Compressed aerogel composite material and its manufacturing method

Abstract

The present disclosure relates to a method of making an aerogel composite, the method including compressing an aerogel composite, the aerogel composite including a gel dispersed around a reinforcing component. The method further includes heating the aerogel composite. The method further results in producing a compressed and heated aerogel composite, the produced aerogel composite including a plurality of pores, the majority of which have a diameter less than 50 nm.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 415,897, entitled "COMPRESSED AEROGEL COMPOSITE AND METHOD OF MAKING," filed October 13, 2022, the disclosure of which is incorporated herein by reference in its entirety. [Background technology]

[0002] To address some thermal isolation issues where insulating core materials experience high pressures, low-density materials have been developed. For example, polymer materials are blended with hollow glass microspheres to create syntactic foams, which are typically very stiff and compression-resistant. Syntactic materials are well known as insulators for underwater gas and gas pipelines and supporting equipment. However, syntactic materials are relatively inflexible and exhibit high thermal conductivity compared to flexible aerogel composites (aerogel matrix reinforced with fibers).

[0003] Aerogels are a class of materials based on their structure: low density, open cell structure, and large surface area (900 m 2 / g or greater), and submicron-scale pore sizes. Supercritical and subcritical fluid extraction techniques are commonly used to extract solvents from the fragile cells of the material. A variety of different aerogel compositions, both organic and inorganic, are known in the art. Inorganic aerogels are generally based on metal alkoxides and include materials such as silica, zirconia, titania, alumina, carbides, and many others. Organic aerogels can include carbon aerogels and polymer aerogels, such as polyimide aerogels. Summary of the Invention

[0004] The present disclosure relates to a method of making an aerogel composite, the method including compressing an aerogel composite, the aerogel composite including a gel dispersed around a reinforcing component. The method further includes heating the aerogel composite. The method further results in producing a compressed and heated aerogel composite, the produced aerogel composite including a plurality of pores, the majority of which have a diameter less than 50 nm.

[0005] The present disclosure further relates to a method of making an aerogel composite, the method including compressing an aerogel composite, the aerogel composite including silica gel dispersed around a reinforcing component including polyethylene terephthalate fibers. The method further includes heating the aerogel composite to a temperature above the glass transition temperature of polyethylene, polyacrylonitrile, polyacrylonitrile oxide, polyethylene terephthalate, or a mixture thereof. The method further results in producing a compressed and heated aerogel composite, the produced aerogel composite including a plurality of pores, the majority of which have a diameter less than 50 nm.

[0006] The present disclosure further relates to a compressed aerogel composite, which includes a gel including a metal oxide compound dispersed around a reinforcing component, the aerogel composite including a plurality of pores, the majority of which have a diameter less than 50 nm, and a thickness of the aerogel composite less than about 0.6 mm.

[0007] The present disclosure further relates to a compressed aerogel composite, which includes a gel including silica dispersed around a polyethylene terephthalate fiber-reinforced component, the aerogel composite including a plurality of pores, the majority of which have a diameter less than 50 nm.

[0008] The drawings illustrate various aspects of the present disclosure by way of example, but not by way of limitation. [Brief explanation of the drawings]

[0009] [Figure 1] 1 illustrates a compaction mechanism in which a hydraulic press is used to densify the aerogel composite. [Figure 2] Sequential compression scheme for densification of aerogel composites. [Figure 3] 1 is a graph showing the thermal conductivity of the gel for the aerogel composite of Example 1 at different levels. [Figure 4] 1 is a graph showing the thermal performance response within the composite aerogel of Example 1. [Figure 5] 1 is a graph showing the thermal conductivity of the composite aerogel of Example 1 at various temperatures. [Figure 6A] 1 is a graph illustrating the decrease in thermal conductivity of composite aerogels. [Figure 6B] 1 is a graph showing the average pore size of the composite aerogel of Example 1 at various degrees of permanent set. [Figure 7] 1 is a graph showing pore size distribution in the composite aerogel of Example 1 at various degrees of permanent set. [Figure 8] 1 is a graph illustrating the limited percentage of applied strain maintained in an aerogel composite upon application of compressive strain. [Figure 9A] Illustrates that both lower silica density and higher compressive strain in aerogel composites are associated with higher plastic strain in the aerogel composites. [Figure 9B] This demonstrates that the hydrophobic component (covalently bonded to the silica aerogel in the reinforced silica aerogel composite) is another parameter that can alter the amount of reinforced plastic deformation in the aerogel composite in response to compressive strain. DETAILED DESCRIPTION OF THE INVENTION

[0010] Reference will now be made in detail to certain aspects of the disclosed subject matter, examples of which are illustrated in part in the accompanying drawings. While the disclosed subject matter will be described in conjunction with the enumerated claims, it will be understood that the exemplified subject matter does not limit the claims to the disclosed subject matter.

[0011] definition Throughout this document, values ​​expressed in range format should be interpreted flexibly as if each numerical value and subrange were explicitly recited, to include not only the numerical values ​​explicitly recited as the limits of that range, but also all individual numerical values ​​or subranges within that range. For example, a range of "about 0.1% to about 5%" or "about 0.1% to 5%" should be interpreted to include not only about 0.1% to about 5%, but also individual values ​​(e.g., 1%, 2%, 3%, and 4%) and subranges within the stated range (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%). The term "about X to Y" has the same meaning as "about X to about Y" unless otherwise indicated. Similarly, the term "about X, Y, or about Z" has the same meaning as "about X, about Y, or about Z" unless otherwise indicated.

[0012] In this document, the terms "a," "an," or "the" are used to include one or more unless the context clearly dictates otherwise. The term "or" is used to refer to a non-exclusive "or" unless otherwise indicated. The statements "at least one of A and B" or "at least one of A or B" have the same meaning as "A, B, or A and B." In addition, it should be understood that phrases and terms employed herein and not otherwise defined are for descriptive purposes and should not be considered limiting. Any use of section headings is intended to aid in the reading of the document and is not to be construed as limiting. Information associated with a section heading may occur within or outside that particular section. All publications, patents, and patent documents referenced herein are incorporated herein by reference in their entirety, as if individually incorporated by reference. In the event of any inconsistent usage between this specification and those documents incorporated by reference, the usage in the incorporated references should be considered supplementary to the usage in this specification. In the case of irresolvable discrepancies, the usage herein will control.

[0013] In the methods described herein, unless a temporal or operational sequence is explicitly recited, acts may be performed in any order without departing from the principles of the present disclosure. Moreover, certain acts may be performed simultaneously unless express claim language dictates otherwise. For example, a claimed act of performing X and a claimed act of performing Y may be performed simultaneously in a single operation, and the resulting steps are included in the context of the steps recited in the claims.

[0014] As used herein, the term "about" allows for a degree of variation in a value or range, for example, within 10%, within 5%, or within 1% of a stated value or boundary of a stated range, and includes the exact stated value or range herein.

[0015] The term "substantially" as used herein includes mostly, or primarily, at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999% or more, or 100%.

[0016] As used herein, the term "substantially free of" can mean absence, or the amount of material present does not affect the material properties of a composition that includes the material, and can include, for example, from about 0 wt. % to about 5 wt. % of the composition, or from about 0 wt. % to about 1 wt. %, or about 5 wt. % or less, or about 4.5 wt. %, 4, 3.5, 3, 2.5, 2, 1.5, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.01, or about 0.001 wt. % or less, or about 0 wt. %.

[0017] As used herein, the term "compression set" refers to the amount of permanent deformation that occurs when a material is compressed to a particular deformation for a specified time at a particular temperature.

[0018] Aerogel composite synthesis The polymers described herein can be terminated in any suitable manner. In some embodiments, a suitable polymerization initiator is selected from the group consisting of substituted or unsubstituted (C1-C6) alkyl groups interrupted by 0, 1, 2, or 3 groups independently selected from -H, -OH, and -O-. 20 ) hydrocarbyl (e.g., (C-C 10 ) alkyl or (C6-C 20 )aryl), substituted or unsubstituted -NH- and -S-, poly(substituted or unsubstituted (C-C 20 )hydrocarbyloxy), and poly(substituted or unsubstituted (C-C 20 and )hydrocarbylamino).

[0019] The embodiments presented herein allow for the preparation of improved aerogel composite structures with low thermal conductivity at increased density, while creating optimal pore size and overall thickness, as well as controlling thermal conductivity, maximum stress at 50% strain, and compression settings of heated and compressed (as opposed to only compressed) aerogels. This is largely due to the disclosed process, which includes compressing the aerogel composite and heating the aerogel composite.

[0020] Densified aerogels, particularly mechanically densified aerogel composites, can be formed from flexible (undensified) precursors. Various flexible layers, including flexible fiber-reinforced aerogels, can be easily combined and formed to yield a preform that, when mechanically compressed along one or more axes, yields a body that is resistant to compression along any of those axes. These densified aerogel bodies exhibit much better thermal insulation values ​​than syntactic foams. Other composite aerogel properties that benefit from mechanical densification include increased flexural strength and modulus.

[0021] For convenience, the alcogel route to forming inorganic aerogels is used below to illustrate the disclosure, but this is not intended to limit the disclosure to any particular type of aerogel and / or method of preparation. The disclosure is also applicable to other inorganic, inorganic / organic, and organic aerogels and preparation methods.

