Abstract: In this paper, low-temperature oxygen plasma method was used to modify the surface of PP(polypropylene) microporous membranes. The influence of oxygen plasma on the chemical structure and physical performance of the membrane was investigated with SEM, XPSand IRspectra. The results of XPSand IRshowed that polar groups, —OH, —COOH, C=O were created on these membrane surfaces. The groups —OH and —COOH were useful for activation and grafting process for affinity membrane with Cu²⁺ as a metal-chelating ligand. The influence of plasma treatment condition on the adsorbability of affinity membrane for lysozyme was carried out. The optimal adsorbability of lysozyme was 8μg/cm² on the affinity membrane prepared for 20 min and under 68 Wplasma condition.

Key words: Low-temperature oxygen plasma, Polypropylene membrane, Metal-chelating ligand, Affinity adsorption, Lysozyme