Preparation of porous membranes grafted with poly(spiropyran‐containing methacrylate) and photocontrol of permeability

Abstract
Graft copolymerization of spiropyran‐containing methacrylate (SPMMA) and acrylamide (AM) onto the surface of a porous polymer membrane was carried out. The permeability of the graft membrane varied with ultraviolet (UV) ‐ or visible‐light irradiation. It was found that the change by UV‐light irradiation of the permeability of the H2O/CH3OH mixture through the SPMMA/AM‐grafted membrane is related to the change by UV‐light irradiation of the solubility, i.e., the chain extension, of the graft copolymer in the mixed solvent. When the free SPMMA/AM copolymer becomes insoluble in the H2O/CH3OH mixture by UV‐light irradiation, the permeability of the H2O/CH3OH mixture through the SPMMA/AM‐grafted membrane is increased. © 1994 John Wiley & Sons, Inc.