[0022] Aerogels and aerogel composites suitable for compression and heating can take a variety of forms, including particle-reinforced aerogels, fiber-reinforced aerogels, or unreinforced aerogels, any one of which comprises an organic aerogel matrix, an inorganic aerogel matrix, or a hybrid aerogel matrix. An exemplary form is a two-phase aerogel composite, where a first phase comprises a low-density aerogel and a second phase comprises a reinforcing material.

[0023] In a simple form of fiber-reinforced aerogel composite, fibrous materials are embedded within a matrix material for various reasons, including improved mechanical performance. The matrix material can be prepared via sol-gel processing, resulting in a polymer network (including inorganic, organic, or inorganic / organic hybrids). The fibrous materials, combined with the sol prior to the point of polymer gelation during sol-gel processing, reinforce the matrix material. The aerogel matrix of the preferred precursor material for the present disclosure can be organic, inorganic, or a mixture thereof. Wet gels used to prepare aerogels can be prepared via any of the gel-forming techniques known to those skilled in the art, examples of which include adjusting the pH and / or temperature of dilute metal oxide sols to the point where gelation occurs (R.K. Iler, Colloid Chemistry of Silica and Silicates, 1954, chapter 6; R.K. Iler, The Chemistry of Silica, 1979, chapter 5; C.J. Brinker and G.W.Scherer, Sol-Gel Science, 1990, chapters 2 and 3, all incorporated by reference). Examples of materials for forming inorganic aerogels are metal oxides such as silica alumina, titania, zirconia, hafnia, yttria, and vanadia. In some embodiments, gels can be formed primarily from alcoholic solutions of hydrolyzed silicate esters due to their ready availability and low cost.

[0024] One synthetic route for the formation of inorganic aerogels is the hydrolysis and condensation of a suitable metal alkoxide. The most suitable metal alkoxides are those having approximately 1 to 6 carbon atoms, with each alkyl group having from 1 to 4 carbon atoms. Specific examples of such compounds include tetraethoxysilane (TEOS), tetramethoxysilane (TMOS), tetra-n-propoxysilane, aluminum isopropoxide, aluminum sec-butoxide, cerium isopropoxide, hafnium tert-butoxide, magnesium aluminum isopropoxide, yttrium isopropoxide, titanium isopropoxide, and zirconium isopropoxide. In the case of silica precursors, these materials can be partially hydrolyzed and stabilized at low pH as polysilicic acid ester polymers, such as polydiethoxysiloxane. These materials are commercially available in alcohol solutions. Prepolymerized silica precursors are also preferred for the aerogel composites described herein.

[0025] Some variables in the inorganic aerogel formation process include the type of alkoxide, solution pH, and alkoxide / alcohol / water ratio. Control of these variables can allow for control of the growth and aggregation of matrix seeds throughout the transition from the "sol" state to the "gel" state. While the properties of the resulting aerogel are strongly influenced by the pH and molar ratio of the reactants of the precursor solution, any pH and any molar ratio that allows for gel formation can be used in this embodiment.

[0026] Generally, the solvent for these steps is a lower alcohol, e.g., an alcohol having 1 to 6 carbon atoms, preferably 2 to 4 carbon atoms, although other liquids can be used as known in the art. Examples of other useful liquids include, but are not limited to, ethyl acetate, ethyl acetoacetate, acetone, and dichloromethane.

[0027] While any of the following methods can be used to produce precursor aerogel composite parts, the method that allows for the lowest density and / or best thermal insulation of the part is desirable. For example, in a first alternative implementation of gel production, a water-soluble basic metal oxide precursor can be gelled by acidification in water to produce a hydrogel. Sodium silicate has been widely used for this purpose. Salt by-products can be removed from the silica precursor by ion exchange and / or by subsequently washing the formed gel with water. Water removal from the gel pores can be carried out via exchange with a polar organic solvent such as ethanol, methanol, or acetone. The resulting dried aerogel has a structure similar to that formed directly by supercritical extraction of a gel produced in the same organic solvent. A second alternative method involves reducing damaging capillary pressure at the solvent / pore interface by chemical modification of the matrix material in its wet gel state via conversion of surface hydroxyl groups to trimethylsilyl ethers (see, e.g., U.S. Pat. No. 5,877,100) to enable drying of the aerogel material at temperatures and pressures below the critical point of the solvent.

[0028] Methods for drying gels to produce aerogels or xerogels are known. Kistler (J. Phys. Chem., 36, 1932, 52-64) describes a drying process in which the gel solvent is maintained above its critical pressure and temperature. Due to the absence of any capillary forces, such supercritical drying maintains the structural integrity of the gel. U.S. Pat. No. 4,610,863 describes a process in which the gel solvent is exchanged with liquid carbon dioxide and then dried under conditions in which the carbon dioxide is in a supercritical state. Such conditions are milder than those described by Kistler. U.S. Pat. No. 6,670,402 teaches drying via rapid solvent exchange within a wet gel using supercritical CO2, rather than liquid CO2, by injecting supercritical CO2 into an extractor preheated and prepressurized to or above substantially supercritical conditions to produce an aerogel. U.S. Patent No. 5,962,539 describes a process for obtaining aerogels from polymeric materials in sol-gel form in an organic solvent by exchanging the organic solvent for a fluid having a critical temperature below the temperature of polymer decomposition and supercritically drying the fluid / sol-gel. U.S. Patent No. 6,315,971 describes a process for making gel compositions, which involves drying a wet gel containing a gel solid and a desiccant to remove the desiccant under conditions sufficiently dry to minimize gel shrinkage during drying. U.S. Patent No. 5,420,168 also describes a process for producing resorcinol / formaldehyde aerogels using a simple air-drying procedure. U.S. Patent No. 5,4565,142 describes a process in which the gel surface is modified to make it more hydrophobic and strong so that it can resist any collapse of structure during ambient or subcritical drying. The surface-modified gel is dried at ambient pressure or below the critical point (subcritical drying). The product resulting from such ambient pressure or subcritical drying is often referred to as a xerogel.

[0029] Organic aerogels can be fabricated from polyacrylates, polystyrene, oxidized polyacrylonitrile, polyacrylonitrile, polyurethanes, polyimides, polyfurfural alcohol, phenol furfuryl alcohol, melamine formaldehyde, resorcinol formaldehyde, cresol formaldehyde, phenol formaldehyde, polyvinyl alcohol dialdehyde, polycyanurates, polyacrylamides, various epoxies, agar, and agarose (see, for example, C.S.A. Ashley, C.J.Brinker, and D.M. Smith, Journal of Non-Crystalline Solids, volume 285, 2001).

[0030] Suitable materials for use in preparing aerogels for low-temperature applications include non-refractory metal alkoxides based on oxide-forming metals. Examples of such metals are silicon and magnesium, as well as mixtures thereof. For higher temperatures, suitable alkoxides are generally refractory metal alkoxides that form oxides, such as mixtures of zirconia and yttria, with zirconia, yttria, hafnia, alumina, titania, and ceria. Mixtures of non-refractory metals with refractory metals, such as mixtures of silicon and / or magnesium with aluminum, can also be used. The advantage of using more than one metal oxide matrix material for the aerogel structure is enhanced IR opacification, achieved by providing chemical functional groups that absorb radiation over a wide range of wavelengths. Additionally, finely dispersed dopants, such as carbon black, titania, iron oxide, silicon carbide, molybdenum silicide, manganese oxide, and polydialkylsiloxanes, where the alkyl group contains 1 to 4 carbon atoms, can be added to improve thermal performance at higher temperatures by increasing the opacity of the molded article to IR transmission. Suitable amounts of such dopants generally range from about 1 to 40%, or about 2 to 10%, by weight of the finished composite material.

[0031] In the fiber-reinforced aerogel composites described above, the reinforcing component can be a fiber reinforcement that is a lofty fiber structure (batting or web), but can also include individual, randomly oriented, short microfibers, and woven or nonwoven fabrics. More specifically, suitable fiber reinforcements are based on either organic (e.g., thermoplastic polyester, high-strength carbon, aramid, high-strength oriented polyethylene, etc.) fibers, low-temperature inorganic (e.g., metal oxide glass such as E-glass) fibers, or refractory (e.g., silica, alumina, aluminum phosphate, aluminosilicate, etc.) fibers. Generally, the fibers can be inorganic fibers, organic fibers, particles, metal fibers, metal mesh, or mixtures thereof.

[0032] In some particular examples, the fiber can be polyethylene terephthalate. The polyethylene terephthalate can be a composite polyethylene terephthalate fiber comprising an inner core and an outer core, the inner core having a higher melting temperature than the outer core.

[0033] In some embodiments, inorganic (e.g., alumina, metal) or organic (e.g., melamine) foams can be used in the sol chemistries described above to create foam-reinforced aerogel composites. In the context of fiber-reinforced aerogel composites, the reinforcing foams can be combined and compounded into foam-reinforced composites using any of the sol chemistries and processing techniques described above.

[0034] The reinforcing component can be in the range of about 5 wt% to about 75 wt% of the aerogel composite, about 25 wt% to about 50 wt%, or about 30 wt% to about 40 wt% of the aerogel composite.

