Poly(vinylidene fluoride) (PVDF) membrane is widely used in water purification and wastewater treatment. In present paper, thermally induced phase separation (TIPS) was employed, and maleic acid dibutyl ester (DBM), a new diluent, was introduced for PVDF membrane preparation. Phase diagram and the effects of polymer concentration and quenching temperature on the structure, morphologies, properties, and performances of PVDF membranes were investigated. During the quenching process of PVDF/DBM system, liquid-liquid phase separation happened, and PVDF membranes with a bi-continuous structure were fabricated. What is interesting is that the liquid-liquid phase separation region was much wider than other PVDF/diluent systems. Thus, it is possible to fabricate PVDF membrane with a bi-continuous structure at high polymer concentrations, without stretching or additives. With the increase in polymer concentration and quenching temperature, mean pore size and pure water flux of the PVDF membrane decreased. Tensile stress of the prepared PVDF membranes reached to 6.18 MPa, because the wide liquid-liquid phase separation region induced a bi-continuous structure when the concentration of the PVDF membrane was at around 30%.

聚偏二氟乙烯（PVDF）膜广泛用于水净化和废水处理。在本文中，采用热诱导相分离（TIPS），并引入了一种新的稀释剂马来酸二丁酯（DBM）来制备PVDF膜。研究了相图以及聚合物浓度和淬火温度对PVDF膜结构，形貌，性能和性能的影响。在PVDF / DBM体系的淬火过程中，发生了液-液相分离，并制备了具有双连续结构的PVDF膜。有趣的是，液相-液相分离区域比其他PVDF /稀释剂系统宽得多。因此，可以在高聚合物浓度下制造具有双连续结构的PVDF膜，没有拉伸或添加剂。随着聚合物浓度和淬火温度的增加，PVDF膜的平均孔径和纯水通量降低。制备的PVDF膜的拉伸应力达到6.18MPa，这是因为当PVDF膜的浓度为约30％时，宽的液相-液相分离区域引起了双连续结构。