writer：Xiang Shen, Yiping Zhao, Li Chen, Xia Feng, Duo Yang, Qiang Zhang, Dan Su
keywords：Take-up Speeds
source：期刊
specific source：Polymer Engineering and Science
Issue time：2013年
 Graft copolymer (PVDF-g-PNIPAAm) having poly(vinylidene fluoride) (PVDF) backbones and poly(N-isopropylacrylamide) (PNIPAAm) side chains was synthesized via radical copolymerization and its hollow fiber membrane was fabricated from dry–wet spinning technique with N,N-dimethylformamide as the solvent and poly(ethylene glycol) (10,000) as the additive. The effects of spinning condition (take-up speeds) on the structures and performances of resulting fiber membranes were systematically considered. The structures and performances of fiber membranes were characterized by element analysis, X-ray photoelectron spectroscopy, water contact angle measurement, scanning electron microscope, atom force microscope, and filtration experiments. The results indicate that PNIPAAm side chains tended to enrich on the membrane surface and pore surface and especially tended to aggregate on the inner surface due to the effect of bore fluid. The hollow fiber membrane exhibits an obvious temperature-sensitive property. The pure water flux increases remarkably around 328C, while the retention of albumin egg decreases accordingly, when the permeation temperature rises from 20 to458C. As the take-up speed increases, both the inner and outer diameters of fiber membranes decrease. A higher take-up speed favors higher pure water permeation flux, which allows larger molecules to permeate through the fiber membrane.