[0035] Mechanical loads experienced by the composite aerogel can be transmitted through the durable textile fiber layer to fasteners and other structures. Mechanical loads may be experienced first by the fiber layer and then transferred to the aerogel composite. An example of this is securing the aerogel composite on a vehicle chassis or vehicle component (e.g., interior body panels, firewall, engine mount, battery / battery pack housing) capable of withstanding forces to act as a thermal barrier. This aspect of the process for producing densified nanoporous bodies does not require densification to occur prior to installation in the application environment. Non-mechanically densified aerogel composites can be secured to the body via fastening means (adhesives, tape, fasteners, etc.), followed by physical compression to mold the now mechanically densified nanoporous body into the shape of the molded article. This is a significant advantage for producing insulated or protected molded articles within the smallest possible volume and cross-sectional area.

[0036] For the aerogel composites described above, density increase can be defined in the broadest sense in which the density increase can be measured; for example, the density of the aerogel composite can increase by 2 to 20 times or 3 to 10 times relative to the uncompressed and unheated aerogel composite. In these embodiments, the density referenced is the "envelope" density of the reinforced aerogel composite. Other types of density measurements, such as the "skeletal" density of unreinforced aerogel material, can be described in other contexts.

[0037] The resulting composite materials can be flexible, durable, have low thermal conductivity, and have good resistance to sintering. The performance of aerogel composites can be substantially enhanced by incorporating randomly distributed microfibers into the composite, particularly microfibers that help resist sintering, increase durability, and reduce dusting. The effect of short fiber reinforcement (microfibers) on composite performance depends on several variables, including fiber alignment, diameter, length, aspect ratio (fiber length / fiber diameter), strength, strain to failure, coefficient of thermal expansion, and interfacial strength between the fiber and matrix. Microfibers are incorporated into composites by dispersing them in a gel precursor liquid and then using that liquid to infiltrate a lofty batting.

[0038] Suitable microfibers useful herein typically range in diameter from 0.1 to 100 μm, have a high aspect ratio (L / d>5 or L / d>100), and are relatively uniformly distributed throughout the composite. Higher aspect ratios improve composite performance, so the longest possible microfibers are desirable. However, the length of the fibers used herein is constrained to avoid (or at least minimize) any filtration by the selected lofty batting when the microfiber-containing gel precursor is poured into the batting. Microfibers should be short enough to minimize filtration by the lofty batting, yet long enough to have the greatest possible effect on the thermal and mechanical performance of the resulting composite. Microfibers can have a thermal conductivity of 200 mW / mK or less to facilitate the formation of low-thermal-conductivity aerogel composites.

[0039] When microfibers are dispersed in the sol, they often settle quickly. To overcome this problem, a suspending or dispersing agent that does not adversely affect gel formation should be added to the sol. Suitable suspending / dispersing agents include solutions of high molecular weight block copolymers with pigment-affinity groups (Disperbyk-184 and 192 from BYK-Chemie). The agent must be effective at least during the period between the dispersion of the microfibers in the gel precursor and the gelation of the sol.

[0040] The amount, type, and / or size, as well as aspect ratio, of microfibers used within a particular aerogel composite can be varied to fulfill a particular task. For example, an application may involve insulating regions of different temperatures using a continuous aerogel composite, and the composite may be manufactured so that more microfibers are present in areas of the composite in contact with the higher temperature regions. Similarly, different microfibers (e.g., different materials, aspect ratios, sizes) may be incorporated within such areas for best insulating performance. Such microfiber modification may be achieved by using various suspending agents and / or microfibers to anchor the microfibers to the composite at different rates and, therefore, within different locations.

[0041] Suitable fibrous materials for forming both the lofty batting and the xy-oriented tensile reinforcement layer include any fiber-forming material. In particular, suitable materials include fiberglass, quartz, polyester (PET), polyethylene, polypropylene, polybenzimidazole (PBI), polyphenylene benzobisoxazole (PBO), polyetheretherketone (PEEK), polyarylate, polyacrylate, polytetrafluoroethylene (PTFE), polymetaphenylenediamine (Nomex), polyparaphenylene terephthalamide (Kevlar), ultra-high molecular weight polyethylene (UHMWPE), e.g., Spectra®, novoloid resin (Kynol), polyacrylonitrile (PAN), PAN / carbon, and carbon fiber.

[0042] The aerogel composite can include one or more additives. For example, the aerogel composite can include boron carbide [BC], diatomaceous earth, manganese ferrite, MnO, NiO, SnO, AgO, BiO, carbon black, titanium oxide, titanium iron oxide, aluminum oxide, zirconium silicate, zirconium oxide, iron (II) oxide, iron (III) oxide, manganese dioxide, titanium iron oxide (ilmenite), chromium oxide, SiC, TiC, or WC, TiOSO, TiOCl, or mixtures thereof. The concentration of the additive can range from about 0.05 wt% to about 10 wt% of the aerogel composite, or from about 1 wt% to about 7 wt% of the aerogel composite.

[0043] Aerogels processed by simultaneous heating and compression In various embodiments, aerogel compositions that are simultaneously heated during compression produce composites with lower thermal conductivities and more uniform thicknesses than comparable composites that are not compressed at all and / or heated during the compression operation. More specifically, composite aerogel embodiments that are heated during compression have a standard deviation in average thickness that can be as low as one-half or one-quarter of that of comparable materials that are compressed but not heated. Additionally, in various embodiments, aerogel compositions that are simultaneously heated during compression produce composites with higher maximum stresses at 50% strain than comparable composites that are not compressed at all and / or heated during the compression operation.

[0044] Additionally, in various embodiments, aerogel compositions that are simultaneously heated during compression produce composites that have higher compressive strain values ​​than comparable composites that are not compressed at all and / or not heated during the compression operation.

[0045] Additionally, in various embodiments, aerogel compositions that are simultaneously heated during compression produce composites that have higher compression set points than comparable composites that are not compressed at all and / or not heated during the compression operation.

[0046] As shown in the examples, in many applications, the standard deviation for the obtained values ​​is lower than that for comparable aerogel composites that have only been compressed (e.g., not compressed and heated). This means that the fabricated aerogel composites can not only have their desired properties, but also have a degree of control over those properties that cannot be achieved by compression alone. This degree of control is advantageous for overall processing of the aerogel composite and for certain applications, such as in electric vehicle battery compartments or other devices with low tolerances for error. For example, when using automated assembly systems such as industrial robots to assemble multi-component battery packs, dimensional variations can cause manufacturing system failures. In some examples, poor dimensional control can result in electrolyte pooling (from insufficient external pressure on a lithium-ion battery cell due to parts that are too thick) or cell rupture (from excessive external pressure on a lithium-ion battery cell due to parts that are too thick).

[0047] The aerogel composite can be formed using a hydraulic press.

[0048] FIG. 1 illustrates a typical hydraulic press that can be used for mechanical pressing and has two press plates 100, in which a compressive force F is applied to the press plates by at least one hydraulic press cylinder unit at the location where the cylinder unit is connected to the press plates. The press plates can be laterally guided and restrained by a counter-support device. Alternatively, one press plate can be fixed. Thus, an aerogel 102 is positioned between the press plates 100 and then compressed.

[0049] In another aspect, densification is achieved through localized compression provided by the successive action of counter-rotating rollers having a clearance (between the rollers) substantially less than the thickness of the uncompressed composite aerogel. Thus, passage of the aerogel composite through said clearance compresses the aerogel composite, thereby resulting in a substantial density increase.

[0050] The aerogels discussed previously can also be densified by passing them between at least one pair of rollers to form a sheet having a reduced but more uniform thickness and an overall flatter surface. The term "densification" refers to the process of compressing the aerogel and / or aerogel composite. In this particular embodiment, compression is accomplished by passing the aerogel and / or aerogel composite between one or more sets of rollers to densify the resulting product. When a series of rollers is used, the roller pairs can have successively narrower gaps between them and can also have various patterns on their surfaces to produce increasingly dense aerogel and / or aerogel composite materials.

[0051] The roller can be treated to prevent adhesion between the aerogel and / or aerogel composite and the roller. This can be accomplished by coating the roller with a non-stick substance, polishing the roller, heating the roller to create a water vapor barrier, cooling the roller to create condensation, or a combination thereof.

[0052] In one embodiment, it is desirable to "densify" the aerogel or aerogel composite by passing it between at least one pair of rollers, as shown in FIG. 2, with the goal being to improve the thermal and / or mechanical performance of the aerogel or aerogel composite through densification. In some embodiments, the densification step only densifies the aerogel or aerogel composite by a small amount. In other cases, the densification process substantially densifies the aerogel or aerogel composite. In cases where it is desirable to highly densify the aerogel or aerogel composite, it is often necessary to densify the aerogel or aerogel composite in steps in which the aerogel or aerogel composite is passed through several pairs of rollers, each having an increasingly narrow gap distance between them.

[0053] Reference should now be made to FIG. 2, which shows one embodiment in which at least one pair of rollers 202 is employed during the densification step. It should be understood that more than one pair of rollers may be necessary to achieve the desired densification. When more than one pair of rollers is employed, the rollers within each of the roller pairs may have similar diameters, although in some cases it may be preferable to use a smaller diameter roller in combination with a larger diameter. As seen in FIG. 2, a set or pair of rollers typically includes two individual rollers 202 positioned adjacent to one another with a predetermined gap distance between them. The gap distance between the two individual rollers corresponds to the desired densification 204 of the aerogel 200 after it passes between the pair of rollers.

[0054] The press or rollers used can exert pressures in the range of less than, equal to, or greater than about 500 kPa to about 1000 kPa, about 700 kPa to about 1000 kPa, about 500 kPa, 600, 700, 800, 900, or about 1000 kPa. The pressure can be constant throughout the process, or it can be variable. The amount of time that pressing is carried out can range from about 0.2 hours to about 24 hours, from about 2 hours to about 15 hours, or from about 5 hours to about 10 hours.

