Due to its distinct pore structure consisting of micropores and ultramicropores, carbon molecular sieve (CMS) is a promising material for creating membranes. However, the pyrolysis of an asymmetric polymer precursor to produce CMS membranes would compromise its inherent porous structure, resulting in a thick selective layer that might lead to a low flux membrane. Instead, thin composite membranes with selective CMS layers coated on porous substrates can provide a short transport length for enhanced permeability. In this work, a polymer precursor was dip-coated onto porous alumina hollow fibers, followed by pyrolysis to yield composite hollow fiber membranes with a very thin (∼2 μm), selective CMS layer. Using the composite membranes, xylene mixtures were separated by organic solvent reverse osmosis mode, and enhanced flux of the composite membrane (up to 10 times) was obtained compared to other CMS membranes. It is expected that organic liquid mixtures can be separated at a lower cost through membranes than through the conventional thermal process.

中文翻译：

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薄膜复合碳分子筛中空纤维膜分离液体二甲苯异构体


由于其独特的由微孔和超微孔组成的孔隙结构，碳分子筛（CMS）是一种有前途的膜材料。然而，热解不对称聚合物前体来生产 CMS 膜会损害其固有的多孔结构，导致厚的选择性层，可能导致膜通量低。相反，在多孔基材上涂覆选择性 CMS 层的薄复合膜可以提供较短的传输长度，从而增强渗透性。在这项工作中，将聚合物前体浸涂到多孔氧化铝中空纤维上，然后热解以产生具有非常薄（~2μm）的选择性CMS层的复合中空纤维膜。使用该复合膜，通过有机溶剂反渗透模式分离二甲苯混合物，与其他CMS膜相比，复合膜的通量提高了（高达10倍）。预计通过膜可以比通过传统热​​处理以更低的成本分离有机液体混合物。