polypropene, and equivalents.

In alternative embodiments, the adsorbent material possesses desirable properties including the ability to serve as a rigid support material for the PCM that has been absorbed into the pore or equivalent structure of the adsorbent. Other desirable adsorbent characteristics include a pore or equivalent structure that prevents leakage of the PCM and does not negatively impact the thermal storage or phase change properties of the PCM.

In alternative embodiments, the PCM is absorbed into the pore or equivalent structure of the adsorbent at atmospheric pressure conditions. In alternative embodiments, the process is conducted under vacuum. In the atmospheric pressure process, the PCM is heated in any suitable vessel to above the phase change temperature to generate a homogeneous liquid. After the phase change material has completely melted, the adsorbent material is added to the vessel and stirred at a temperature above the phase change temperature of the PCM (i.e. while the PCM is in a liquid state). After a sufficient mixing time, the temperature is lowered to a temperature below the phase change temperature of the PCM, allowing the phase change material to solidify to produce free-flowing composite PCM particles which can be dry or substantially dry.

In alternative embodiments, the process for incorporating the PCM into the pore or equivalent structure of the adsorbent is conducted under a vacuum. In the vacuum process, the PCM and adsorbent material are transferred to any suitable container or vessel, the container or vessel having been connected to a vacuum pump. The container or vessel, wherein the PCM and the adsorbent material have been added, is sealed and maintained at temperature below that of the phase change temperature of the PCM. The container or vessel is vacuumed, i.e., the air and water inside the container or vessel are removed from the container or vessel using a vacuum pump, for a period of time that is sufficient to allow for most or substantially all of the air and any water to be removed from the container or vessel. The pressure of the vacuum will vary depending on several variables including the ambient temperature, and various physical properties of the PCM and the adsorbent material. Following the removal of most or substantially all of the air and any water from the container or vessel, the temperature of the container or vessel is increased to a temperature that is above the phase change temperature of the PCM, thereby causing the PCM to melt. Once in a liquid state, the PCM is absorbed into the porous structure, or macro-, micro- or nano-structured or equivalent, of the adsorbent generating a composite PCM material. The vacuum is then released, allowing for the pressure of the container or vessel to increase to ambient pressure, aiding in the flow of the PCM into the pore or equivalent structures of the adsorbent material. In alternative embodiments, the mixture can be stirred or otherwise agitated to encourage the absorption of any residual PCM into or onto (adsorbed onto) the adsorbent material. In alternative embodiments, once it has been determined that the PCM has been sufficiently absorbed into the porous structure, or macro-, micro- or nano-structured or equivalent structure, of the absorbent, the temperature of the container or vessel is decreased to a temperature below the phase change temperature of the PCM, allowing the PCM to solidify and generating composite PCM particles wherein the porous structure, or macro-, micro- or nano-structured or equivalent, structures of the adsorbent is filled (partially or completely) with the PCM.

In alternative embodiments, following the generation of the composite PCM particles, the particles can be separated by particle size based on a specific application of the product. For example, certain PCM-containing materials or systems may require a highly uniform particle size while others may accept a range of particle sized. Similarly, certain applications may require a small composite PCM particle size while others may be optimized for a larger particle size. The composite PCM particles can be separated into groups based on particle size using any method known in the art, e.g. by using a shaker sieve. In alternative embodiments, the separation process can be performed before or after the adsorption process (i.e. the adsorbent particles can be separated by size prior to mixing with the PCM).

Composite PCM encapsulation

In alternative embodiments, provided are methods for encapsulating (or coating), including microencapsulating, the generated composite PCM particles, i.e. particles of the adsorbent material, wherein a PCM has been absorbed into the adsorbent porous structure, or macro-, micro- or nano- structured or equivalent, structures of the adsorbent material and wherein the absorbed PCM is capable of undergoing solid-to-liquid and liquid-to-solid phase changes. In alternative embodiments, the generated composite PCM particles are encapsulated, covered in a coating, e.g., a shell, or embedded in a matrix, thereby generating encapsulated (or covered, shelled or the like) composite PCM particles that can be used in a range of applications, e.g., industrial or other applications, e.g., storage facility, home, boat or vehicle insulation.

