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.

A chemical vapor deposition method for fluorine-containing carbon materials preparation provided. The claimed method comprises treating of carbons with fluorocarbons or derivatives that passes at a moderate high temperature. The fluorine-containing carbon materials show hydrophobicity, high thermal stability and can be used as catalysts support, lithium battery anodes, and hydrophobic materials or as surface precursor. Surface fluorine characterized by intensive signal in the XPS spectrum, found in a range of 685-687 eV. Obtained fluoro-containing functionalities is stable at a temperature about 1000° C.

A method of making a carbon foam comprises subjecting a precursor composition comprising an amount of at least partially decomposed lignin to a first pressure for a first time, optionally, while heating the precursor composition to a first temperature; heating the compressed precursor composition to a second temperature for a second period of time while subjecting the compressed precursor composition to a second pressure to further decompose the at least partially decomposed lignin and to generate pores within the compressed precursor composition, thereby providing a porous, decomposed precursor composition; and heating the porous, decomposed precursor composition to a third temperature for a third time to carbonize, and optionally, to graphitize, the porous, decomposed precursor composition to provide the carbon foam. Also provided are the carbon foams and composites made from the carbon foams.

A method of making a carbon foam comprises subjecting a precursor composition comprising an amount of at least partially decomposed lignin to a first pressure for a first time, optionally, while heating the precursor composition to a first temperature; heating the compressed precursor composition to a second temperature for a second period of time while subjecting the compressed precursor composition to a second pressure to further decompose the at least partially decomposed lignin and to generate pores within the compressed precursor composition, thereby providing a porous, decomposed precursor composition; and heating the porous, decomposed precursor composition to a third temperature for a third time to carbonize, and optionally, to graphitize, the porous, decomposed precursor composition to provide the carbon foam. Also provided are the carbon foams and composites made from the carbon foams.

A method for the large-scale synthesis of a zeolite-templated carbon (ZTC). The method includes the steps of: introducing a bed material comprising a zeolite to a fluidized bed reactor and heating the bed material to a temperature between 550° C. and 800° C.; fluidizing the bed material with a fluidizing gas and maintaining the temperature of the bed material between 550° C. and 800° C.; introducing an organic carbon precursor while fluidizing the zeolite for a period of time such that carbon is deposited on the zeolite by chemical vapor deposition to produce a zeolite-carbon composite; and treating the zeolite-carbon composite with an acid solution such that the zeolite template is dissolved and the ZTC is obtained.

A method for the large-scale synthesis of a zeolite-templated carbon (ZTC). The method includes the steps of: introducing a bed material comprising a zeolite to a fluidized bed reactor and heating the bed material to a temperature between 550° C. and 800° C.; fluidizing the bed material with a fluidizing gas and maintaining the temperature of the bed material between 550° C. and 800° C.; introducing an organic carbon precursor while fluidizing the zeolite for a period of time such that carbon is deposited on the zeolite by chemical vapor deposition to produce a zeolite-carbon composite; and treating the zeolite-carbon composite with an acid solution such that the zeolite template is dissolved and the ZTC is obtained.

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.

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.

Silicon particles for active materials and electro-chemical cells are provided. The active materials comprising silicon particles described herein can be utilized as an electrode material for a battery. In certain embodiments, the composite material includes greater than 0% and less than about 90% by weight of silicon particles. The silicon particles have an average particle size between about 0.1 μm and about 30 μm and a surface including nanometer-sized features. The composite material also includes greater than 0% and less than about 90% by weight of one or more types of carbon phases. At least one of the one or more types of carbon phases is a substantially continuous phase.

Silicon particles for active materials and electro-chemical cells are provided. The active materials comprising silicon particles described herein can be utilized as an electrode material for a battery. In certain embodiments, the composite material includes greater than 0% and less than about 90% by weight of silicon particles. The silicon particles have an average particle size between about 0.1 μm and about 30 μm and a surface including nanometer-sized features. The composite material also includes greater than 0% and less than about 90% by weight of one or more types of carbon phases. At least one of the one or more types of carbon phases is a substantially continuous phase.