Moon Seung Jae, Kim Young Jun, Kang Du Ru, Lee So Youn, Kim Jong Hak
Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul 03722, Republic of Korea.
Polymers (Basel). 2023 Sep 1;15(17):3623. doi: 10.3390/polym15173623.
Neat poly(vinylidene fluoride) (PVDF) ultrafiltration (UF) membranes exhibit poor water permeance and surface hydrophobicity, resulting in poor antifouling properties. Herein, we report the synthesis of a fluorine-containing amphiphilic graft copolymer, poly(2,2,2-trifluoroethyl methacrylate)--poly(ethylene glycol) behenyl ether methacrylate (PTFEMA--PEGBEM), hereafter referred to as PTF, and its effect on the structure, morphology, and properties of PVDF membranes. The PTF graft copolymer formed a self-assembled nanostructure with a size of 7-8 nm, benefiting from its amphiphilic nature and microphase separation ability. During the nonsolvent-induced phase separation (NIPS) process, the hydrophilic PEGBEM chains were preferentially oriented towards the membrane surface, whereas the superhydrophobic PTFEMA chains were confined in the hydrophobic PVDF matrix. The PTF graft copolymer not only increased the pore size and porosity but also significantly improved the surface hydrophilicity, flux recovery ratio (FRR), and antifouling properties of the membrane. The membrane performance was optimal at 5 wt.% PTF loading, with a water permeance of 45 L m h bar, a BSA rejection of 98.6%, and an FRR of 83.0%, which were much greater than those of the neat PVDF membrane. Notably, the tensile strength of the membrane reached 6.34 MPa, which indicated much better mechanical properties than those reported in the literature. These results highlight the effectiveness of surface modification via the rational design of polymer additives and the precise adjustment of the components for preparing membranes with high performance and excellent mechanical properties.
纯聚偏氟乙烯（PVDF）超滤（UF）膜表现出较差的水渗透性和表面疏水性，导致其抗污染性能不佳。在此，我们报道了一种含氟两亲性接枝共聚物聚（甲基丙烯酸2,2,2 - 三氟乙酯）-聚（乙二醇山嵛醚甲基丙烯酸酯）（PTFEMA-PEGBEM），以下简称PTF的合成及其对PVDF膜结构、形态和性能的影响。PTF接枝共聚物由于其两亲性本质和微相分离能力形成了尺寸为7 - 8 nm的自组装纳米结构。在非溶剂诱导相分离（NIPS）过程中，亲水性的PEGBEM链优先取向于膜表面，而超疏水性的PTFEMA链则被限制在疏水性的PVDF基质中。PTF接枝共聚物不仅增加了膜的孔径和孔隙率，还显著提高了膜的表面亲水性、通量恢复率（FRR）和抗污染性能。当PTF负载量为5 wt.%时，膜性能最佳，水通量为45 L m⁻² h⁻¹ bar⁻¹，牛血清白蛋白截留率为98.6%，FRR为83.0%，均远高于纯PVDF膜。值得注意的是，膜的拉伸强度达到6.34 MPa，表明其机械性能比文献报道的要好得多。这些结果突出了通过合理设计聚合物添加剂和精确调整组分来进行表面改性以制备具有高性能和优异机械性能的膜的有效性。
