Thin film composite (TFC) polymer membranes are ubiquitous in membrane-based liquid separation processes, especially in reverse osmosis (RO). While the ultrathin polyamide separating layer employed in TFC membranes has exhibited excellent performance in many liquid separation processes, the polymer support has been identified as a bottleneck to practical applications. In this work, we report a highly porous, thermally and chemically robust support comprising a thermally rearranged polymer which is combined with a polyamide active layer to form a thermally rearranged, thin film composite (TR-TFC) polymer membrane for general use in liquid separation, and for environmentally-friendly power generation. The precursor polymer has good processability for scale-up of synthesis and membrane fabrication. After thermal rearrangement, the developed TR-TFC membranes containing polybenzoxazole-co-imide can be utilized in separations in any organic liquids, including under harsh environments such as dimethyl formamide even at elevated temperatures, with a remarkable performance. Moreover, the membrane achieves 40 W m⁻² of power density through pressure retarded osmosis using a concentrated brine, similar to those obtained from RO plants. These results points to the possibilities for next-generation TFC polymer membranes for general use in liquid separation and power generation.

薄膜复合（TFC）聚合物膜在基于膜的液体分离过程中无处不在，尤其是在反渗透（RO）中。尽管TFC膜中使用的超薄聚酰胺分离层在许多液体分离过程中均表现出出色的性能，但聚合物载体已被认为是实际应用的瓶颈。在这项工作中，我们报告了一种高度多孔，热化学稳定性强的载体，其中包含热重排的聚合物，该载体与聚酰胺活性层结合形成了热重排的薄膜复合材料（TR-TFC）聚合物膜，通常用于液体分离，并用于环保型发电。前体聚合物具有良好的可加工性，可用于规模化合成和膜制造。热重排后共酰亚胺可用于任何有机液体的分离，包括在苛刻的环境下，例如二甲基甲酰胺，即使在高温下，也具有出色的性能。而且，该膜通过使用浓盐水的压力渗透渗透而实现了40 W m ^-2的功率密度，这与从反渗透装置获得的类似。这些结果指出了用于液体分离和发电的下一代TFC聚合物膜的可能性。