[0055] In an embodiment of the present disclosure, the aerogel composite is heated during compression. The application of heat simultaneously with the application of pressure is indicated by "D" in Figures 1 and 2. By way of non-limiting example, the aerogel composite can be heated to a temperature ranging from about 80°C to about 700°C, about 90°C to about 650°C, or 500°C to about 600°C, or about 90°C to about 110°C. Heating can occur simultaneously with compression or subsequent compression. Heating can also occur at a constant temperature or across a temperature gradient. Heating can be a single cycle or multiple heating cycles. Typically, the compression device itself is heated, which provides heat to the aerogel composite.

[0056] As described herein above, it has been discovered that the size of the pores within an aerogel composite can be carefully controlled when the aerogel composite is simultaneously heated and compressed. In particular, a majority (greater than 50% of the total number of pores) can have a large (e.g., largest) diameter, measured perpendicular to the plane of the major surface of the aerogel composite, that is less than about 50 nm, less than about 40 nm, less than about 30 nm, less than about 20 nm, about 10 nm to about 50 nm, or about 20 nm to about 40 nm. Pores in these ranges can provide optimal low thermal conductivity. That is, pores in these ranges can rapidly reduce the capacity for convective heat transfer through the pores. Simply, the pores are too small to allow this. However, the pores are not small enough to densify the aerogel to a degree that would predict increased conductive heat transfer.

[0057] Individual pores can take on many different shapes or profiles. For example, the pores can have an elongated profile. An elongated profile can be understood as being a generally non-spherical or elliptical profile. In some embodiments, the profile of an individual pore may be circular before compression and then elongated during compression.

[0058] Following pressing and heating, the average thickness of the final aerogel composite ranges from about 0.1 mm to about 1.5 mm, about 0.1 mm to about 0.6 mm, 0.1 mm to about 0.5 mm, or about 0.2 mm to about 0.4 mm. The strain of the aerogel composite following its production ranges from about 5% to about 40%, about 10% to about 30%, or about 15% to 20% of the total thickness of the aerogel composite. As understood herein, "strain" refers to the deformation from the heat-treated, compressed aerogel composite.

[0059] The thermal conductivity of the final aerogel composite can be in the range of about 13 milliwatts per meter-Kelvin (mW / mK) to about 60 mW / mK, about 15 mW / mK to about 55 mW / mK, about 20 mW / mK to about 50 mW / mK, about 25 mW / mK to about 45 mW / mK, or about 30 mW / mK to about 40 mW / mK.

[0060] Without intending to be bound by any theory, it is believed that heating in addition to compression enables the formation of the disclosed aerogel composites having the disclosed thickness, pore size, and thermal conductivity. In particular, it has not been believed possible to achieve these values ​​by simply compressing the aerogel composite without the simultaneous application of heat. This is because reinforcing components (e.g., fibrous reinforcing components) tend to plastically deform to compensate in response to the applied stress and / or elastically release some / most of the applied compression. The compression release (equivalently, elasticity in the composite) may result from resilience caused by twist in the yarn reinforcement, the natural resilience / elasticity of nonwoven fabrics from the available and variable free space between fibers that allows fiber movement in response to the applied compressive stress, and / or the natural resilience / elasticity of woven fabrics. As recognized by the present disclosure, applying a heating step simultaneously with the compression force overcomes these challenges. Advantages of combining heating and compression can include greater precision, consistency, and uniformity in reinforced aerogel thickness when simultaneously heated and compressed relative to the same reinforced aerogel composite compressed without heating.

[0061] Without intending to be bound by any theory, a mechanism that may contribute to these advantages is that heating the reinforcing component above its glass transition temperature (for the polymer) or other activation temperature allows it to remain compressed after release of pressure. As an example, the reinforcing component may include a composite fiber (e.g., polyethylene terephthalate) comprising an inner core and an outer core, the melting temperature of the inner core being higher than the melting temperature of the outer core. In such a structure, the aerogel composite may be heated above the melting temperature of the outer core, such that the inner core remains intact while the outer core adheres to the gel. Another explanation, without intending to be bound by any theory, is that the advantageous properties may be achieved because heat causes reactions between surface groups covalently bonded to the aerogel surface (e.g., silanol condensation in hydrophobic materials) that prevent the release of applied strain within the aerogel.

[0062] Without intending to be bound by any theory, with particular reference to improvements in thermal conductivity relative to compressed-only aerogel composites, altering the pore size distribution may be beneficial. Reducing the proportion of macropores (pores with diameters greater than 50 nm) may further reduce the thermal conductivity of the composite by reducing the ability of gas molecules to diffuse through the porous aerogel structure. In addition, beyond what is described herein, compressing aerogel composites may result in an undesirable increase in the density of the aerogel, which increases the number of solid conductive paths within such aerogels.

[0063] As shown in the examples herein, aerogels subjected exclusively to compression can provide adequate properties. However, compression and heating improve the properties of the aerogel overall. As also shown, the thickness of the aerogel can be carefully controlled to result in an aerogel with desired properties. The control or thickness and resulting properties of aerogels subjected to both compression and heating, relative to corresponding aerogels that are compressed only, is unexpected to one skilled in the art.

[0064] Example Various aspects of the present disclosure can be better understood by reference to the following examples, which are provided by way of illustration and not by way of limitation. The present disclosure is not limited to the examples given herein.

[0065] Example 1 Composite aerogels with a thickness of 4.5 mm, SiC gel, and quartz fiber reinforced components aged with 0.1 M TMS were fabricated, and various properties of the composite aerogels were investigated.

[0066] Figure 3 is a graph showing the thermal conductivity of gel for aerogel composites at different levels of compression. As shown, the thermal conductivity at high temperatures decreases when the aerogel composite is compressed to densities between 0.034 g / cc and 0.079 g / cc.

[0067] 4 is a graph showing thermal performance versus aerogel for the composite aerogel of Example 1. As shown, the thermal conductivity of the aerogel composite decreases when exposed to a pressure of 4300 kPa.

[0068] 5 is a graph showing the thermal conductivity at various temperatures of the composite aerogels of Example 1. As shown, the aerogel composites compressed at 11% and 31% strains showed an improvement in thermal conductivity relative to the uncompressed aerogel composites.

[0069] FIG. 6A is a graph illustrating the decrease in thermal conductivity of composite aerogels with permanent set of less than 41%.

[0070] 6B is a graph showing the average pore size of the composite aerogel of Example 1 at various degrees of permanent strain. As shown, the pore size can be controlled, but above 31% strain, the pores can become too small.

[0071] 7 is a graph showing the pore size distribution in the composite aerogel of Example 1 at various degrees of permanent set. As shown, as the permanent set increases, the average pore size decreases.

[0072] FIG. 8 is a graph illustrating the limited percentage of applied strain that is maintained in an aerogel composite when a compressive strain is applied.

[0073] FIG. 9A illustrates that both lower silica density and higher compressive strain in the aerogel composite are associated with higher plastic strain in the aerogel composite.

[0074] FIG. 9B illustrates that hydrophobic components (covalently bonded to the silica aerogel in the reinforced silica aerogel composite) can alter the amount of plastic deformation sustained within the aerogel composite in response to compressive strain.

[0075] Example 2 Composite aerogels containing octadecyltrimethoxysilane on partially oxidized polyacrylonitrile were fabricated. The initial density of the aerogel was 0.0825 g / cc with an initial thickness of 2 mm. Density refers to grams of silica per unit volume of gel. The target thickness following compression and / or heating was 1.45 mm.

[0076] The aerogel was initially compressed without heating, achieving a thickness of 1.716 mm with a thickness standard deviation of 0.0998 mm. When the aerogel was compressed and heated, the thickness was 1.62 mm with a thickness standard deviation of 0.05 mm. This indicates that compression and heating together provide a suitable thickness with some control in achieving the target thickness, as well as lower variability in thickness as indicated by a standard deviation that is approximately half that of the unheated, compressed sample. Reduced dimensional (e.g., thickness) variability is important when using aerogel compositions in highly precise manufactured assemblies (e.g., automobile battery packs), where dimensional tolerances are often in the millimeter or submillimeter range, all of which is unexpected for compressed aerogel alone. Thickness values ​​were measured 24 hours after formation.

[0077] To better understand the physical properties of the formed aerogels, the maximum stress at 50% strain was measured for the compressed aerogel as well as the compressed and heated aerogel. The value for the compressed aerogel was 1195.67 kPa, with a 50% strain standard deviation of the maximum stress of 180.8. The value for the compressed and heated aerogel was 1841.33 kPa, with a 50% strain standard deviation of the maximum stress of 426.08. This demonstrated that while both gels can achieve adequate strength, the compressed and heated aerogel in particular can exhibit superior and unpredictable strength.

[0078] The compression setpoints of the compressed aerogel and the compressed and heated aerogel were determined. The compression setpoint for the compressed aerogel was 45.3550% with a compression setpoint standard deviation of 5.72, and the compression setpoint for the compressed and heated aerogel was 50.01383% with a compression setpoint standard deviation of 4.64. This indicates that although the inelastic component of strain between the gels was statistically identical, compression alone does not provide the unexpected benefits mentioned herein.

