Abstract: The present invention discloses novel porous polymeric compositions comprising random copolymers of amides, imides, ureas, and carbamic-anhydrides, useful for the synthesis of monolithic bimodal microporous/macroporous carbon aerogels. It also discloses methods for producing said microporous/macroporous carbon aerogels by the reaction of a polyisocyanate compound and a polycarboxylic acid compound, followed by pyrolytic carbonization, and by reactive etching with CO2 at elevated temperatures. Also disclosed are methods for using the microporous/macroporous carbon aerogels in the selective capture and sequestration of carbon dioxide.

Abstract: The present disclosure is directed to methods of forming polyamic acid and polyimide gels in water. The resulting polyamic acid and polyimide gels may be converted to aerogels, which may further be converted to carbon aerogels. Such carbon aerogels have the same physical properties as carbon aerogels prepared from polyimide aerogels obtained according to conventional methods, i.e., organic solvent-based. The disclosed methods are advantageous in reducing or avoiding costs associated with use and disposal of potentially toxic solvents and byproducts. Gel materials prepared according to the disclosed methods are suitable for use in environments involving electrochemical reactions, for example as an electrode material within a lithium-ion battery.

Abstract: Heating and processing a polymeric material is achieved using a microwave absorbing structure that defines a processing chamber to receive the polymeric material (e.g., one or more precursors to form a polymer). A microwave radiation source directs microwave radiation to the microwave absorbing structure, which absorbs the radiation and can process the material.

Abstract: Three-dimensional nanoporous aerogels and suitable preparation methods are provided. Nanoporous aerogels may include a carbide material such as a silicon carbide, a metal carbide, or a metalloid carbide. Elemental (e.g., metallic or metalloid) aerogels may also be produced. In some embodiments, a cross-linked aerogel having a conformal coating on a sol-gel material is processed to form a carbide aerogel, metal aerogel, or metalloid aerogel. A three-dimensional nanoporous network may include a free radical initiator that reacts with a cross-linking agent to form the cross-linked aerogel. The cross-linked aerogel may be chemically aromatized and chemically carbonized to form a carbon-coated aerogel. The carbon-coated aerogel may be suitably processed to undergo a carbothermal reduction, yielding an aerogel where oxygen is chemically extracted. Residual carbon remaining on the surface of the aerogel may be removed via an appropriate cleaning treatment.

Abstract: The present disclosure is directed to methods of forming polyamic acid and polyimide gels in water. The resulting polyamic acid and polyimide gels may be converted to aerogels, which may further be converted to carbon aerogels. Such carbon aerogels have the same physical properties as carbon aerogels prepared from polyimide aerogels obtained according to conventional methods, i.e., organic solvent-based. The disclosed methods are advantageous in reducing or avoiding costs associated with use and disposal of potentially toxic solvents and byproducts. Gel materials prepared according to the disclosed methods are suitable for use in environments involving electrochemical reactions, for example as an electrode material within a lithium-ion battery.

Abstract: The present disclosure is directed to methods of forming polyimide gels. The methods generally include forming a polyamic acid and dehydrating the polyamic acid with a dehydrating agent in the presence of water. The resulting polyimide gels may be converted to polyimide or carbon xerogels or aerogels. The methods are advantageous in providing rapid or even instantaneous gelation, which may be particularly useful in formation of beads comprising the polyimide gels. Polyimide or carbon gel materials prepared according to the disclosed method are suitable for use in environments containing electrochemical reactions, for example as an electrode material within a lithium-ion battery.

Abstract: Porous three-dimensional networks of polyimide and porous three-dimensional networks of carbon and methods of their manufacture are described. For example, polyimide aerogels are prepared by mixing a dianhydride and a diisocyanate in a solvent comprising a pyrrolidone and acetonitrile at room temperature to form a sol-gel material and supercritically drying the sol-gel material to form the polyimide aerogel. Porous three-dimensional polyimide networks, such as polyimide aerogels, may also exhibit a fibrous morphology. Having a porous three-dimensional polyimide network undergo an additional step of pyrolysis may result in the three dimensional network being converted to a purely carbon skeleton, yielding a porous three-dimensional carbon network. The carbon network, having been derived from a fibrous polyimide network, may also exhibit a fibrous morphology.

