The present invention is directed to a process for preparing a porous material, at least compris-ing the steps of providing a mixture (I) comprising a composition (A) at least comprising at least one polyfunctional isocyanate as component (ai) and at least one mineral acid (aa), and a sol-vent (B), reacting the components in the composition (A) obtaining an organic gel, and drying of the gel obtained. The invention further relates to the porous materials which can be obtained in this way and the use of the porous materials as thermal insulation material and as catalysts.

A (super)hydrophobic isocyanate based organic aerogel/xerogel/cryogel having a water contact angle of at least 90 comprising: a cross-linked porous network structure made of polyurethane and/or polyisocyanurate and/or polyurea, and hydrophobic compounds having before the gelling step at least one isocyanate-reactive group and no isocyanate groups
Characterized in that said hydrophobic compounds are covalently bonded within the porous network of the aerogel/xerogel/cryogel and wherein said bondings are created during the gelling step of the formation of the isocyanate based organic aerogel/xerogel/cryogel cross-linked porous network structure.

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.

Aerogel particles and a method of making the same are revealed. The method includes the steps of (a) adding a siloxane compound containing methyl groups and a surfactant into water, mixing well and carrying out hydrolysis to get a mixed aqueous solution; (b) mixing the mixed aqueous solution with 0.1-0.2M ammonium hydroxide and a remaining percentage of an organic solvent, and stirring the mixture under nitrogen atmosphere for emulsion polymerization to get a water-in-oil (w/o) lotion; and (c) removing the organic solvent and drying the w/o lotion to get aerogel particles. Thereby the aerogel particles are produced by the present method without hydrophobic treatment and solvent exchange. Therefore the cost and time used for preparing the aerogel particles are saved.

A method of preparing aerogels/nonwoven composites fireproof and heat-insulating materials with a hydrophobic or hydrophilic surfaces and includes steps as follows. A mixture solution in which alkoxysilane, silicones and silane coupling agents are mixed and stirred is instilled by acidic catalysts for a hydrolysis reaction during which a silane coupling agent solution is added for continuous stirring; a hydrous alkali catalytic (anhydrous alkali catalytic) organic solution is added in the mixture solution for a condensation reaction and development of a silicones-silica aerogels-silane coupling agents aerogel mixture solution; a non-woven felt is impregnated with the mixture solution for development of soft hydrophobic (hydrophilic) aerogels/nonwoven composites fireproof and heat-insulating materials after curing and natural drying. The aerogels/nonwoven composites materials with softness and surface hydrophobicity/hydrophilicity available in mass production are applicable to thermal-insulating materials for high-temp industrial facilities or indoor heat-insulating and fireproof panels of a building structure.

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.

Nanoporous three-dimensional networks of polyurethane particles, e.g., polyurethane aerogels, and methods of preparation are presented herein. Such nanoporous networks may include polyurethane particles made up of linked polyisocyanate and polyol monomers. In some cases, greater than about 95% of the linkages between the polyisocyanate monomers and the polyol monomers are urethane linkages. To prepare such networks, a mixture including polyisocyanate monomers (e.g., diisocyanates, triisocyanates), polyol monomers (diols, triols), and a solvent is provided. The polyisocyanate and polyol monomers may be aliphatic or aromatic. A polyurethane catalyst is added to the mixture causing formation of linkages between the polyisocyanate monomers and the polyol monomers. Phase separation of particles from the reaction medium can be controlled to enable formation of polyurethane networks with desirable nanomorphologies, specific surface area, and mechanical properties. Various properties of such networks of polyurethane particles (e.g., strength, stiffness, flexibility, thermal conductivity) may be tailored depending on which monomers are provided in the reaction.

Cross-linked sol-gel like materials and cross-linked aerogels, as well as methods for making such cross-linked sol-gel like materials and cross-linked aerogels are described.

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.

Porous cross-linked partially aliphatic polyimide networks are provided. The polyimide networks comprise a polyamic acid oligomer that (i) comprises a repeating unit of a dianhydride and a diamine and terminal functional groups, (ii) has an average degree of polymerization of 10 to 70, (iii) has been cross-linked via a cross-linking agent, comprising three or more cross-linking groups, at a balanced stoichiometry of the cross-linking groups to the terminal functional groups, and (iv) has been chemically imidized to yield the porous cross-linked polyimide network. The polyimide networks are partially aliphatic based on (a) the diamine comprising a first diamine and a second diamine, wherein the first diamine comprises a linear aliphatic backbone chain, and the second diamine does not, and/or (b) the dianhydride comprising a first dianhydride and a second dianhydride, wherein the first dianhydride comprises a linear aliphatic backbone chain, and the second dianhydride does not.