[0079] The thermal conductivity of the compressed aerogel and the compressed and heated aerogel was determined. The thermal conductivity of the compressed aerogel was shown to be 16.011 mW / mK with a thermal conductivity standard deviation of 0.0341. The thermal conductivity of the compressed and heated aerogel was 16.089 mW / mK with a thermal conductivity standard deviation of 0.377. This indicates that although the thermal conductivities between the gels were statistically identical, compression alone does not provide the unexpected benefits mentioned herein.

[0080] Example 3 Composite aerogels containing octadecyltrimethoxysilane on partially oxidized polyacrylonitrile were fabricated. The initial density of the aerogel was 0.0825 g / cc with an initial thickness of 2 mm. Density refers to grams of silica per unit volume of gel. The target thickness following compression and / or heating was 0.92 mm.

[0081] The aerogel was initially compressed without heating, achieving a thickness of 1.105 mm with a thickness standard deviation of 0.0549 mm. When the aerogel was compressed and heated, the thickness was 1.038 mm with a thickness standard deviation of 0.055 mm. This indicates that compression and heat together produce a reasonable thickness that is less than that possible with compression alone. The improved dimensional control (producing thicker samples) relative to compressed aerogel alone is unexpected. Thickness values ​​were measured 24 hours after formation.

[0082] To better understand the physical properties of the formed aerogels, the maximum stress at 50% strain was measured for the compressed aerogel as well as the compressed and heated aerogel. The value for the compressed aerogel was 8780.8 kPa, with a 50% strain standard deviation of the maximum stress of 1107.10. The value for the compressed and heated aerogel was 10689.8 kPa, with a 50% strain standard deviation of the maximum stress of 1321.21. This demonstrated that while both gels can achieve adequate strength, the compressed and heated aerogel in particular can exhibit superior and unpredictable strength.

[0083] The compression set points of the compressed aerogel and the compressed and heated aerogel were determined. The compression set point of the compressed aerogel was 61.7% with a compression set point standard deviation of 4.32, and the compression set point of the compressed and heated aerogel was 67.5 with a compression set point standard deviation of 1.38. This indicates that although the inelastic components of strain between the gels were statistically close to identical, compression alone does not provide the unexpected benefits mentioned herein. Indeed, it indicates that compression and heating together provide higher compression set points with lower standard deviation values.

[0084] The thermal conductivity of the compressed aerogel and the compressed and heated aerogel was determined. The thermal conductivity of the compressed aerogel was shown to be 19.45 mW / mK with a thermal conductivity standard deviation of 0.56. The thermal conductivity of the compressed and heated aerogel was 19.67 mW / mK with a thermal conductivity standard deviation of 0.90. This indicates that although the thermal conductivities between the gels were statistically identical, compression alone does not provide the unexpected benefits mentioned herein.

[0085] Example 4 Composite aerogels containing octadecyltrimethoxysilane on partially oxidized polyacrylonitrile were fabricated. The initial density of the aerogel was 0.0825 g / cc with an initial thickness of 1 mm. Density refers to grams of silica per unit volume of gel. The target thickness following compression and / or heating was 0.46 mm.

[0086] The aerogel was initially compressed without heating, achieving a thickness of 0.60 mm with a thickness standard deviation of 0.041 mm. When the aerogel was compressed and heated, the thickness was 0.60 mm with a thickness standard deviation of 0.042 mm. This indicates that compression and heating together provide a better standard deviation with adequate thickness with some control in achieving the target thickness, all of which is unexpected relative to compressed aerogel alone. Thickness values ​​were measured 24 hours after formation.

[0087] To better understand the physical properties of the formed aerogels, the maximum stress at 50% strain was measured for the compressed aerogel as well as the compressed and heated aerogel. The value for the compressed aerogel was 20,728.7 kPa, with a 50% strain standard deviation of the maximum stress of 5,204.5. The value for the compressed and heated aerogel was 23,073.5 kPa, with a 50% strain standard deviation of the maximum stress of 9,828.5. This demonstrated that while both gels can achieve adequate strength, the compressed and heated aerogel in particular can exhibit superior and unpredictable strength.

[0088] The compression set points of the compressed aerogel and the compressed and heated aerogel were determined. The compression set point of the compressed aerogel was 56.9% with a compression set point standard deviation of 17.9, and the compression set point of the compressed and heated aerogel was 29.13% with a compression set point standard deviation of 15.58.

[0089] The thermal conductivity of the compressed aerogel and the compressed and heated aerogel was determined. The thermal conductivity of the compressed aerogel was shown to be 15 mW / mK with a thermal conductivity standard deviation of 1.9. The thermal conductivity of the compressed and heated aerogel was 12 mW / mK with a thermal conductivity standard deviation of 2.7. This indicates that although the thermal conductivities between the gels were statistically identical, compression alone does not provide the unexpected benefits mentioned herein.

[0090] Example 5 Composite aerogels containing octadecyltrimethoxysilane on partially oxidized polyacrylonitrile were fabricated. The initial density of the aerogel was 0.0425 g / cc with an initial thickness of 2 mm. Density refers to grams of silica per unit volume of gel. The target thickness following compression and / or heating was 0.92 mm.

[0091] The aerogel was initially compressed without heating, achieving a thickness of 1.31 mm with a thickness standard deviation of 0.095 mm. When the aerogel was compressed and heated, the thickness was 1.07 mm with a thickness standard deviation of 0.056 mm. This shows that compression and heating together provide orders of magnitude better standard deviation with adequate thickness and a degree of control in achieving the target thickness, all of which is unexpected for compressed aerogel alone. Thickness values ​​were measured 24 hours after formation.

[0092] To better understand the physical properties of the formed aerogels, the maximum stress at 50% strain was measured for the compressed aerogel as well as the compressed and heated aerogel. The value for the compressed aerogel was 800.667 kPa, with a maximum stress at 50% strain standard deviation of 288.70. The value for the compressed and heated aerogel was 413.66 kPa, with a maximum stress at 50% strain standard deviation of 72.67. This demonstrated that while both gels can achieve adequate strength, the compressed and heated aerogel in particular can exhibit superior and unpredictable strength. Additionally, the compressed and heated aerogel is a less stressed material. Furthermore, the standard deviation between the compressed and heated and compressed only aerogels is much smaller, indicating a greater degree of control.

[0093] The compression set points for the compressed aerogel and the compressed and heated aerogel were determined. The compression set point for the compressed aerogel was 30.5% with a compression set point standard deviation of 6.048, and the compression set point for the compressed and heated aerogel was 13.2% with a compression set point standard deviation of 2.4. This indicates that both compression and heating provide a desirable lower compression set point with better control, as indicated by the lower standard deviation.

[0094] The thermal conductivity of the compressed aerogel and the compressed and heated aerogel was determined. The thermal conductivity of the compressed aerogel was shown to be 19.24 mW / mK with a thermal conductivity standard deviation of 0.41. The thermal conductivity of the compressed and heated aerogel was 18.54 mW / mK with a thermal conductivity standard deviation of 0.49. This indicates that although the thermal conductivities between the gels were statistically identical, compression alone does not provide the unexpected benefits mentioned herein.

[0095] Example 6 Composite aerogels containing octadecyltrimethoxysilane on partially oxidized polyacrylonitrile were fabricated. The initial density of the aerogel was 0.0425 g / cc with an initial thickness of 2 mm. Density refers to grams of silica per unit volume of gel. The target thickness following compression and / or heating was 0.46 mm.

[0096] The aerogels were initially compressed without heating, achieving a thickness of 0.85 mm with a thickness standard deviation of 0.011 mm. When the aerogels were compressed and heated, the thickness was 0.62 mm with a thickness standard deviation of 0.08 mm. This indicates that compression and heating together provide adequate thickness with a degree of control in achieving the target thickness that is unexpected for compressed aerogels alone. Thickness values ​​were measured 24 hours after formation.

[0097] The thermal conductivity of the compressed aerogel and the compressed and heated aerogel was determined. The thermal conductivity of the compressed aerogel was shown to be 22.5 mW / mK with a thermal conductivity standard deviation of 0.227. The thermal conductivity of the compressed and heated aerogel was 23.1 mW / mK with a thermal conductivity standard deviation of 0.171. This indicates that although the thermal conductivities between the gels were statistically identical, compression alone does not provide the unexpected benefits mentioned herein.

[0098] In the preceding examples, thermal conductivity is measured using ASTM C518. In the preceding examples, stress, strain, and compression were determined using ASTM E3574. Statistical analysis was performed using a computer program called JMP 17, available from JMP Statistical Discovery LLC, Cary, NC.

[0099] The terms and expressions employed are used as terms of description, and there is no intention to use such terms and expressions to exclude any equivalents or portions thereof of the features shown and described, but it will be recognized that various modifications are possible within the scope of the aspects of the present disclosure. Thus, while the present disclosure has been specifically disclosed in terms of certain aspects, it should be understood that optional features, modifications, and variations of the concepts disclosed herein may be reclassified by those skilled in the art, and that such modifications and variations are within the scope of the aspects of the present disclosure.

[0100] Exemplary Embodiments The following exemplary aspects are provided, the numbering of which is not to be construed as a designated level of importance.

[0101] Aspect 1 provides a method of making an aerogel composite, the method comprising: compressing and heating the aerogel composite, the aerogel composite including a gel dispersed around a reinforcing component; producing a compressed and heated aerogel composite, the aerogel composite comprising a plurality of pores, a majority of which have a diameter of less than 50 nm; Includes.