Abstract: Nanoporous carbon-based scaffolds or structures, and specifically carbon aerogels and their manufacture and use thereof are provided. Embodiments include a silicon-doped anode material for a lithium-ion battery, where the anode material includes beads of a polyimide-derived carbon aerogel. The carbon aerogel may further include silicon particles and accommodates expansion of the silicon particles during lithiation. The anode material provides optimal properties for use within the lithium-ion battery.

Abstract: Novel methods of synthesizing amorphous carbon and graphitic carbon aerogels are provided. The carbon aerogels produced by these methods are highly porous, monolithic carbon aerogels and are extremely robust. Specifically, the amorphous carbon aerogels have high surface areas and large micropore volumes. Due to these extraordinary properties, these aerogels possess high carbon dioxide (CO2) sorption capacities and are highly selective towards CO2 versus other gases, such as H2 and N2. As a result, the amorphous carbon aerogels can be used to effectively capture or remove CO2 from the air and/or from flue gases. Furthermore, the graphitic carbon aerogels notably have high graphite content, crystallite size, and graphite quality, of which are comparable to those of commercial graphite.

Abstract: Porous three-dimensional networks of polyurea and porous three-dimensional networks of carbon and methods of their manufacture are described. In an example, polyurea aerogels are prepared by mixing an triisocyanate with water and a triethylamine to form a sol-gel material and supercritically drying the sol-gel material to form the polyurea aerogel. Subjecting the polyurea aerogel to a step of pyrolysis may result in a three dimensional network having a carbon skeleton, yielding a carbon aerogel. The density and morphology of polyurea aerogels can be controlled by varying the amount of isocyanate monomer in the initial reaction mixture. A lower density in the aerogel gives rise to a fibrous morphology, whereas a greater density in the aerogel results in a particulate morphology. Polyurea aerogels described herein may also exhibit a reduced flammability.

Abstract: The present disclosure is directed to methods of forming polyimide gels. The methods generally include forming a polyamic acid and dehydrating the polyamic acid with a dehydrating agent in the presence of water. The resulting polyimide gels may be converted to polyimide or carbon xerogels or aerogels. The methods are advantageous in providing rapid or even instantaneous gelation, which may be particularly useful in formation of beads comprising the polyimide gels. Polyimide or carbon gel materials prepared according to the disclosed method are suitable for use in environments containing electrochemical reactions, for example as an electrode material within a lithium-ion battery.

Abstract: Nanoporous carbon-based scaffolds or structures, and specifically carbon aerogels and their manufacture and use thereof are provided. Embodiments include a silicon-doped anode material for a lithium-ion battery, where the anode material includes beads of polyimide-derived carbon aerogel. The carbon aerogel includes silicon particles and accommodates expansion of the silicon particles during lithiation. The anode material provides optimal properties for use within the lithium-ion battery.

Abstract: Nanoporous carbon-based scaffolds or structures, and specifically carbon aerogels and their manufacture and use thereof are provided. Embodiments include a silicon-doped anode material for a lithium-ion battery, where the anode material includes beads of polyimide-derived carbon aerogel. The carbon aerogel includes silicon particles and accommodates expansion of the silicon particles during lithiation. The anode material provides optimal properties for use within the lithium-ion battery.

