Surface modification of polypropylene microporous membranes with a novel glycopolymer

Membrane-based biomedical processes have increased considerably in recent years. However, the natural disadvantages of common membrane materials, such as hydrophobic surface and poor biocompatibility, cause many side effects in use and cumber further applications. In this work, to meet the requirements of biomedical applications, a novel sugar-containing monomer (D-gluconamidoethyl methacrylate (GAMA)) was grafted on polypropylene microporous membrane (PPMM) with an UV-induced polymerization to improve both the surface hydrophilicity and hemocompatibility. Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy were employed to confirm the surface modification on the membranes. Water contact angle, protein adsorption, and platelet adhesion measurements were used to evaluate the anti-fouling property and the hemocompatibility of the membranes. It was found that the GAMA grafting degree increases reasonably with the increase of GAMA monomer concentration, and then the increase slows down when the GAMA concentration exceeds 40 g/L. At the same time, a 20-25-min UV irradiation is enough for the grafting polymerization. The water contact angle of the modified membrane decreases from 149 to 64 degrees with the increase of GAMA grafting degree from 0 to 6.18 wt %, which indicates a hydrophilic variation of the membrane surface by the grafting of GAMA. Furthermore, the modified membranes show higher water and protein solution fluxes, lower BSA adsorption, and better flux recovery after cleaning than those of the original PPMM. Platelet adhesion experiment also reveals that a more hemocompatible interface can be obtained between the membrane and the biomolecules.