[0102] Example 2 provides the method of Example 1, wherein the gel comprises a metal oxide compound.

[0103] Example 3 provides the method of example 2, wherein the metal oxide compound comprises silica, alumina, titania, ceria, yttria, or any combination thereof.

[0104] Example 4 provides the method of any one of Examples 2 or 3, wherein the metal oxide compound comprises silica.

[0105] Example 5 provides the method of any one of Examples 1-4, wherein the reinforcement component comprises a non-woven material, a woven material, a loft batting, a fiber batting, or any combination thereof.

[0106] Example 6 provides the method of any one of Examples 1-5, wherein the reinforcing component comprises inorganic fibers, organic fibers, particles, metal fibers, metal mesh, organic foam, or a mixture thereof.

[0107] Example 7 provides the method of example 6, wherein the inorganic fibers comprise glass fibers or ceramic fibers.

[0108] Example 8 provides the method of any one of Examples 6 or 7, wherein the organic fibers comprise polyethylene, oxidized polyacrylonitrile, polyacrylonitrile, polyethylene terephthalate, or a mixture thereof.

[0109] Example 9 provides the method of example 8, wherein the reinforcing component comprises a composite polyethylene terephthalate fiber comprising an inner core and an outer core, the inner core having a melting temperature greater than the melting temperature of the outer core.

[0110] Example 10 provides the method of any one of Examples 6-9, wherein the organic foam comprises melamine.

[0111] Example 11 provides the method of any one of Examples 1-10, wherein the reinforcing component is in the range of about 5 wt% to about 75 wt% of the aerogel composite.

[0112] Example 12 provides the method of any one of Examples 1-11, wherein the reinforcing component is in the range of about 25 wt% to about 50 wt% of the aerogel composite.

[0113] Example 13 provides the method of any one of Examples 1-12, wherein the density of the aerogel composite is increased by up to 20 times relative to the gel before compaction.

[0114] Example 14 provides the method of any one of Examples 1-13, wherein the density of the aerogel composite is increased by up to 10 times relative to the gel before compaction.

[0115] Example 15 provides the method of any one of Examples 1-14, wherein the compressing and heating are performed simultaneously.

[0116] Example 16 provides the method of any one of Examples 1-14, wherein the heating is performed after compressing.

[0117] Example 17 provides the method of any one of Examples 1-16, wherein the compressing comprises mechanical compressing or pneumatic compressing.

[0118] Example 18 provides the method of Example 17, wherein the mechanical compressing is accomplished by a compression device.

[0119] Example 19 provides the method of Example 18, wherein the compression device comprises a press, a roller, or both.

[0120] Example 20 provides the method of any one of Examples 18 or 19, wherein the compression device is heated.

[0121] Example 21 provides the method of any one of Examples 1-20, wherein the gel dispersed around the reinforcing component is heated to a temperature ranging from about 80°C to about 700°C.

[0122] Example 22 provides the method of any one of Examples 1-21, wherein the gel dispersed around the reinforcing component is heated to a temperature ranging from about 90°C to about 110°C.

[0123] Example 23 provides the method of any one of Examples 1-22, wherein the heating is carried out at a constant temperature.

[0124] Example 24 provides the method of any one of Examples 1-23, wherein the heating is performed across a temperature gradient.

[0125] Example 25 provides the method of any one of Examples 1-24, wherein the heating is performed over multiple heating cycles.

[0126] Example 26 provides the method of any one of Examples 1-25, wherein compressing the gel dispersed around the reinforcement component is accomplished at a pressure of up to about 1000 kPa.

[0127] Example 27 provides the method of any one of Examples 1-26, wherein compressing the gel dispersed around the reinforcement component is accomplished at a pressure ranging from about 500 kPa to about 1000 kPa.

[0128] Example 28 provides the method of any one of Examples 1-27, wherein compressing the gel dispersed around the reinforcement component is accomplished at a pressure ranging from about 700 kPa to about 1000 kPa.

[0129] Example 29 provides the method of any one of Examples 1-28, wherein the compressing is carried out for a period ranging from about 0.2 hours to about 24 hours.

[0130] Example 30 provides the method of any one of Examples 1-29, further comprising distributing an additive throughout the gel.

[0131] Example 31 provides the method of Example 30, wherein the additive is in the range of about 0.05 wt % to about 10 wt % of the aerogel composite.

[0132] Example 32 provides the method of any one of Examples 30 or 31, wherein the additive is in the range of about 1 wt % to about 7 wt % of the aerogel composite.

[0133] Example 33 provides the method of any one of Examples 30-32, wherein the additive comprises boron carbide [BC], diatomaceous earth, manganese ferrite, MnO, NiO, SnO, AgO, BiO, carbon black, titanium oxide, iron titanium oxide, aluminum oxide, zirconium silicate, zirconium oxide, iron (II) oxide, iron (III) oxide, manganese dioxide, titanium iron oxide (ilmenite), chromium oxide, SiC, TiC, or WC, TiOSO, TiOCl, or a mixture thereof.

[0134] Example 34 provides the method of any one of Examples 1-33, further comprising contacting the prepared aerogel composite with a solution comprising ethanol and hexamethyldisiloxane.

[0135]

[0023] Example 35 provides the method of any one of Examples 1 to 34, wherein the compressed aerogel composite has a thickness of 1 mm to 1.62 mm, and the thickness standard deviation is 0.042 mm to 0.056 mm, and in some embodiments, 1.62 mm with a thickness standard deviation of 0.05 mm, 1.038 mm with a thickness standard deviation of 0.055 mm, 0.60 mm with a thickness standard deviation of 0.042 mm, 1.07 mm with a thickness standard deviation of 0.056 mm, or 0.62 mm with a thickness standard deviation of 0.08 mm, Includes.

[0136]

[0023] Example 36 provides the method of any one of Examples 1-35, wherein the compressed aerogel composite has strain values ​​at 50% of maximum stress of 413.66 kPa to 23073.5 kPa, and the maximum stress at 50% strain standard deviation is from 72.67 kPa to 9828.5 kPa; and in some embodiments, 1841.33 kPa, with a maximum stress at 50% strain standard deviation of 426.08 10689.8 kPa, with a maximum stress at 50% strain standard deviation of 1321.21 23073.5 kPa with a maximum stress at 50% strain standard deviation of 9828.5, or 413.66 kPa, with a maximum stress at 50% strain standard deviation of 72.67 Includes.

[0137]

[0023] Example 37 provides the method of any one of Examples 1-36, wherein the compressed aerogel composite having a compression set point of 13% to 68% has a compression set point standard deviation of 1.38% to 15.58%, and in some embodiments, 50.01383%, with a compression setting standard deviation of 4.64 67.5% with a compression setting standard deviation of 1.38, 29.13 with a compression setpoint standard deviation of 15.58, or 13.2% with a compression setting standard deviation of 2.4, may include:

[0138]

[0023] Example 38 provides the method of any one of Examples 1 to 37, wherein the compressed aerogel composite has a thermal conductivity of 16 mW / mK to 23.1 mW / mK, and the thermal conductivity standard deviation is 0.0377 mW / mK to 2.7 mW / mK, and in some embodiments, 16.089 mW / mK with a thermal conductivity standard deviation of 0.0377, 19.67 mW / mk, with a thermal conductivity standard deviation of 0.90 12mWmK with a thermal conductivity standard deviation of 2.7, 18.54 mW / mK with a thermal conductivity standard deviation of 0.49, or 23.1 mW / mK with a thermal conductivity standard deviation of 0.171, may include:

[0139] Example 39 provides the method of any one of Examples 1-38, wherein the thickness of the prepared aerogel composite ranges from about 0.1 mm to about 0.6 mm.

[0140] Example 40 provides the method of any one of Examples 1-39, wherein the thickness of the prepared aerogel composite ranges from about 0.1 mm to about 0.5 mm.

[0141] Example 41 provides a method of making an aerogel composite, the method comprising: compressing and heating the aerogel composite, the aerogel composite comprising silica gel dispersed around a reinforcing component comprising polyethylene, polyacrylonitrile oxide, polyacrylonitrile, polyethylene terephthalate, or a mixture thereof, and the heating is performed at a temperature above the glass transition temperature of the polyethylene, polyacrylonitrile oxide, polyacrylonitrile, polyethylene terephthalate, or a mixture thereof; producing a compressed and heated aerogel composite, the aerogel composite comprising a plurality of pores, the majority of which have a diameter of less than 50 nm; Includes.

[0142] Example 42 provides the method of example 41, wherein the reinforcing component comprises a composite polyethylene terephthalate fiber comprising an inner core and an outer core, the inner core having a melting temperature greater than the melting temperature of the outer core.

[0143] Example 43 provides the method of any one of Examples 41 or 42, wherein the reinforcing component is in the range of about 5 wt% to about 75 wt% of the aerogel composite.

[0144] Example 44 provides the method of any one of Examples 41-43, wherein the density of the aerogel composite is increased by up to 20 times relative to the gel before compaction.

[0145] Example 45 provides the method of any one of Examples 41-44, wherein the density of the aerogel composite is increased by up to 10 times relative to the gel before compaction.

[0146] Example 46 provides the method of any one of Examples 41-45, wherein the compressing comprises mechanical compressing or pneumatic compressing.

[0147] Example 47 provides the method of Example 46, wherein the mechanical compressing is accomplished by a compression device.

