采用聚偏氟乙烯(PVDF)中空纤维膜对水中的溶解氧进行了脱氧研究,考察了膜表面结构对脱氧效率的影响。通过改变内凝固浴的组成来改变膜的表面结构。在测定脱氧效率的同时,对不同内凝固浴下的中空纤维膜内表面结构进行了场发射电镜扫描(FE-SEM),并分别测定了中空纤维膜的孔径、透气系数以及力学性能。结果表明,随着内凝固浴中溶剂DMAc含量的增大,膜内表面开孔结构变大,表面变得粗糙,这种结构使得膜的透气系数增大,传质系数和脱氧效率提高。
Deoxidizing performance of polyvinylidene fluoride (PVDF) hollow fiber membrane with different microporous structure was studied. The PVDF membranes had been fabricated using four different internal coagu-lants including water, 60%, 70% and 75% DMAc solutions which had a significant impact on surface morphology under the same spinning condition. The membrane surface morphology was identified by scanning electron microscopy (SEM) and the pore size, permeability coefficient and mechanics performance of membrane were al- so tested. Results show that a bigger surface roughness on the membrane can be obtained using 75 % DMAc in internal coagulants. Gas permeation tests demonstrate that PVDF membrane with a bigger surface roughness has a higher permeability coefficient. This kind of PVDF hollow fiber membrane turns out to have a higher overall mass transfer coefficient and deoxidizing efficiency.