PREPARATION OF SURFACE-MODIFIED STIMULI-RESPONSIVE POLYMERIC MEMBRANES BY PLASMA AND ULTRAVIOLET GRAFTING METHODS AND THEIR RIBOFLAVIN PERMEATION

Acrylic monomers were grafted on the surface of commercial polyamide m embranes using plasma polymerization and ultraviolet irradiation techn iques. Graft reaction was confirmed by X-ray photoelectron spectra. Gr afting yield increased with plasma and ultraviolet exposure time. Perm eation of riboflavin through graft membranes was investigated. Poly(ac rylic acid-g-amide) membranes showed a decrease in permeability of rib oflavin at pH 4-5, while poly(methacrylic acid-g-amide) membranes exhi bited decreased permeability at pH 6-7 regardless of the grafting meth ods. N-isopropylacrylamide-grafted polyamide membrane showed a tempera ture-dependent permeation of riboflavin.