[0148] Example 48 provides the method of example 47, wherein the compression device includes a press, a roller, or both.

[0149] Example 49 provides the method of any one of Examples 47 or 48, wherein the compression device is heated.

[0150] Example 50 provides the method of any one of Examples 41-49, wherein the heating is performed at a constant temperature.

[0151] Example 51 provides the method of any one of Examples 41-50, wherein the heating is performed across a temperature gradient.

[0152] Example 52 provides the method of any one of Examples 41-51, wherein the heating is performed over multiple heating cycles.

[0153] Example 53 provides the method of any one of Examples 41-52, wherein compressing the gel dispersed around the reinforcement component is accomplished at a pressure of up to about 1000 kPa.

[0154] Example 54 provides the method of any one of Examples 41-53, wherein compressing the gel dispersed around the reinforcement component is accomplished at a pressure ranging from about 500 kPa to about 1000 kPa.

[0155] Example 55 provides the method of any one of Examples 41-54, wherein compressing the gel dispersed around the reinforcement component is accomplished at a pressure ranging from about 700 kPa to about 1000 kPa.

[0156] Example 56 provides the method of any one of Examples 41-55, wherein the compressing is carried out for a period ranging from about 0.2 hours to about 24 hours.

[0157] Example 57 provides the method of any one of Examples 41-56, further comprising distributing an additive around the gel.

[0158] Example 58 provides the method of example 57, wherein the additive is in the range of about 0.05 wt % to about 10 wt % of the aerogel composite.

[0159] Example 59 provides the method of any one of Examples 57 or 58, wherein the additive is in the range of about 1 wt % to about 7 wt % of the aerogel composite.

[0160] Example 60 provides the method of any one of Examples 57-59, wherein the additive comprises boron carbide [BC], diatomaceous earth, manganese ferrite, MnO, NiO, SnO, AgO, BiO, carbon black, titanium oxide, iron titanium oxide, aluminum oxide, zirconium silicate, zirconium oxide, iron (II) oxide, iron (III) oxide, manganese dioxide, titanium iron oxide (ilmenite), chromium oxide, SiC, TiC, or WC, TiOSO, TiOCl, or a mixture thereof.

[0161] Example 61 provides the method of any one of Examples 41-60, comprising contacting the prepared aerogel composite with a solution comprising ethanol and bis(trimethylsilyl)amine.

[0162]

[0023] Example 62 provides the method of any one of Examples 41 to 61, wherein the compressed aerogel composite has a thickness of 1 mm to 1.62 mm, and the thickness standard deviation is 0.042 mm to 0.056 mm, and in some embodiments, 1.62 mm with a thickness standard deviation of 0.05 mm, 1.038 mm with a thickness standard deviation of 0.055 mm, 0.60 mm with a thickness standard deviation of 0.042 mm, 1.07 mm with a thickness standard deviation of 0.056 mm, or 0.62 mm with a thickness standard deviation of 0.08 mm, Includes.

[0163]

[0023] Example 63 provides the method of any one of Examples 41-62, wherein the compressed aerogel composite has strain values ​​at 50% of maximum stress between 413.66 kPa and 23073.5 kPa, and the maximum stress at 50% strain standard deviation is between 72.67 kPa and 9828.5 kPa; and in some embodiments, 1841.33 kPa, with a maximum stress at 50% strain standard deviation of 426.08 10689.8 kPa, with a maximum stress at 50% strain standard deviation of 1321.21 23073.5 kPa with a maximum stress at 50% strain standard deviation of 9828.5, or 413.66 kPa, with a maximum stress at 50% strain standard deviation of 72.67 Includes.

[0164] Example 64 provides the method of any one of Examples 41 to 63, wherein the compressed aerogel composite having a compression set point of 13% to 68% has a compression set point standard deviation of 1.38% to 15.58%, and in some embodiments, 50.01383%, with a compression setting standard deviation of 4.64 67.5% with a compression setting standard deviation of 1.38, 29.13 with a compression setpoint standard deviation of 15.58, or 13.2% with a compression setting standard deviation of 2.4, may include:

[0165]

[0023] Example 65 provides the method of any one of Examples 41 to 64, wherein the compressed aerogel composite has a thermal conductivity of 16 mW / mK to 23.1 mW / mK, and the thermal conductivity standard deviation is 0.0377 mW / mK to 2.7 mW / mK, and in some embodiments, 16.089 mW / mK with a thermal conductivity standard deviation of 0.0377, 19.67 mW / mk, with a thermal conductivity standard deviation of 0.90 12mWmK with a thermal conductivity standard deviation of 2.7, 18.54 mW / mK with a thermal conductivity standard deviation of 0.49, or 23.1 mW / mK with a thermal conductivity standard deviation of 0.171, may include:

[0166] Example 66 provides the method of any one of Examples 41-65, wherein the thickness of the prepared aerogel composite ranges from about 0.1 mm to about 0.6 mm.

[0167] Example 67 provides the method of any one of Examples 41-66, wherein the thickness of the prepared aerogel composite ranges from about 0.1 mm to about 0.5 mm.

[0168] Example 68 provides a compressed aerogel composite, comprising: a gel including a metal oxide compound dispersed around a reinforcing component; The aerogel composite comprises a plurality of pores, the majority of which have a diameter less than 50 nm.

[0169] Example 69 provides the compressed aerogel composite of Example 68, wherein the compressed aerogel composite has a thickness of 1 mm to 1.62 mm, and the thickness standard deviation is 0.042 mm to 0.056 mm, and in some embodiments, 1.62 mm with a thickness standard deviation of 0.05 mm, 1.038 mm with a thickness standard deviation of 0.055 mm, 0.60 mm with a thickness standard deviation of 0.042 mm, 1.07 mm with a thickness standard deviation of 0.056 mm, or 0.62 mm with a thickness standard deviation of 0.08 mm, Includes.

[0170] Example 70 provides the compressed aerogel composite of any of Examples 68 or 69, wherein the compressed aerogel composite has strain values ​​at 50% of maximum stress between 413.66 kPa and 23073.5 kPa, and the maximum stress at 50% strain standard deviation is between 72.67 kPa and 9828.5 kPa, and in some embodiments, 1841.33 kPa, with a maximum stress at 50% strain standard deviation of 426.08 10689.8 kPa, with a maximum stress at 50% strain standard deviation of 1321.21 23073.5 kPa with a maximum stress at 50% strain standard deviation of 9828.5, or 413.66 kPa, with a maximum stress at 50% strain standard deviation of 72.67 Includes.

[0171] Example 71 provides the compressed aerogel composite of any of Examples 68-70, wherein the compressed aerogel composite having a compression set point between 13% and 68% has a compression set point standard deviation between 1.38% and 15.58%, and in some embodiments, 50.01383%, with a compression setting standard deviation of 4.64 67.5% with a compression setting standard deviation of 1.38, 29.13 with a compression setpoint standard deviation of 15.58, or 13.2% with a compression setting standard deviation of 2.4, may include:

[0172]

[0039] Example 72 provides the compressed aerogel composite of any of Examples 68 to 71, wherein the compressed aerogel composite has a thermal conductivity of 16 mW / mK to 23.1 mW / mK, and the thermal conductivity standard deviation is 0.0377 mW / mK to 2.7 mW / mK, and in some embodiments, 16.089 mW / mK with a thermal conductivity standard deviation of 0.0377, 19.67 mW / mk, with a thermal conductivity standard deviation of 0.90 12mWmK with a thermal conductivity standard deviation of 2.7, 18.54 mW / mK with a thermal conductivity standard deviation of 0.49, or 23.1 mW / mK with a thermal conductivity standard deviation of 0.171, may include:

Claims

1. 1. A method of making an aerogel composite, comprising: compressing and heating the aerogel composite, the aerogel composite including a gel dispersed around a reinforcing component; producing a compressed and heated aerogel composite, the aerogel composite comprising a plurality of pores, a majority of which have a diameter of less than 50 nm; The method comprising:

2. The method of claim 1 , wherein the gel comprises a metal oxide compound.

3. The method of claim 2 , wherein the metal oxide compound comprises silica, alumina, titania, ceria, yttria, or any combination thereof.

4. 4. The method of claim 2, wherein the metal oxide compound comprises silica.

5. The method of any one of claims 1 to 4, wherein the reinforcing component comprises a non-woven material, a woven material, a loft batting, a fiber batting, or any combination thereof.

6. The method of any one of claims 1 to 5, wherein the reinforcing component comprises inorganic fibers, organic fibers, particles, metal fibers, metal mesh, organic foam, or mixtures thereof.

7. The method of claim 6 , wherein the inorganic fibers comprise glass fibers or ceramic fibers.

8. 8. The method of claim 6 or 7, wherein the organic fibers comprise polyethylene, oxidized polyacrylonitrile, polyacrylonitrile, polyethylene terephthalate, or mixtures thereof.

9. The method of claim 8 , wherein the reinforcing component comprises a composite polyethylene terephthalate fiber comprising an inner core and an outer core, the inner core having a melting temperature greater than the melting temperature of the outer core.

10. The method of any one of claims 6 to 9, wherein the organic foam comprises melamine.

11. 11. The method of any one of claims 1 to 10, wherein the reinforcing component is in the range of about 5 wt% to about 75 wt% of the aerogel composite.

12. 12. The method of any one of claims 1 to 11, wherein the reinforcing component is in the range of about 25 wt% to about 50 wt% of the aerogel composite.

