Semipermeable thin-film membranes comprising siloxane, alkoxysilyl and aryloxysilyl oligomers and copolymers

A thin-film composite separation membrane comprising a microporous polymeric support having a thin polymeric semipermeable film formed on the surface of said support, said film comprising the polycondensation reaction product of two complementary polyfunctional compounds, at least one of which is selected from a group consisting essentially of siloxanes, alkoxysilanes, and aryloxysilanes, each of said complelemtary polyfunctional compounds having at least two functional groups selected from a member of Group A or Group B:

• ______________________________________ Group A Group B ______________________________________ --COX --NHR.sub.h --SO.sub.2 X --OH --NCO --SH --POXR.sub.o --NR.sub.h COX ______________________________________
• where X is halide;
• R.sub.o is selected from alkyloxy and substituted alkyloxy containing 1 to 18 carbons in the carbon chain, alkyl and substituted alkyl containing from 1 to 18 carbons in the carbon chain, cycloakyl, substituted cycloalkyl, and substituted heterocycloalkyl, aryl and substituted aryl;
• R.sub.h is selected from hydrogen and R.sub.o ;
• provided that when said at least two functional groups are selected from group A for one of said complementary polyfunctional compounds, said at least two functional groups are selected from group B for the other of said complementary polyfunctional compounds, and vice-versa;
• and further provided that when at least one of said complementary polyfunctional compounds is a siloxane and the functional group from group A is --NCO, the functional group from group B is not --NHR.sub.h.