SYNOPSISThe purpose of this research is to prepare high solute permeability membranes for hemodialysis by plasma depositing hydrophilic monomers onto chemically treated or O2 plasma etched Nylon 4 substrate. The factors that affect the performances of membranes, such as deposition conditions and chemical or plasma etching conditions, were studied. The monomers used in this study were 1-vinyl-2-pyrrolidone ( V P ) , 2-Hydroxyethyl methacrylate (HEMA), and Methyl methacrylate (MMA) . The permeabilities of NaCl, urea, vitamin BIZ, and albumin were measured, as were the water content, hydration, diffusivity, partition coefficient, and protein adsorption ratio of fibrinogen to albumin by membrane surface of plasma deposited membranes. plasma modified to improve the surface energy, water content, and transport fluxes for dialysis by Lai et a1.5*6 Lai et al. used plasmas to induce hydrophilic monomers to graft onto Nylon 4 membranes for reverse osmosis desalination. Plasma deposition has been utilized to increase surface energy, plasma polymerization, etching in membrane modification, 7-9 and biomedical applications."-" Plasma polymerized surfaces are in both smooth and textured configurations, and tend to be relatively nonthrombogenic.12The purpose of this study is to improve the permeability hemodialysis and the mole ratio of adsorbed fibrinogen t o adsorbed albumin of membranes by plasma depositing the hydrophilic monomers, such as 1-Vinyl-2-pyrrolidone (VP) , 2-Hydroxyethyl methacrylate ( HEMA), and Methyl methacrylate ( MMA) , onto chemical or O2 plasma treated Nylon 4 substrate. The dialysis permeability, hydration, water content, diffusion coefficient, partition coefficient, and protein absorption ratio of fibrinogen to albumin by membrane surface of plasma deposited membranes are measured. The solutes 1431