PEO正渗透膜的制备与表征

摘要

为提高正渗透膜的抗污染性能,以O,O'-二(2-氨基丙基)聚丙二醇-嵌段-聚乙二醇-嵌段-聚丙二醇和均苯三甲酰氯(TMC)为水相、油相反应单体在聚砜基膜上进行界面聚合,制备聚环氧乙烷(PEO)亲水型聚酰胺正渗透膜(PSf-Jeff/TMC复合膜),采用红外光谱、X光电子能谱和水接触角等手段研究选择分离层的化学结构和亲水性能,考察界面聚合时间、反应单体浓度和后处理温度等制备条件对正渗透膜渗透分离性能的影响,并以牛血清蛋白作为污染物分析其抗污染性能.结果表明:聚合时间30 s、TMC质量浓度1.5 mg/mL、水相单体质量分数3％、热处理温度为60℃时所制备的PSf-Jeff/TMC正渗透膜,在1 mol/L氯化钠、室温条件下测得水通量1.75 L/(m2·h),反向盐通量140 g/(m2·h);与间苯二胺复合膜PSf-MPD/TMC相比,PSf-Jeff/TMC复合膜接触角更小,亲水性能更好,具有一定的抗污染性能,通量恢复率达到91.4％.%In order to improve the antifouling property of forward osmosis membrane, O'O-bis(2-aminopropyl) polypropy-lene glycol-block-polyethylene glycol-block-polypropylene glycol and trimesoyl chloride(TMC) were utilized as the reactant of aqueous monomer and oil phase monomer respectively to fabricate the hydrophilic PEO polyamide forward osmosis membrane (PSf-Jeff/TMC composite membrane) through the interfacial polymerization on the polysulfone support membrane. The chemical structure and hydrophilic performance of PEO-functionalized se-lective layer were evaluated by total reflection Fourier transform infrared spectroscopy (FTIR-ATR), X-ray photoelectron spectroscopy (XPS) and water contact angle technique. The effects of preparation parameters in-cluding polymerization time, concentration of the reactive monomer, and heat-treatment temperature on the per-meation and separation performance of the forward osmosis membrane were investigated and the antifouling per-formance of the forward osmosis membrane was analyzed by using BSA as pollutant. The results show that the op-timum preparation conditions are as follows: the reaction time is 30 s, the concentration of aqueous phase monomer is 3％(mass fraction), the mass concentration of TMC is 1.5 mg/mL, and the curing temperature is 60℃. The PSf-Jeff/TMC composite membrane has a pure water flux of 1.75 L/(m2·h)and reverse salt flux of 140 g/(m2·h)under the condition of 1 mol/L NaCl at the room temperature. The PSf-Jeff/TMC composite membrane has better hydrophilicity with a lower water contact angle,and an excellent antifouling property with pure water flux recovery of 91.4％compared with PSf-MPD/TMC composite membrane.