In alternative embodiments, the encapsulation process creates an impermeable physical layer of material between the resulting capsules (comprised of the composite PCM particles comprising an adsorbent and a PCM wherein the PCM has been adsorbed into or onto porous structure, or macro-, micro- or nano-structured or equivalent, structure of the PCM and an encapsulating layer, e.g. a shell or polymer matrix) and the surrounding environment in which they are placed. In alternative embodiments, the shell or outer layer of the capsules or equivalents prevent the leakage of any of the components of the composite PCM particles from leaking or otherwise coming into contact with their surrounding environment, thereby enabling potentially hazardous or corrosive materials to be utilized as components of the composite PCM particles, or at the least preserving the integrity of the composite particles, thereby increasing their efficiency and longevity. In alternative embodiments, the encapsulation of the composite PCM particles also enhances thermal and mechanical stability of the composite PCMS, and increases the rate of heat transfer between the PCM and its surrounding environment.

In alternative embodiments, the process used for encapsulating the composite PCM particles is a physical (as opposed to chemical) encapsulation process that does not rely on the use of expensive monomers (which polymerize), surfactants, or catalysts. In alternative embodiments, the equipment used in the encapsulation process have low operating costs achieve economies of scale. In alternative embodiments, the encapsulation process allows for the encapsulation of a range of composite PCM particle sizes and is capable of utilizing a range of polymer as a coating material. In alternative embodiments, the encapsulation process allows for the encapsulation of composite PCM particles comprising a PCM with a high temperature of phase change, e.g., greater than about 60°C. In alternative embodiments, the encapsulated composite PCM particles generated in the encapsulation process do not require a drying step, thereby reducing overall operating costs of the process.

In alternative embodiments, the process used to encapsulate the composite PCMs is a fluidized bed process, e.g., the Wurster process (i.e. the Bottom Spray process) as described e.g., in US Patent no. 3,241 ,520, US Patent No. 3,253,944, and US Patent no. 3, 196,827. The Wurster process allows a fluidized material to be coated with high-quality, reproducible films (the process is generally used in the production of controlled-release, extended release, or delayed/enteric release pharmaceutical products). The process allows for the complete coating of the surface, thereby generating a fully encapsulated/contained particle.

In alternative embodiments of processes as provided herein, the Wurster process is used as a method of encapsulating the generated composite PCM particles comprising an adsorbent and a PCM wherein the PCM has been adsorbed in or onto to the porous structure, or macro-, micro- or nano- structured or equivalent, equivalent structure of the adsorbent. In alternative embodiments, the coating process is performed in coating vessel comprising a fluidized bed in the Wurster configuration, wherein the fluidized bed is comprised of a cylindrical product container, perforated air disc plate, coating partition, spray nozzle, and an expansion chamber. The perforated air distribution plate and partition organize the fluidization of the material through the partition or coating zone. A spray nozzle, mounted and centered at the bottom of the cylindrical product container, disperses fine particles of a coating agent that encounter the fluidized material in the coating zone. This process minimizes spray drying and allows a high coating uniformity and efficiency.

In alternative embodiments, the coating agent dispersed through the spray nozzle is a polymer. In alternative embodiments, the coating agent is a polymer selected from the group consisting of: waxes, water soluble polymers, and water in-soluble polymers. Specific coating agents that may be used in the encapsulation process include, without limitation, cellulose derivative polymers e.g. METHOCEL™, ETHOCEL™, CELLOSIZE™, or hydroxyethyl Cellulose, latex polymers e.g., polyvinylidene chloride (PVDC), acrylic polymers such as acrylic acid alkylesters, acrylic resins, acrylic emulsion resins, polyurethane dispersions, polyvinyl alcohol, colloidal silica dispersions, waxes such as carnauba wax, and equivalents thereof and combinations therof.

In alternative embodiments, the encapsulation process comprises multiple coating steps. In embodiments comprising multiple coating steps, the coating agent used in each step may be the same or different polymer. In alternative embodiments, the encapsulation process comprises two coating steps wherein the coating agent in the first coating step is a cellulose polymer, and the coating agent used in the second coating step is a polymer having exceptional oxygen and water vapor transmission rates to protect the cellulose coating, e.g. PVDC. In alternative embodiments, the secondary coating step allows for the use of multiple coating materials with desirable physical properties.

