用于反渗透复合膜的海绵状结构支撑膜制备研究

Investigation of sponge-like substrates for preparation of reverse osmosis composite membranes

通过调节铸膜液中聚砜浓度和非溶剂含量,浸没沉淀法制备海绵状结构的支撑膜,并在支撑膜上界面聚合制备聚酰胺反渗透复合膜。分别对支撑膜及反渗透复合膜的结构和性能进行表征,考察聚砜浓度对支撑膜结构和性能的影响,以及不同结构支撑膜对反渗透复合膜结构和性能的影响。结果显示,随着聚砜浓度的增加,支撑膜表面孔径和孔隙率下降,断面结构变致密,耐压性增强。在不同支撑膜上制备的反渗透复合膜具有不同的通量和脱盐率。综合考虑支撑膜及反渗透复合膜的性能,以聚砜浓度为15%制备的海绵状结构支撑膜更适于作为制备反渗透复合膜的支撑层。

A series of sponge-like polysulfone substrates were fabricated by adjusting the content of PSf and water in the casting solutions. Then, the polyamide reverse osmosis composite membranes were preparedvia interfacial polymerization between m-phenylenediamine and trimethyl chloride over the polysulfone substrates. The resulting substrates and reverse osmosis membranes were characterized to investigate the influence of the polysulfone concentration on the substrates properties and the effect of the substrates properties on the polyamide reverse osmosis membranes. The results showed that with increasing PSf concentration, the average surface pore size and porosity of the substrates decreased, and the resistance ability to compaction enhanced. Besides, the reverse osmosis composite membranes prepared by using different PSf substrates showed different flux and salt rejection. Considering the properties of the substrates and the polyamide reverse osmosis composite membranes, sponge-like substrate by using 15%（mass） polysulfone concentration was suitable for the preparation of reverse osmosis composite membrane.