Abstract：
The precise manipulation of the microstructure (pore size, free volume distribution, and connectivity of the free-volume elements), thickness, and mechanical characteristics of membranes holds paramount significance in facilitating the effective utilization of self-standing membranes. In this contribution, the synthesis of two innovative ester-linked covalent-organic framework (COF) membranes is first reported, which are generated through the selection of plant-derived ellagic acid and quercetin phenolic monomers in conjunction with terephthaloyl chloride as a building block. The optimization of the microstructure of these two COF membranes is systematically achieved through the application of three different interfacial electric field systems: electric neutrality, positive electricity, and negative electricity. It is observed that the positively charged system facilitates a record increase in the rate of membrane formation, resulting in a denser membrane with a uniform pore size and enhanced flexibility. In addition, a correlation is identified wherein an increase in the alkyl chain length of the surfactants leads to a more uniform pore size and a decrease in the molecular weight cutoff of the COF membrane. The resulting COF membrane exhibits an unprecedented combination of high water permeance, superior sieving capability, robust mechanical strength, chemical robustness for promising membrane-based separation science and technology.
摘要：
微观结构的精确操纵(孔径，自由体积分配，和自由体积元素的连通性)，膜的厚度和机械特性对于促进在化学工业中复杂的分子筛分应用中有效利用自立膜具有至关重要的意义。在这一贡献中,我们首先报道了两种创新的酯连接共价有机骨架（COF）膜的合成，通过选择植物衍生的鞣花酸和槲皮素酚类单体以及对苯二甲酰氯作为结构单元而产生。这两种自立的微观结构的优化，通过应用三种不同的界面电场系统，系统地实现了植物衍生的COF膜：电中性（不含表面活性剂），正电(带正电荷的表面活性剂)和负电(带负电荷的表面活性剂)。观察到带正电荷的系统促进了膜形成速率的创纪录增加，与在电中性和负电荷条件下形成的膜相比,产生具有均匀孔径和增强的柔性的更致密的膜。这种改进主要归因于库仑力和表面活性剂在正己烷/水界面处的均匀取向。此外,确定了相关性，其中表面活性剂的烷基链长度的增加导致更均匀的孔径和COF膜的分子量截止值（MWCO）的降低，这归因于疏水性微环境的形成，导致存在较少的水分子。当表面活性剂链长持续增加时,膜孔径增加。所得的COF膜表现出前所未有的高透水性组合，对小分子具有卓越的筛分能力，强大的机械强度，化学稳健性和耐氯性，为有前途的膜分离科学和技术。本文受版权保护。保留所有权利。