In alternative embodiments, the first coating step comprises the use of a coating material that is, e.g., water-soluble. In such embodiments, the secondary coating step may comprise a water-insoluble such that, if the PCM were to leak through the first coating layer, the second coating layer would prevent leakage of the PCM-comprising particles. Alternatively, the interior coating may be water-insoluble to prevent contact of the PCM with a water- soluble outer coating. In alternative embodiments, the interior coating is comprised of a material that is reactive in the presence of oxygen. In such embodiments, a second (outer) coating may be applied to the PCM-comprising particles has a low oxygen vapor transmission rate, thereby protecting the particles from oxygen damage.

In alternative embodiments the encapsulating agent is generated by dissolving the selected polymer in a solvent, e.g., an aqueous or non-aqueous solvent, or a mixture of multiple solvents. In alternative embodiments, the solvent can be, for example, acetone, toluene, an alcohol, methyl ethyl ketone, isopropyl acetate, CELLOSOLVE™ or other solvents based on alkyl ethers of ethylene glycol or propylene glycol, xylene butyl acetate, tetrahydrofuran (THF), an amide, a chlorohydrocarbon, an ester, an ether, a hydrocarbon, a ketone, a nitrile, a nitroparaffin, an oil or oil derivative, or a mixture thereof.

In alternative embodiments, the resulting coating material is then loaded into the encapsulation vessel wherein the composite PCM particles, having been loading into the product chamber of the encapsulation vessel, are fluidized using air. The fluidized composite PCM particles are then sprayed and coated with the coating agent thereby generating encapsulated composite PCM particles. As the composite PCM particles, having been coated by the encapsulating agent, dry, the solvent evaporates rapidly from the coating agent material, leaving only the polymer material on the outer surface of the composite PCM. This process can be repeated multiple times, increasing the thickness of the shell of the encapsulated composite PCM particles with each coating step.

In alternative embodiments, provided are Phase Change Material (PCMs) compositions and products of manufacture comprising an encapsulated composite PCM wherein the composite PCM comprises an adsorbent having a porous structure, or macro-, micro- or nano-structured or equivalent, structure and a PCM, wherein the PCM is absorbed into the porous structure, or macro-, micro- or nano-structured or equivalent, structure of the adsorbent, and methods for making and using them. In alternative embodiments, the Phase Change Material (PCMs) compositions and products of manufacture are used for thermal energy management and temperature stabilization in various applications such as materials for making or using: building; storage compartments or facilities; in insulation or construction materials; electronics and computers, automotive materials; airlines; boats; industrial applications and processes; weapons systems, packaging materials or containers; pharmaceuticals; cloth, fabrics and garments; and footwear, and other energy storage and temperature stabilization systems.

The present invention is further defined in the following Examples. It should be understood that these examples, while indicating preferred embodiments of the invention, are given by way of illustration only and are not to be construed as limiting in any manner. From the above discussion and these examples, one skilled in the art can ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.

EXAMPLES

Example 1 : Methods for making exemplary compositions: Composite PCM comprising GRIT-O-COBB™ adsorbent, Paraffin PCM

GRIT-O-COBB™ particles having a diameter of approximately 500 - 600 microns, were impregnated with a C24 paraffin PCM under vacuum conditions (i.e. the PCM was absorbed into the pores of the GRIT-O-COBB™ adsorbent). The resulting composite PCM particles were comprised of approximately 32% of the C24 paraffin as confirmed by Differential Scanning Calorimetry (DSC) analysis (Table 1 ). The composite particles comprising the GRIT-O-COBB™ and C24 were coated with an aqueous 2% METHOCEL E15 LV™ (a cellulose- based coating polymer) solution using a Freund-Vector (Marion, IA) MICRO FLO COATER™ in the Wurster configuration. After coating, a heat encapsulation test was performed at 70^°C for 4 hours to evaluate the encapsulation efficiency. The heat encapsulation test comprises placing an adequate coated sample on a chem-wipe. The chem-wipe with the coated composite PCM is placed on a hot plate with the temperature set 20^°C above the PCM's phase change temperature. If any visible oil spots are observed on the chem-wipe, the material is not truly encapsulated.

After 4 hours, no oil spots were observed on the chem-wipe. A free oil solvent extraction test was performed on the METHOCEL™ coated composite using hexane as the solvent. GC/MS analyzed the solution to determine the amount of the PCM extracted into the hexane. DSC analysis was used to approximately determine the coating percent, and Scanning Electron Microscopy (SEM) was performed on the samples to measure the shell thickness of various particle sizes.

