Tian Huali, Wu Xing, Zhang Kaisong
Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Membranes (Basel). 2021 Jan 30;11(2):96. doi: 10.3390/membranes11020096.
Tight ultrafiltration (TUF) membranes with high performance have attracted more and more attention in the separation of organic molecules. To improve membrane performance, some methods such as interface polymerization have been applied. However, these approaches have complex operation procedures. In this study, a polydopamine (PDA) modified MoS (MoS@PDA) blending polyethersulfone (PES) membrane with smaller pore size and excellent selectivity was fabricated by a simple phase inversion method. The molecular weight cut-off (MWCO) of as-prepared MoS@PDA mixed matrix membranes (MMMs) changes, and the effective separation of dye molecules in MoS@PDA MMMs with different concentrations were obtained. The addition amount of MoS@PDA increased from 0 to 4.5 wt %, resulting in a series of membranes with the MWCO values of 7402.29, 7007.89, 5803.58, 5589.50, 6632.77, and 6664.55 Da. The MWCO of the membrane M3 (3.0 wt %) was the lowest, the pore size was defined as 2.62 nm, and the pure water flux was 42.0 L m h bar. The rejection of Chromotrope 2B (C2B), Reactive Blue 4 (RB4), and Janus Green B (JGB) in aqueous solution with different concentrations of dyes was better than that of unmodified membrane. The separation effect of M3 and M0 on JGB at different pH values was also investigated. The rejection rate of M3 to JGB was higher than M0 at different pH ranges from 3 to 11. The rejection of M3 was 98.17-99.88%. When pH was 11, the rejection of membranes decreased with the extension of separation time. Specifically, at 180 min, the rejection of M0 and M3 dropped to 77.59% and 88.61%, respectively. In addition, the membrane had a very low retention of salt ions, Nacl 1.58%, NaSO 10.52%, MgSO 4.64%, and MgCl 1.55%, reflecting the potential for separating salts and dyes of MoS@PDA/PES MMMs.
具有高性能的紧密超滤（TUF）膜在有机分子分离中越来越受到关注。为了提高膜性能，已应用了一些方法，如界面聚合。然而，这些方法操作程序复杂。在本研究中，通过简单的相转化法制备了一种聚多巴胺（PDA）改性的二硫化钼（MoS@PDA）与聚醚砜（PES）共混的膜，其孔径更小且选择性优异。所制备的MoS@PDA混合基质膜（MMMs）的截留分子量（MWCO）发生变化，并实现了不同浓度的MoS@PDA MMMs对染料分子的有效分离。MoS@PDA的添加量从0增加到4.5 wt%，得到了一系列MWCO值分别为7402.29、7007.89、5803.58、5589.50、6632.77和6664.55 Da的膜。膜M3（3.0 wt%）的MWCO最低，孔径为2.62 nm，纯水通量为42.0 L m h bar。在不同浓度染料的水溶液中，对变色酸2B（C2B）、活性蓝4（RB4）和姬姆萨绿B（JGB）的截留率优于未改性膜。还研究了M3和M0在不同pH值下对JGB的分离效果。在pH值为3至11的不同范围内，M3对JGB的截留率高于M0。M3的截留率为98.17 - 99.88%。当pH值为11时，膜的截留率随分离时间的延长而降低。具体而言，在180分钟时，M0和M3的截留率分别降至77.59%和88.61%。此外，该膜对盐离子的截留率非常低，氯化钠为1.58%，硫酸钠为10.52%，硫酸镁为4.64%，氯化镁为1.55%，这反映了MoS@PDA/PES MMMs分离盐和染料的潜力。
