Abstract: Layers comprising a molecular sieve layer on a porous or non-porous support, having uniform properties and allowing high flux are prepared from colloidal solutions of zeolite or other molecular sieve precursors (particle size less than 100 nm), by deposition, e.g., by spin or dip-coating, or by in situ crystallization.

Abstract: The invention is related to a zeolite membrane composite composition comprising a first zeolite or zeolite-like layer, a second independently selected catalytic, permselective, or combined catalytic-permselective layer, and a porous support, the porous support having a first surface in contact with the first zeolite layer and a second surface in contact with the second layer. In another embodiment, the invention is directed toward a zeolite membrane composite composition comprising a supported zeolite or zeolite-like layer, the support having a catalytic functionality contained thereon.

Abstract: The present invention provides for microporous ceramic materials having a surface area in excess of 50 m2/gm and an open microporous cell structure wherein the micropores have a mean width of less than 20 Angstroms and wherein said microporous structure comprises a volume of greater than about 0.015 cm3/gm of the ceramic. The invention also provides for a preceramic composite intermediate composition comprising a mixture of a ceramic precursor and finely divided particles comprising a non-silicon containing ceramic, carbon, or an inorganic compound having a decomposition temperature in excess of 400° C., whose pyrolysis product in inert atmosphere or in an ammonia atmosphere at temperatures of up to less than about 1100° C. gives rise to the microporous ceramics of the invention. Also provided is a process for the preparation of the microporous ceramics of the invention involving pyrolysis of the ceramic intermediate under controlled conditions of heating up to temperatures of less than 1100° C.

Abstract: The present invention is directed towards compositions of two or more zeolite layers. The compositions of the invention include zeolite compositions that are themselves catalytic as well as zeolite compositions used in combination with non-zeolite catalytic materials. The compositions may include a porous support.

Abstract: Compositions useful in separating molecules or catalytic conversions comprise a substrate, a zeolite or zeolite-like layer, a selectivity enhancing coating in contact with the zeolite layer and optionally a permeable intermediate layer in contact with the substrate the zeolite layer being in contact either with the substrate or the optional intermediate layer.

Abstract: The present invention is an improvement in a separation process. When molecular sieve membranes are used in a separation process transport flux decays over time. It has been discovered that the presence of hydrogen in the feed stream, permeate stream, or feed stream when present, either alone or in combination, causes a reduction in flux decay.

Abstract: The present invention provides for microporous ceramic materials having a surface area in excess of 70 m.sup.2 /gm and an open microporous cell structure wherein the micropores have a mean width of less than 20 Angstroms and wherein said microporous structure comprises a volume of greater than about 0.03 cm.sup.3 /gm of the ceramic. The invention also provides for a preceramic composite intermediate composition comprising a mixture of a ceramic precursor and finely divided silicon carbide or silicon nitride, whose pyrolysis product in inert atmosphere or in an ammonia atmosphere at temperatures of up to less than about 1100.degree. C. gives rise to the microporous ceramics of the invention. Also provided is a process for the preparation of the microporous ceramics of the invention involving pyrolysis of the ceramic intermediate under controlled conditions of heating up to temperatures of less than 1100.degree. C. to form a microporous ceramic product.

Abstract: Membranes useful in separating moleculres or catalytic conversions comprise a substrate, a zeolite or zeolite-like layer, a selectivity enhancing coating in contact with the zeolite layer and optionally a permeable intermediate layer in contact with the substrate the zeolite layer being in contact either with the substrate or the optional intermediate layer.

Abstract: The present invention provides for microporous ceramic materials having a surface area in excess of 100 m.sup.2 /gm and an open microporous cell structure wherein the micropores have a mean width of less than 20 Angstroms and wherein said microporous structure comprises a volume of greater than about 0.05 cm.sup.3 /gm of the ceramic. The pyrolysis product of ceramic precursor oligomers or polymers having a number average molecular weight in the range of from about 200 to about 100,000 g/mole in an ammonia atmosphere at temperatures of up to less than about 1200.degree. C. gives rise to the microporous ceramics of the invention. Also provided is a process for the preparation of the microporous ceramics of the invention involving pyrolysis of the ceramic precursor under controlled conditions of heating and with intermediate hold times, up to temperatures of less than 1200.degree. C., preferably less than 1000.degree. C., to form a microporous ceramic product.

Abstract: The instant invention is directed toward a process for enhancing the permselective properties, selectively sealing defects and pinholes, controllably altering the pore size and stabilizing the permselective properties of articles having apperatures therein comprising the steps of: simultaneously contacting an article having a first and second surface, said first and second surfaces being capable of passing ozone and silicon compounds therethrough and said first and second surfaces being oriented such that said silicon compounds and ozone can react across said first and second surfaces, with ozone on said first surface and a silicon compound on said second surface and wherein said contacting is conducted for a time and at a temperature and pressure sufficient to allow said ozone and said silicon compound to form a silicon oxide.

Abstract: The present invention provides for microporous ceramic materials having a surface area in excess of 70 m.sup.2 /gm and an open microporous cell structure wherein the micropores have a mean width of less than 20 Angstroms and wherein said microporous structure comprises a volume of greater than about 0.03 cm.sup.3 /gm of the ceramic. The invention also provides for a preceramic composite intermediate composition comprising a mixture of a ceramic precursor and finely divided silicon carbide or silicon nitride, whose pyrolysis product in inert atmosphere or in an ammonia atmosphere at temperatures of up to less than about 1100.degree. C. gives rise to the microporous ceramics of the invention. Also provided is a process for the preparation of the microporous ceramics of the invention involving pyrolysis of the ceramic intermediate under controlled conditions of heating up to temperatures of less than 1100.degree. C. to form a microporous ceramic product.