Abstract: Porous three-dimensional networks of polyurea and porous three-dimensional networks of carbon and methods of their manufacture are described. In an example, polyurea aerogels are prepared by mixing an triisocyanate with water and a triethylamine to form a sol-gel material and supercritically drying the sol-gel material to form the polyurea aerogel. Subjecting the polyurea aerogel to a step of pyrolysis may result in a three dimensional network having a carbon skeleton, yielding a carbon aerogel. The density and morphology of polyurea aerogels can be controlled by varying the amount of isocyanate monomer in the initial reaction mixture. A lower density in the aerogel gives rise to a fibrous morphology, whereas a greater density in the aerogel results in a particulate morphology. Polyurea aerogels described herein may also exhibit a reduced flammability.

Abstract: The present disclosure is directed to silica-carbon composite materials including a low bulk density carbon material having a skeletal framework of carbon nanofibers, the skeletal framework forming a pore structure comprising an array of interconnected pores. The silica-carbon composite materials further include a conformal coating layer of silica on the carbon nanofibers. Further provided are methods for preparation of the silica-carbon composite materials, and methods for reduction of the silica-carbon composite materials to provide silicon-carbon composite materials.

Abstract: The present disclosure is directed to methods of forming polyamic acid and polyimide gels in water. The resulting polyamic acid and polyimide gels may be converted to aerogels, which may further be converted to carbon aerogels. Such carbon aerogels have the same physical properties as carbon aerogels prepared from polyimide aerogels obtained according to conventional methods, i.e., organic solvent-based. The disclosed methods are advantageous in reducing or avoiding costs associated with use and disposal of potentially toxic solvents and byproducts. Gel materials prepared according to the disclosed methods are suitable for use in environments involving electrochemical reactions, for example as an electrode material within a lithium-ion battery.

Abstract: The present disclosure is directed to methods of forming polyimide gels. The methods generally include forming a polyamic acid and dehydrating the polyamic acid with a dehydrating agent in the presence of water. The resulting polyimide gels may be converted to polyimide or carbon xerogels or aerogels. The methods are advantageous in providing rapid or even instantaneous gelation, which may be particularly useful in formation of beads comprising the polyimide gels. Polyimide or carbon gel materials prepared according to the disclosed method are suitable for use in environments containing electrochemical reactions, for example as an electrode material within a lithium-ion battery.

Abstract: Three-dimensional nanoporous aerogels and suitable preparation methods are provided. Nanoporous aerogels may include a carbide material such as a silicon carbide, a metal carbide, or a metalloid carbide. Elemental (e.g., metallic or metalloid) aerogels may also be produced. In some embodiments, a cross-linked aerogel having a conformal coating on a sol-gel material is processed to form a carbide aerogel, metal aerogel, or metalloid aerogel. A three-dimensional nanoporous network may include a free radical initiator that reacts with a cross-linking agent to form the cross-linked aerogel. The cross-linked aerogel may be chemically aromatized and chemically carbonized to form a carbon-coated aerogel. The carbon-coated aerogel may be suitably processed to undergo a carbothermal reduction, yielding an aerogel where oxygen is chemically extracted. Residual carbon remaining on the surface of the aerogel may be removed via an appropriate cleaning treatment.

Abstract: Nanoporous carbon-based scaffolds or structures, and specifically carbon aerogels and their manufacture and use thereof are provided. Embodiments include a silicon-doped anode material for a lithium-ion battery, where the anode material includes beads of a polyimide-derived carbon aerogel. The carbon aerogel may further include silicon particles and accommodates expansion of the silicon particles during lithiation. The anode material provides optimal properties for use within the lithium-ion battery.

Abstract: The present invention discloses novel porous polymeric compositions comprising random copolymers of amides, imides, ureas, and carbamic-anhydrides, useful for the synthesis of monolithic bimodal microporous/macroporous carbon aerogels. It also discloses methods for producing said microporous/macroporous carbon aerogels by the reaction of a polyisocyanate compound and a polycarboxylic acid compound, followed by pyrolytic carbonization, and by reactive etching with CO2 at elevated temperatures. Also disclosed are methods for using the microporous/macroporous carbon aerogels in the selective capture and sequestration of carbon dioxide.