One aspect of the invention is a compound of formula (I) R.sub.o-[L-(C.sub.qH.sub.2qS).sub.pC.sub.rH.sub.2rR.sub.f].sub.2 (I) wherein R.sub.o is a divalent organic group having 2 to 40 carbon atoms; L is a linking group selected from --NHC(O)NH-- or --C(O)NH-- wherein the left side of the linking group is bonded to R.sub.o; p is an integer of 0 or 1; q is an integer of 2 to 10; r is an integer of 1 to 10; and R.sub.f is a linear or branched C.sub.1-C.sub.6 perfluoroalkyl group. Another aspect of the invention is a composite material comprising a porous support and a porous nanoweb, wherein said porous nanoweb comprises fibrous structures of between about 10 nm and about 1000 nm effective average fiber diameter as determined with electron microscopy; said fibrous structures being comprised of one or more compositions of formula (I). Another aspect of the invention is a method for making a composite material comprising a porous support and a porous nanoweb.