In this work, the poly(vinylidene fluoride) (PVDF) hollow fiber membranes with switchable pore size were fabricated by melt-spinning and stretching (MS–S) process based on a completely green and sustainable route. The membrane preparation process and pore formation mechanism were discussed and investigated in detail. Meanwhile, the effect of stretching ratio on the membrane structure and property was studied based on scanning electron microscopy (SEM), pore size distribution, N₂ flux, pure water flux, mechanical property and so on. The prepared membranes with different stretching ratios exhibited excellent tensile strength in the range from 23.0 to 62.6 MPa. The mean pore size of the prepared membranes with stretching 100 % (M-100) was about 0.317 μm, which showed a high dye rejection (<93.9 %) for Direct Black 19. Specifically, there were not any organic solvent and low-molecular-weight diluent used during the preparation process. The recycled PEO and water were obtained after treating the wastewater by membrane filtration. In addition, the recycled PEO could be reused as pore forming agent, which could achieve completely green and sustainable membrane preparation process.

在这项工作中，基于完全绿色且可持续的路线，通过熔融纺丝和拉伸（MS-S）工艺制造了孔径可变的聚偏二氟乙烯（PVDF）中空纤维膜。对膜的制备过程和成孔机理进行了详细的探讨。同时，基于扫描电镜，孔径分布，N ₂，研究了拉伸比对膜结构和性能的影响。通量，纯净水通量，力学性能等。所制备的具有不同拉伸比的膜在23.0至62.6MPa的范围内表现出优异的拉伸强度。制备的拉伸率为100％（M-100）的膜的平均孔径约为0.317μm，这表明直接黑19具有很高的染料截留率（<93.9％）。特别地，没有任何有机溶剂和低分子制备过程中使用的稀释剂。通过膜过滤处理废水后，可得到回收的PEO和水。此外，回收的PEO可重新用作造孔剂，从而实现完全绿色和可持续的膜制备过程。