Thin-film composite (TFC) membranes are favored for precise molecular sieving in liquid-phase separations; they possess high permeability due to the minimal thickness of the active layer and the high porosity of the support layer. However, current TFC membrane fabrication techniques are limited by the available materials for the selective layer and do not demonstrate the level of structural control needed to substantially advance organic solvent nanofiltration (OSN) membrane technology. In this work, we employ the newly developed thin-film lift-off (T-FLO) technique to fabricate polybenzimidazole (PBI) TFC membranes with porous support layers uniquely tailored to OSN. The drop-cast dense PBI selective layers endow the membranes with an almost complete rejection of common small dye molecules. The polymeric support layer is optimized by a combinatorial approach using four different monomers that alter the cross-linking density and polymer chain flexibility of the final composite. These two properties substantially affect the porogen holding capacity of the reticular polymer network, leading to the formation of different macropore structures. With a 150 nm thick PBI selective layer and fine-tuning of the support layer, the resulting membrane achieves stable and superior permeance of 14.0, 11.7, 16.4, 11.4, 17.1, and 19.7 L m^–2 h^–1 bar^–1 for water, ethanol, methanol, isopropanol, tetrahydrofuran (THF), and acetonitrile, respectively.

中文翻译：

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超透性有机溶剂纳米过滤膜，具有使用薄膜剥离技术制造的精确定制的支撑层。

薄膜复合（TFC）膜特别适合在液相分离中进行精确的分子筛。由于活性层的最小厚度和支撑层的高孔隙率，它们具有高渗透性。但是，当前的TFC膜制造技术受到用于选择层的可用材料的限制，并且没有显示出实质上促进有机溶剂纳米过滤（OSN）膜技术所需的结构控制水平。在这项工作中，我们采用了最新开发的薄膜剥离（T-FLO）技术来制造具有专门针对OSN的多孔支撑层的聚苯并咪唑（PBI）TFC膜。滴铸致密的PBI选择性层使膜几乎完全排斥常见的小染料分子。通过组合方法使用四种不同的单体来优化聚合物支撑层，所述四种不同的单体会改变最终复合材料的交联密度和聚合物链的柔韧性。这两个性质实质上影响网状聚合物网络的成孔剂保持能力，导致形成不同的大孔结构。借助150 nm厚的PBI选择层和支撑层的微调，所得的膜可实现稳定且优异的渗透率，分别为14.0、11.7、16.4、11.4、17.1和19.7 L m^–2 h ^–1 bar ^–1分别用于水，乙醇，甲醇，异丙醇，四氢呋喃（THF）和乙腈。