Robust Covalently Cross-linked Polybenzimidazole/Graphene Oxide Membranes for High-Flux Organic Solvent Nanofiltration
Robust Covalently Cross-linked Polybenzimidazole/Graphene Oxide Membranes for High-Flux Organic Solvent Nanofiltration
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DOI：
10.1021/acsami.8b03591
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发表时间：
2018-05-09
影响因子：
9.5
通讯作者：
Blanford, Christopher F.
中科院分区：
文献类型：
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作者：
Fei, Fan;Cseri, Levente;Blanford, Christopher F.
开发了用于有机溶剂纳滤的坚固的、易于扩展的、高通量的氧化石墨烯（GO）混合基质复合膜。以4-氯甲基苯甲醇和聚苯并咪唑为原料，通过N-苄基化反应合成了羟基聚苯并咪唑。通过常规的刮刀涂布和相转化制备包含聚苯并咪唑和1或2wt% GO的平板复合膜。随后，使用二异氰酸酯交联剂将GO共价锚定到聚合物的羟基。通过可见光显微镜绘制GO在膜中的均匀分布。羟基化和GO在聚合物基质中的掺入使丙酮中的渗透性增加至45.2 +/- 1.6 L m（-2）h（-1）bar（-1），比未改性的基准膜高近5倍。从添加GO的渗透性的增强没有妥协的溶质排斥。复合膜被发现是紧密的，在7种有机溶剂中，具有低至140克摩尔（-1）的分子量截止（MWCO）。渗透性随着溶剂极性的增加而增加，而对420 g mol（-1）药物的截留率仍超过93%。共价锚定导致稳健的复合膜，其在连续错流配置中在14天内保持恒定的性能。
Robust, readily scalable, high-flux graphene oxide (GO) mixed matrix composite membranes were developed for organic solvent nanofiltration. Hydroxylated polybenzimidazole was synthesized by N-benzylation of polybenzimidazole with 4-(chloromethyl)benzyl alcohol, which was confirmed by FTIR and NMR spectroscopy. Flat-sheet composite membranes comprising of polybenzimidazoles and 1 or 2 wt % GO were fabricated via conventional blade coating and phase inversion. Subsequently, GO was covalently anchored to the hydroxyl groups of the polymer using a diisocyanate cross-linking agent. The even distribution of GO in the membranes was mapped by visible-light microscopy. Hydroxylation and incorporation of GO in the polymer matrix increased the permeance up to 45.2 +/- 1.6 L m(-2) h(-1) bar(-1) in acetone, nearly 5 times higher than the unmodified benchmark membrane. The enhancement in permeance from the addition of GO did not compromise the solute rejection. The composite membranes were found to be tight in seven organic solvents, having molecular weight cut-offs (MWCO) as low as 140 g mol(-1). Permeance increased with increasing solvent polarity, while rejection of a 420 g mol(-1) pharmaceutical remained over 93%. The covalent anchoring resulted in robust composite membranes that maintained constant performance over 14 days in a continuous cross-flow configuration.