对于正渗透过程来说,膜的结构参数是衡量内浓差极化的重要指标.本文首先研究了基底对相转化法制备的基膜结构和性能的影响,并进一步研究了基膜结构对聚酰胺TFC膜正渗透性能的影响.结果表明,基底的亲水性和多孔结构分别是影响基膜结构的两个重要因素,其中多孔基底在提高基膜底面开孔率和增大膜断面指状孔结构和贯通性方面影响更大;分别以1mol/L的NaCl溶液和去离子水作为汲取液和原料液时,在多孔基底所制备的基膜上形成的复合膜的正渗透水通量可达到38.6L/(m^2·h),反向盐通量为8.0g/(m^2·h),相比于传统以玻璃板为基底所形成的复合膜,膜的结构参数从386.0μm下降到172.5μm.
The structural parameter of the membrane is an important standard to measure the internal concentration polarization in forward osmosis process. In this paper, the impacts of different substrates on the porous structure of the polysulfone support layer and the performance of TFC-FO membranes formed on different support layers were investigated. Results showed that the hydrophilicity and the porous structure of the substrate are two important factors which influence the structure of the polysulfone support layer. Further more, the porous substrate exhibits better performance in improving the bottom surface porosity and the permeability of finger-like pore in the middle. The FO membrane prepared on the support layer, which is cast on the porous substrate, shows an excellent flux of 38. 6 L/(m^2·h) and a reverse salt flux of 8. 0 g/(m^2 ·h) under FO mode for 1 mol/L NaC1 draw solution from a de-ionized water feed solution. Compared with the traditional TFC-FO membrane when glass plate is used as thecasting substrate, the structural parameter (S) of the membrane decreased from 386.0μm to 172. 5 μm.