13. 13. The method of any one of claims 1 to 12, wherein the density of the aerogel composite is increased by up to 20 times relative to the gel before compaction.

14. 14. The method of any one of claims 1 to 13, wherein the density of the aerogel composite is increased by up to 10 times relative to the gel before compaction.

15. The method of any one of claims 1 to 14, wherein the compressing and heating are carried out simultaneously.

16. The method of any one of claims 1 to 14, wherein the heating is carried out after compacting.

17. The method of any one of claims 1 to 16, wherein the compressing comprises mechanical compressing or pneumatic compressing.

18. 20. The method of claim 17, wherein said mechanical compressing is accomplished by a compression device.

19. The method of claim 18 , wherein the compression device comprises a press, a roller, or both.

20. 20. The method of claim 18 or 19, wherein the compression device is heated.

21. The method of any one of claims 1 to 20, wherein the gel dispersed around the reinforcing component is heated to a temperature in the range of about 80°C to about 700°C.

22. The method of any one of claims 1 to 21, wherein the gel dispersed around the reinforcing component is heated to a temperature in the range of about 90°C to about 110°C.

23. The method of any one of claims 1 to 22, wherein the heating is carried out at a constant temperature.

24. A method according to any preceding claim, wherein the heating is carried out over a temperature gradient.

25. The method of any one of claims 1 to 24, wherein the heating is carried out over multiple heating cycles.

26. 26. The method of any one of claims 1 to 25, wherein compressing the gel dispersed around the reinforcing component is accomplished at a pressure of up to about 1000 kPa.

27. 27. The method of any one of claims 1 to 26, wherein compressing the gel dispersed around the reinforcement component is accomplished at a pressure ranging from about 500 kPa to about 1000 kPa.

28. 28. The method of any one of claims 1 to 27, wherein compressing the gel dispersed around the reinforcement component is accomplished at a pressure ranging from about 700 kPa to about 1000 kPa.

29. 29. The method of any one of claims 1 to 28, wherein the compacting is carried out for a period ranging from about 0.2 hours to about 24 hours.

30. 30. The method of any one of claims 1 to 29, further comprising distributing an additive throughout the gel.

31. 31. The method of claim 30, wherein the additive is in the range of about 0.05 wt % to about 10 wt % of the aerogel composite.

32. 32. The method of claim 30, wherein the additive is in the range of about 1 wt % to about 7 wt % of the aerogel composite.

33. The additive is boron carbide [B ４ C], diatomaceous earth, manganese ferrite, MnO, NiO, SnO, Ag ２ O, Bi ２ O ３ , carbon black, titanium oxide, iron titanium oxide, aluminum oxide, zirconium silicate, zirconium oxide, iron (II) oxide, iron (III) oxide, manganese dioxide, titanium iron oxide (ilmenite), chromium oxide, SiC, TiC or WC, TIOSO ４ , TiOCl ２ 33. The method of any one of claims 30 to 32, comprising:

34. 34. The method of any one of claims 1 to 33, further comprising contacting the prepared aerogel composite with a solution comprising ethanol and hexamethyldisiloxane.

35. 35. The method of any one of claims 1 to 34, wherein the compressed aerogel composite having a thickness of 1 mm to 1.62 mm has a thickness standard deviation of 0.42 mm to 0.55 mm.

36. 36. The method of any one of claims 1 to 35, wherein the compressed aerogel composite has a maximum stress at 50% strain of 413.66 kPa to 23073.5 kPa.

37. 37. The method of any one of claims 1 to 36, wherein the compressed aerogel composite has a compression set point of 13% to 68%.

38. 38. The method of any one of claims 1 to 37, wherein the thermal conductivity of the compressed aerogel composite is between 16 mW / mK and 23.1 mW / mK.

39. 39. The method of any one of claims 1 to 38, wherein the thickness of the produced aerogel composite ranges from about 0.1 mm to about 0.6 mm.

40. 40. The method of any one of claims 1 to 39, wherein the thickness of the produced aerogel composite ranges from about 0.1 mm to about 0.5 mm.

41. 1. A method of making an aerogel composite, comprising: compressing and heating the aerogel composite, the aerogel composite including silica gel dispersed around a reinforcing component including polyethylene, polyacrylonitrile, polyacrylonitrile oxide, polyethylene terephthalate, or a mixture thereof, and the heating is performed at a temperature above the glass transition temperature of the polyethylene, polyacrylonitrile, polyacrylonitrile oxide, polyethylene terephthalate, or a mixture thereof; producing a compressed and heated aerogel composite, the aerogel composite comprising a plurality of pores, the majority of which have a diameter of less than 50 nm; The method comprising:

42. 42. The method of claim 41, wherein the reinforcing component comprises a composite polyethylene terephthalate fiber comprising an inner core and an outer core, the inner core having a melting temperature greater than the melting temperature of the outer core.

43. 43. The method of claim 41 or 42, wherein the reinforcing component is in the range of about 5 wt % to about 75 wt % of the aerogel composite.

44. 44. The method of any one of claims 41 to 43, wherein the density of the aerogel composite is increased by up to 20 times relative to the gel before compaction.

45. 45. The method of any one of claims 41 to 44, wherein the density of the aerogel composite is increased by up to 10 times relative to the gel before compaction.

46. The method of any one of claims 41 to 45, wherein the compressing comprises mechanical compressing or pneumatic compressing.

47. 47. The method of claim 46, wherein said mechanical compressing is accomplished by a compression device.

48. 48. The method of claim 47, wherein the compression device comprises a press, a roller, or both.

49. 49. The method of any one of claims 47 or 48, wherein the compression device is heated.

50. 50. The method of any one of claims 41 to 49, wherein the heating is carried out at a constant temperature.

51. 51. The method of any one of claims 41 to 50, wherein the heating is carried out over a temperature gradient.

52. 52. The method of any one of claims 41 to 51, wherein the heating is carried out over multiple heating cycles.

53. 53. The method of any one of claims 41 to 52, wherein compressing the gel dispersed around the reinforcing component is achieved at a pressure of up to about 1000 kPa.

54. 54. The method of any one of claims 41 to 53, wherein compressing the gel dispersed around the reinforcement component is accomplished at a pressure in the range of about 500 kPa to about 1000 kPa.

55. 55. The method of any one of claims 41 to 54, wherein compressing the gel dispersed around a reinforcement component is accomplished at a pressure in the range of about 700 kPa to about 1000 kPa.

56. 56. The method of any one of claims 41 to 55, wherein the compressing is carried out for a period ranging from about 0.2 hours to about 24 hours.

57. 57. The method of any one of claims 41 to 56, further comprising distributing an additive around the gel.

58. 58. The method of claim 57, wherein the additive is in the range of about 0.05 wt % to about 10 wt % of the aerogel composite.

59. 59. The method of claim 57 or 58, wherein the additive is in the range of about 1 wt % to about 7 wt % of the aerogel composite.

60. The additive is boron carbide [B ４ C], diatomaceous earth, manganese ferrite, MnO, NiO, SnO, Ag ２ O, Bi ２ O ３ , carbon black, titanium oxide, iron titanium oxide, aluminum oxide, zirconium silicate, zirconium oxide, iron (II) oxide, iron (III) oxide, manganese dioxide, titanium iron oxide (ilmenite), chromium oxide, SiC, TiC or WC, TIOSO ４ , TiOCl ２ 60. The method of any one of claims 57 to 59, comprising:

61. 61. The method of any one of claims 41-60, comprising contacting the fabricated aerogel composite with a solution comprising ethanol and bis(trimethylsilyl)amine.

62. 62. The method of any one of claims 41 to 61, wherein the compressed aerogel composite having a thickness of 1 mm to 1.62 mm has a thickness standard deviation of 0.42 mm to 0.55 mm.

63. 63. The method of any one of claims 41 to 62, wherein the compressed aerogel composite has a maximum stress at 50% strain of 413.66 kPa to 23073.5 kPa.

64. 64. The method of any one of claims 41 to 63, wherein the compressed aerogel composite has a compression set point of 13% to 68%.

65. 65. The method of any one of claims 41 to 64, wherein the thermal conductivity of the compressed aerogel composite is between 16 mW / mK and 23.1 mW / mK.

66. 66. The method of any one of claims 41 to 65, wherein the thickness of the fabricated aerogel composite ranges from about 0.1 mm to about 0.6 mm.

67. 67. The method of any one of claims 41 to 66, wherein the thickness of the fabricated aerogel composite ranges from about 0.1 mm to about 0.5 mm.

68. 1. A compressed aerogel composite material comprising: a gel including a metal oxide compound dispersed around a reinforcing component; the aerogel composite comprises a plurality of pores, the majority of which have a diameter of less than 50 nm; The compressed aerogel composite.

69. 69. The compressed aerogel composite of claim 68, wherein the compressed aerogel composite having a thickness between 1 mm and 1.62 mm has a thickness standard deviation between 0.42 mm and 0.55 mm.

70. 70. The compressed aerogel composite of claim 68 or 69, wherein the compressed aerogel composite has a maximum stress at 50% strain of 413.66 kPa to 23073.5 kPa.

71. 71. The compressed aerogel composite of any one of claims 68 to 70, wherein the compressed aerogel composite has a compression set point of 13% to 68%.

72. 72. The compressed aerogel composite of any one of claims 68 to 71, wherein the thermal conductivity of the compressed aerogel composite is from 16 mW / mK to 23.1 mW / mK.

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