Synergistic action of non-solvent induced phase separation in preparation of poly(vinyl butyral) hollow fiber membrane via thermally induced phase separation
来源期刊：中南大学学报(英文版)2014年第6期
论文作者：Qiu Yun-ren(邱运仁) Qi Jing(漆静) Wei Yu-qing(韦玉清)
文章页码：2184 - 2190
Key words：thermally induced phase separation; hollow fiber membranes; synergistic action; hydrophilic membrane
Abstract: A systematic study of air gap distance effects on the structure and properties of poly(vinyl butyral) hollow fiber membrane via thermally induced phase separation (TIPS) has been carried out. The results show that the hollow fiber membrane prepared at air gap zero has no skin layer; the pore size near the outer surface is larger than that near the inner surface; and the special pore channel-like structure near the outer surface is formed, which is quite different with the typical sponge-like structure caused by TIPS and the finger-like structure caused by non-solvent induced phase separation (NIPS), because of the synergistic action of non-solvent induced phase separation at air gap zero. The pore size gradually decreases from outer surface layer to the intermediate layer, but increases gradually from intermediate layer to the inner surface layer. With the increase of air gap distance, the pore size near the outer surface gets smaller and a dense skin layer is formed, and the pore size gradually increases from the outer surface layer to the inner surface layer. Water permeability of the hollow fiber membrane decreases with air gap distance, the water permeability decreases sharply from 45.50×10-7 to 4.52×10-7 m3/(m2·s·kPa) as air gap increases from 0 to 10 mm at take-up speed of 0.236 m/s, further decreases from 4.52×10-7 to 1.00×10-8 m3/(m2·s·kPa) as the air gap increases from 10 to 40 mm. Both the breaking strength and the elongation increase with the increase of air gap distance. The breaking strength increases from 2.25 MPa to 4.19 MPa and the elongation increases from 33.9% to 132.6% as air gap increases from 0 mm to 40 mm at take-up speed 0.236 m/s.
Qiu Yun-ren(邱运仁), Qi Jing(漆静), Wei Yu-qing(韦玉清)
(School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China)
Abstract:A systematic study of air gap distance effects on the structure and properties of poly(vinyl butyral) hollow fiber membrane via thermally induced phase separation (TIPS) has been carried out. The results show that the hollow fiber membrane prepared at air gap zero has no skin layer; the pore size near the outer surface is larger than that near the inner surface; and the special pore channel-like structure near the outer surface is formed, which is quite different with the typical sponge-like structure caused by TIPS and the finger-like structure caused by non-solvent induced phase separation (NIPS), because of the synergistic action of non-solvent induced phase separation at air gap zero. The pore size gradually decreases from outer surface layer to the intermediate layer, but increases gradually from intermediate layer to the inner surface layer. With the increase of air gap distance, the pore size near the outer surface gets smaller and a dense skin layer is formed, and the pore size gradually increases from the outer surface layer to the inner surface layer. Water permeability of the hollow fiber membrane decreases with air gap distance, the water permeability decreases sharply from 45.50×10-7 to 4.52×10-7 m3/(m2·s·kPa) as air gap increases from 0 to 10 mm at take-up speed of 0.236 m/s, further decreases from 4.52×10-7 to 1.00×10-8 m3/(m2·s·kPa) as the air gap increases from 10 to 40 mm. Both the breaking strength and the elongation increase with the increase of air gap distance. The breaking strength increases from 2.25 MPa to 4.19 MPa and the elongation increases from 33.9% to 132.6% as air gap increases from 0 mm to 40 mm at take-up speed 0.236 m/s.
Key words:thermally induced phase separation; hollow fiber membranes; synergistic action; hydrophilic membrane
