纳米二氧化硅改性聚酰胺复合膜及其抗污染性能

采用经3-氨基丙基三甲氧基硅烷（APTMS）修饰的纳米二氧化硅（SiNPs），对正渗透聚酰胺复合膜（TFC）进行抗污染改性.在静电吸附作用下，APTMS-SiNPs可通过表面涂覆的方式接枝在带负电的TFC表面，以提高膜的亲水性和抗污染效能.改性后，大量纳米材料成功接枝在膜表面，膜表面的接触角降低了54%，而膜电位和表面粗糙度无明显变化.采用海藻酸钠作为代表污染物，对原膜和改性膜的动态污染行为进行探究，通过监测污染阶段的通量变化和膜表面滤饼层含量，发现改性膜在膜污染后期表现出优良的抗污染性能，最终通量衰减降低了28%，膜表面滤饼层含量减少了35%.改性膜的抗污染性能主要归因于APTMS-SiNPs带来的膜表面亲水性的大幅提高.

Research on the modification of thin-film composite membrane by silica nanoparticles and antifouling performance

In this study, we developed a facile strategy to modify a forward osmosis thin-film composite (TFC) membrane via surface grafting of silica nanoparticles (SiNPs), which was functionalized with amine moieties (3-Aminopropyl trimethoxysilane, APTMS). The APTMS functionalized SiNPs were grafted on the negatively charged TFC membrane via electrostatic interactions during a dip-coating process, to enhance membrane hydrophilicity and impart fouling resistance. After modification process, dense nanoparticles were found grafted on membrane surface. Compared to the pristine membrane, contact angle of the modified membranes significantly reduced by 54%, while surface zeta potential and roughness presented negligible changes. For dynamic fouling tests using sodium alginate as a model foulant, flux behavior and fouling layer characterizations revealed that the modified membranes exhibited notably fouling resistance than the pristine membrane during later period, with flux decline remarkably reduced by 28% and deposited foulants decreased by 35%. The antifouling property of the membrane was mainly attributed to substantial hydrophilicity enhancement due to APTMS-SiNPs functionalization.