Abstract: An ultra thin anionic exchange layer containing —NH₂ and —CONH₂ was deposited on the surface of Nafion^TMmembrane. This layer was deposited from ethylene and ammonia using a glow discharge plasma polymerization technique. The SEM, ATR(attenuated total reflection) spectra and XPS(X-ray photoelectron spectroscopy) showed that the resulted plasma polymers containing —NH₂ and —CONH₂ was about 05 μm thick. The proton perm selectivity of plasma modified Nafion^TMmembrane was expressed by t_Cu, the transference number of the Cu ²⁺ ion through the membrane which was determined by using Nafion^TMmembrane as the separator in a typical two compartment cell(025 mol/L CuCl₂0 5mol/L HCl ｜plasma modified Nafion^TMmembrane｜1 mol/L HCl). Pretreatment of the Nafion^TMmembrane by oxygen sputtering enhanced the adhesion of plasma polymer onto its surface. The plasma treated membrane exhibited a high perm selectivity and its resistance in₁ mol/L HCl was only a little bit higher than Nafion^TMmembrane(<0.5 Ω·cm²).

Key words: Nafion^TM membrane, Plasma polymerization, Surface modification, Resistance