This invention relates to the composition of an integrally-layered polymeric membrane and a process for utilizing the integrally-layered polymeric membrane components of a feedstream. More particularly, but not by way of limitation, this invention relates to the composition of an integrally-layered polymeric membrane and a process for utilizing the integrally-layered polymeric membrane in the separation of aromatics from a hydrocarbon based feedstream. The polymeric membranes of the present invention are fabricated by chemically crosslinking adjacent polymer membrane layers of the same or differing copolymer solutions to produce an integrally-layered polymeric membrane with improved separations properties.