Table 1 shows the DSC analysis for the pure C24 paraffin, GRIT-O-

COBB™ (Grit-O-Cobb) impregnated with C24 starting material, and coated sample. The C24 paraffin showed a melting point at 51 .4 ^°C, and a latent heat value of 258.5 J/g. After the absorption process, the starting material that consisted of the GRIT-O-COBB™ and C24 paraffin had a similar melting temperature (51 .3 ^°C) and a latent heat value (82.90 J/g) that was approximately 32% of the pure paraffin. Sample 8199, the final coated sample, produced a melting point at 51 .6 ^°C, and a latent heat value of 48.81 J/g.

Table 1. DSC Analysis of C24 paraffin, GRIT-O-COBB™ (500 - 600 micron particles) impregnated with the C24 paraffin starting material, and Methocel coated samples. Melt Peak Data

Sample Onset (°C) Melt (°C) Latent Heat (J/g)

C 24 51 .0 51 .4 258.5 C24 Paraffin

Starting Material 51 .0 51 .3 82.90 32.0 % PCM

8199 50.9 51 .6 48.81 41 .1 % Coating

The difference in the latent heat values between the starting material and sample 8199 indicated a coating shell thickness of approximately 41 .1 % of the total volume of the particle. This was calculated by calculating the percent change in latent heat value of the uncoated and coated particles: (82.90 J/g - 48.81 J/g) = 24.09 J/g/82.90 J/g ^* 100% = 41 .1 %.

To confirm that a shell material was present on the coated composite sample, SEM analysis was performed to measure the shell thickness of different particles; images were recorded using an TESCAN LYRA™ Focused Ion Beam (FIB) - FESEM (Elektronen-Optik-Service GmbH, Dortmund, Germany), and particle shell thicknesses (widths) were calculated by related software. The SEM images as shown in Figure 2 (FIG. 2) show the shell thickness varies in each particle, and varied from 37.70 to 49.71 microns (pm). For example, in the upper left image, the scribed lines illustrate a computer enhanced image of the width (thickness) of the particle shell, and the width was calculated by software and indicated as "D" (distance between the scribed lines), which for example in this image are 41 .07 pm and 44.27 pm. The free oil solvent extraction test revealed that 6% free oil was present in the hexane solution compared to a sample where all the C24 was extracted from the composite material.

Example 2: Methods for making exemplary compositions

GRIT-O-COBB™ particles, having a diameter of approximately 500 to 600 microns, were impregnated with a C24 paraffin (tetracosame) under vacuum conditions (i.e. the PCM was absorbed into the pores of the Grit-O- Cobb adsorbent). The resulting composite PCM particles were comprised of approximately 32% of the C24 paraffin confirmed by DSC analysis (Table 2). The composite particles consisting of GRIT-O-COBB™ and C24 were coated with a 3% METHOCEL™ E15 LV 60:40 (water: ethanol) solution using a Freund-Vector (Marion, IA) MICRO FLO COATER™ in the Wurster configuration. After coating, a heat encapsulation test was performed at 70 ^°C for 4 hours to evaluate the encapsulation efficiency. After 4 hours, no oil spots were observed on the chem-wipe. A free oil solvent extraction test was perform on the METHOCEL™ coated composite using hexane as the solvent.

Table 2. shows the DSC analysis for the pure C24 paraffin, GRIT-O- COBB™ impregnated with C24 starting material, and coated samples. The C24 paraffin showed a melting point at 51.4 ^°C and latent heat value of 258.5 J/g. After the absorption process, the starting material, which consisted of the GRIT- O-COBB™ and C24 paraffin had a similar melting temperature (51 .3 ^°C) and a latent heat value (82.90 J/g) that was approximately 32% of the pure paraffin. Sample 9312, the final coated sample, produced a melting point at 51 .7 ^°C and a latent heat value of 36.28 J/g. The difference in the latent heat values between the starting material and sample 9312 allowed the coating % to be calculated at approximately 56.2 %. The coating % was increased compared to Example 1 in order to decrease the amount of free oil.

Table 2. DSC analysis of C24 pure paraffin, GRIT-O-COBB™ containing 32% C24 paraffin, and METHOCEL™ coated samples.

