Abstract:

A structure-switchable monomer N,N-dimethyl-N-(ethoxycarbonylmethyl)-N[2'-(methacryloyloxy)ethyl]-ammoniumbromide(CBMA-1C2) was synthesized. The polymer brush of PCBMA-1C2 was fabricated on the polypropylene(PP) surface by photografting polymerization method, which could be hydrolyzed in alkaline aqueous solution to produce the polymer brush PCBMA surface(PP-PCBMA) with zwitterionic structure. The attenuated total reflectance infrared(ATR-IR) spectroscopy and X-ray photoelectron spectroscopy(XPS) were used to characterize the modified PP surface. The hydrophilia/hydrophobicity of PP before and after photografting and hydrolysis were measured by static contact angle measurements. The uniformity of surface elemental composition was monitored by dynamic contact angle measurements. The effect of hydrophilicity/hydrophobicity and charge types of the surface on the interactions between biological molecules and material surface were assessed by protein adsorption and platelet adhesion experiment. The results show that the PP-PCBMA-1C2 and PP-PCBMA have good hydrophilic properties. However, the difference in surface charge types made their protein adsorption and platelet adhesion behavior greatly different. The results suggested that the PP surface with good hydrophilicity and zwitterionic structure exhibited strong resistance of protein adsorption and platelet adhesion.

Key words: Photografting, Polymer brush, Surface modification, Protein adsorption, Platelet adhesion