熔纺-选择性溶胀制备嵌段共聚物多通道中空纤维膜

Selective swelling of melt-spun block copolymers has been demonstrated to be a clean process in the manufacture of hollow-fiber membranes (HFMs). However, the performances of as-prepared HFMs remain to be improved. In this work, the multi-bore configuration in HFMs to improve their performances was constructed. The spin 3-bore and 7-bore hollow-fibers using polysulfone-block-poly(ethylene glycol) (PSF-b-PEG) were melted, followed by the axial stretching and selective swelling. The influence of the bore numbers, swelling conditions and the stretching percentage on the morphology, permeance, rejection and pressure resistance of as-prepared MHFMs was investigated. Thanks to the mutual support of the wall thickness, the permeability and pressure resistance of the MHFMs were better than those of the single-bore HFMs. Besides, the membrane properties could be effectively controlled in a wide range by adjusting the stretching percentage and swelling conditions. It was found that the permeance of 3HFMs prepared in stretching conditions could reach 20 times higher than that of stretched single-bore HFMs with similar rejection performance. This work was expected to greatly improve the clean preparation of high-performance block copolymer hollow-fiber membranes.