Vapor Phase Infiltration of Metal Oxides into Nanoporous Polymers for Organic Solvent Separation Membranes
Vapor Phase Infiltration of Metal Oxides into Nanoporous Polymers for Organic Solvent Separation Membranes
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DOI：
10.1021/acs.chemmater.9b01141
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发表时间：
2019-08-13
影响因子：
8.6
通讯作者：
Losego, Mark D.
中科院分区：
文献类型：
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作者：
McGuinness, Emily K.;Zhang, Fengyi;Losego, Mark D.
基于膜的有机溶剂分离有望成为传统热分离的低能耗替代方案，但需要在化学腐蚀性环境中可靠运行的材料。虽然无机膜可以承受苛刻的条件，但它们昂贵且难以规模化。聚合物膜，例如固有微孔聚合物1（PIM-1），容易制造成与大规模分离一致的形式（例如，中空纤维），但在腐蚀性溶剂中表现不佳。在这里，一种新的制造后膜改性技术，气相渗透（VPI），据报道，注入PIM-1与无机成分，以提高稳定性，同时保持聚合物的宏观形式和纳米多孔的内部结构。这些混合膜内的原子级金属氧化物网络保护PIM-1免于溶胀或溶解在溶剂中。这种稳定性转化为在各种溶剂（包括能够溶解PIM-1的溶剂）中改进的分离性能。渗透的无机相也出现了新的控制溶质吸附在有机溶剂纳滤（OSN）。这些杂化膜进一步显示出有前途的性能，在具有挑战性的溶剂中的有机溶剂反渗透（OSRO）分离，即使在小分子量差异（14 Da）。由于VPI工艺可以与最先进的膜组件集成，因此这种处理可以很容易地用于先进膜的大规模制造。
Membrane-based organic solvent separations promise a low-energy alternative to traditional thermal separations but require materials that operate reliably in chemically aggressive environments. While inorganic membranes can withstand demanding conditions, they are costly and difficult to scale. Polymeric membranes, such as polymer of intrinsic microporosity 1 (PIM-1), are easily manufactured into forms consistent with large-scale separations (e.g., hollow fibers) but perform poorly in aggressive solvents. Here, a new postfabrication membrane modification technique, vapor phase infiltration (VPI), is reported that infuses PIM-1 with inorganic constituents to improve stability while maintaining the polymer's macroscale form and nanoporous internal structure. The atomic-scale metal oxide networks within these hybrid membranes protect PIM-1 from swelling or dissolving in solvents. This stability translates to improved separation performance in a variety of solvents, including solvents capable of dissolving PIM-1. The infiltrated inorganic phase also appears to give new control over solute sorption in organic solvent nanofiltration (OSN). These hybrid membranes further show promising performance for organic solvent reverse osmosis (OSRO) separations in challenging solvents, even at small-molecular-weight differentials (14 Da). Because the VPI process can be integrated with state-of-the-art membrane modules, this treatment could be readily adopted into the large-scale manufacturing of advanced membranes.