Preparation and characterization of poly (N-vinyl imidazole) gel-filled nanofiltration membranes
Preparation and characterization of poly (N-vinyl imidazole) gel-filled nanofiltration membranes
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聚(N-乙烯基咪唑)凝胶填充纳滤膜的制备及表征
DOI：
10.1016/j.memsci.2015.04.033
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发表时间：
2015-10-15
影响因子：
9.5
通讯作者：
Xu, You-Yi
中科院分区：
文献类型：
--
作者：
Cheng, Liang;Zhang, Pei-Bin;Xu, You-Yi
以N-乙烯基咪唑（VI）为单体，在聚砜（PSI）超滤（UF）底物上和不带交联剂N，N′-亚甲基双丙烯酰胺（MBAA），通过uv引发接枝聚合合成了聚（N-乙烯基咪唑）（PVI）凝胶填充纳滤（NE）膜。从表面化学成分（ATR-FTIR， XPS）、表面形貌（SEM）、表面电荷（zeta电位）、表面润湿性（水接触角）和屏障性能（透水性、中性溶质/离子排斥和膜稳定性）等方面对复合膜进行了全面表征。根据中性溶质（包括维生素B-12和peg）的排斥数据，进一步确定了膜的平均孔径和孔径分布。这些结果证实了制备的膜是稳定、无缺陷、光滑、亲水的NE膜，有效孔径在1.5 ~ 2 nm之间，水渗透率在0.5 ~ 10 L m(-2) h(-1) bar（-1）之间，并且由于掺入的PVI凝胶的弱多碱特性，膜在中性或微酸性溶液中会携带轻微的正电荷。在接近中性的条件下（pH 5.9 +/- 0.3），小孔径膜表现出较高的盐拒绝率，其大小为MgCl2 > NaCl，近似于MgSO4 > NaSO4。这证明了它们基于尺寸排斥的NE分离能力，由Donnan斥力促进。最后，通过与另一种具有微孔基质的凝胶填充NE膜的比较，并通过应用凝胶模型，我们对控制这种凝胶填充膜性能的潜在基本参数进行了定性描述。总的来说，这些新型的弱聚基凝胶填充NF膜具有理想的纳米孔径和潜在可调的电荷特性，可以为分子级分离提供很大的通用性。(C) 2015 Elsevier B.V.版权所有
Poly (N-vinyl imidazole) (PVI) gel filled nanofiltration (NE) membranes were synthesized by UV-initiated graft polymerization of N-vinyl imidazole (VI) monomer, with and without crosslinker N,N'-methylenbisacrylamide (MBAA) on/in a polysulfone (PSI) ultrafiltration (UF) substrate. A comprehensive characterization of the resulting composite membranes was conducted in terms of surface chemical composition (ATR-FTIR, XPS), surface morphology (SEM), surface charge (zeta potential), surface wettability (water contact angle) and barrier properties (water permeance, neutral solute/ions rejection and membrane stability). From rejection data of neutral solutes, including Vitamin B-12 and PEGs, the average pore sizes and pore size distributions of membranes were further determined. These results confirmed the prepared membranes as stable, defect-free, smooth, hydrophilic NE membranes with effective pore size between similar to 1.5 and 2 nm and water permeance between similar to 0.5 and 10 L m(-2) h(-1) bar(-1), Moreover, owing to the weak polybase characteristic of the incorporated PVI gel, the membranes would carry slight positive charge in neutral or slightly acidic solution. The small pore size membranes displayed high salt rejections in the order of MgCl2 > NaCl approximate to MgSO4 > NaSO4 at near-neutral condition (pH 5.9 +/- 0.3). This testified their NE separation capability based on size exclusion, facilitated by Donnan repulsion. At last, by comparison with another reported type of gel-filled NE membranes with microporous substrate, and by applying a gel model, we delivered a qualitative description of the underlying fundamental parameters controlling the performance of such gel-filled membranes. Overall, these novel weak polybase gel-filled NF membranes with desirable nanometerssize pores and potentially tunable charge characteristics could offer great versatility for molecular-level separations. (C) 2015 Elsevier B.V. All rights reserved.