SEM images were recorded (as discussed in Example 1 ) of Sample 9312 to measure the shell thickness of different particles shown in Figure 3 (FIG. 3). The METHOCEL™ polymer shell thickness shown in Figure 3 varies from between about 53 to 94 microns. Compared to the images shown in Example 1 , the shells' thickness have increased encapsulating the composite material.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

Claims

WHAT IS CLAIMED IS:

1 . A Phase Change Material (PCM)-comprising composition comprising a composite PCM, wherein the composite PCM is comprised of an adsorbent material having a plurality of pores or macro-, micro- or nano- structures or equivalents, and a Phase Change Material (PCM), wherein the PCM is absorbed into or onto the pores, macro-, micro- or nano-structures or equivalent structures, of the adsorbent material.

2. The Phase Change Material (PCM)-comprising composition of claim 1 , wherein the Phase Change Material (PCM) is encapsulated or coated, and optionally the encapsulated or coated composite PCM particles have a diameter in the range of between about 10 microns to 3 millimeters (10μ to 3 mm), or between about 5μ to 5 mm.

3. The Phase Change Material (PCM)-comprising composition of claim 2, wherein the composite PCM is encapsulated or coated by one or more layers of a polymer material.

4. The Phase Change Material (PCM)-comprising composition of claim 1 , wherein the adsorbent material is selected from the group consisting of: activated carbon, graphite, expanded graphite, fullers earth, perlite, diatomaceous earth, cellulose, fibers, silica, celite, wood pulp, corn stover, biomass, bentonite, vermiculite, gypsum, silicon dioxide, attapulgite, graphene oxide, aluminum oxide, cement, molecular sieves, zeolites, metal foams, kaolinite, chlorite, montomorillonite, muscovite, illite, cookeite, GRIT-O- COBB™, silicates, fumed silica, cenospheres, expanded clay aggregates, mica clays, smectite clays, polyacrylate and a combination thereof.

5. The Phase Change Material (PCM)-comprising composition of claim 1 , wherein the adsorbent material is a plastic.

6. The Phase Change Material (PCM)-comprising composition claim 5, wherein the plastic is selected from the group consisting of: high-density polyethylene (HDPE) or polyethylene high-density (PEHD), Low-density polyethylene (LDPE), Poly(methyl methacrylate) (PMMA) or acrylic glass or acrylic (e.g., PLEXIGLAS™, ACRYLITE™, LUCITE™, PERSPEX™), polystyrene, Ethylene-vinyl acetate (EVA) or poly(ethylene-vinyl acetate) (PEVA), poly(ethylene terephthalate) (PET), thermoplastic elastomers (TPEs) such as styrenic block copolymers (TPE-s), ethylene/butylene block copolymers, crystalline ethylene/butylene block copolymers, thermoplastic olefins (TPE-o), elastomeric alloys (TPE-v or TPV), thermoplastic polyurethanes (TPU), thermoplastic copolyester, thermoplastic polyamides, acrylonitrile butadiene styrene (ABS), polypropylene (PP) or polypropene, equivalents thereof and combinations thereof.

7. The Phase Change Material (PCM)-comprising composition of claim 1 , wherein the PCM is an organic or an inorganic material.

8. The Phase Change Material (PCM)-comprising composition of claim 1 , wherein the PCM is selected from the group consisting of: fatty acids, fatty acid derivatives, salt hydrates, fatty alcohols, glycols, paraffins, sugars, sugar alcohols, eutectics and combinations thereof.

9. A method for thermoregulating, thermal protecting or insulating a product of manufacture, a building, a storage compartment or facility; an insulation or construction material; electronics and computers, automotive materials; airplanes; boats; industrial machinery; weapons systems, packaging materials or containers; pharmaceuticals or drug storage or delivery devices; cloth, fabrics or garments; footwear, energy storage or temperature stabilization systems, comprising use of or incorporation of a Phase Change Material (PCM)-comprising composition of any of claims 1 to 8.

10. A product of manufacture, a building, a storage compartment or facility; an insulation or construction material; electronics and computers, automotive materials; airplanes; boats; industrial machinery; weapons systems, packaging materials or containers; pharmaceuticals or drug storage or delivery devices; cloth, fabrics or garments; footwear, energy storage or temperature stabilization systems, comprising use of or incorporation of a Phase Change Material (PCM)-comprising composition of any of claims 1 to 8.