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US 6,440,309 B1Granted
Ceramic-supported polymer (CSP) pervaporation membrane
OwnerYoram Coheninventor
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OwnerYoram Coheninventor
Estimating the term…
A ceramic-supported polymer membrane is disclosed where a porous ceramic membrane support of average pore size no larger than 500 Å is activated by attaching a vinyl terminated lower alkoxy silane to the surface of the ceramic membrane pores. The resulting membrane retains at least 10 micromoles of the vinyl terminated loweralkoxy silane per square meter of the ceramic membrane surface. A method for optimizing the amount of vinyl loweralkoxy silane reacted with the ceramic support surface is also disclosed. The large amount of vinyl terminated loweralkoxy silane which is chemically bonded to the surface of the ceramic porous support produces activated ceramic membrane support surface which is useful for graft polymerization of vinyl monomers onto the porous ceramic membrane support surface. A vinyl monomer is then graft polymerized onto the activated membrane. The resulting ceramic-supported polymer membrane is useful for pervaporation separation of liquids mixtures that are sufficiently different in their vapor pressure.
A pervaporation membrane consisting essentially of a porous ceramic support of pore size 500 angstroms or less containing surface hydroxyls or having been hydrolyzed to create surface hydroxyls and having been treated to contain surface water in the amount equivalent of 2-24 monolayers of water, said surface having vinyl loweralkoxy silane or vinythydroxy silane chemically attached to the external surface and/or pore surface in an amount of at least 10 micromoles of said vinyl loweralkoxy silane or vinyl hydroxysilane per square meter of said ceramic membrane, said surface activated ceramic support having graft polymerized onto the vinyl alkoxysilane or vinyl hydroxysilane a water insoluble or water soluble vinyl monomer, by free-radical graft polymerization, resulting in terminally and covalently bonded vinyl polymer in an amount of at least 2 milligram of said vinyl polymer per square meter of said ceramic membrane support surface.
Dependencies are inferred from the claim text.