Abstract:

To solve the problem of organic wastewater discharge in the spinning process of membrane preparation, PVDF/GE hollow fiber membranes were prepared by the solvent-free method. The nascent hollow fiber membranes were prepared by melt spinning PVDF, GE and functional particles. The PVDF crystal structure was redesigned by post-stretching and GE synergistic effect. The effects of different stretching ratios on the crystalline transition, mechanical properties and permeation performance of the hollow fiber membranes were investigated. The surface morphology of the hollow fiber membranes with different stretching ratios was observed, and the pore size distribution, mechanical properties and permeation performance of the membranes were tested by a series of instruments. It was found that the transition from α-crystalline to β-crystalline occurred inside the PVDF/GE hollow fiber membranes. The higher the stretching ratio, the more crystalline transformation was observed inside the membranes. Graphene channels were formed by GE inside the hollow fiber membranes, which improved the mechanical properties and permeation performance of the membranes. When the stretching ratio reached 100%, the tensile strength of the hollow fiber membrane was 37.8MPa, the β-crystalline content inside was 68.64% and the oil flux was 965.64L/ (m²·h).

Key words: PVDF, GE, hollow fiber membrane, solvent-free method, β-crystalline

摘要：

为了解决在纺丝制膜过程中有机污水排放问题，采用无溶剂法制备聚偏氟乙烯（PVDF）/石墨烯（GE）中空纤维膜。将PVDF、GE和功能粒子熔融共混制备初生中空纤维膜，利用后拉伸和GE协同作用重新设计PVDF晶体结构，探究不同拉伸比对中空纤维膜晶型转变和力学性能以及渗透性能的影响，观察不同拉伸比中空纤维膜的表面形貌，并利用一系列仪器测试了膜的孔径分布、力学性能和渗透性能。结果表明：制备的PVDF/GE中空纤维膜内部存在α晶型向β晶型转变，拉伸后GE在中空纤维膜内部形成石墨烯通道，拉伸比越大，内部晶型转化越多，中空纤维膜的力学性能和渗透性能越好；当拉伸比达到100%时，中空纤维膜的断裂强度可达37.8MPa，内部β晶型含量为68.64%，煤油通量可达965.64L/(m²·h)。

关键词: 聚偏氟乙烯, 石墨烯, 中空纤维膜, 无溶剂法, β晶型