PVDF/PVDF-g-PACMO blend hollow fiber membranes for hemodialysis: preparation, characterization, and performance

A novel approach to improve the biocompatibility of poly(vinylidene fluoride) (PVDF) hollow fiber membrane for hemodialysis is provided. A copolymer (PVDF-g-PACMO) containing the main chain of PVDF and amphiphilic side chains of polyacryloylmorpholine (PACMO) was blended with PVDF powder by a certain proportion and then was cast into a hollow fiber membrane via non-solvent induced phase separation (NIPS). The structure and performance of prepared membranes were characterized by X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), mechanical testing, water contact angle measurement, multi-cycle filtration experiments, blood compatibility testing and dialysis simulation experiment. A higher weight ratio of PVDF-g-PACMO endows the blend membrane with larger membrane surface micro pores and a better hydrophilicity. Moreover, a high pure water flux and an improved blood compatibility with good dialysis property were obtained by enhancing weight ratio of PVDF-g-PACMO. Especially, when the weight ratio of PVDF-g-PACMO was 1/1 (i.e., 50/50), the water flux reached 200 L m(-2) h(-1) and the rejection ratio of BSA was more than 90%, where the urea and lysozyme clearance rate was 80% and 62%, respectively. All the results indicate that PVDF/PVDF-g-PACMO blend hollow fiber membrane is promising to be applied in the field of hemodialysis.