Beijing Key Laboratory for Green Catalysis and Separation, College of Environmental and Energy Engineering, Beijing University of Technology , Beijing 100124, P. R. China.
College of Chemical Engineering, Beijing University of Chemical Technology , Beijing 100029, P. R. China.
ACS Appl Mater Interfaces. 2017 Dec 27;9(51):44820-44827. doi: 10.1021/acsami.7b14017. Epub 2017 Dec 14.
The key to improving nanofiltration membrane permeance is reducing its thickness while maintaining high rejection. Herein, a 25 nm thick ultrathin polyamide layer was prepared by a microphase diffusion-controlled interfacial polymerization (MDC-IP) of poly(ethyleneimine) and trimesoyl chloride, which is much thinner than the conventional interfacial polymerization (CIP) polyamide layer. A new formation mechanism for such an ultrathin layer is presented, which included a microphase interfacial reaction and eliminated loose layers due to the confinement of microphase diffusion and the termination of stepwise diffusion. Moreover, the polyamide layer was post-cross-linked to form a stable dual-cross-linked interwoven structure. Such a membrane showed an ultrahigh permeance of 1246 kg/(m h MPa), which was 23 times that of CIP membranes. MDC-IP could efficiently control the microinterface between two immiscible phases, which provided a facile way to regulate the membrane at nanoscale.
提高纳滤膜渗透性的关键在于在保持高截留率的同时降低其厚度。本文通过聚（亚乙基亚胺）和均苯三甲酰氯的微相扩散控制界面聚合（MDC-IP）制备了 25nm 厚的超薄聚酰胺层，其厚度远小于传统界面聚合（CIP）聚酰胺层。提出了一种形成这种超薄层的新机制，该机制包括微相间的界面反应，并通过微相扩散的限制和逐步扩散的终止消除了疏松层。此外，对聚酰胺层进行后交联，形成稳定的双交联交织结构。这种膜的渗透通量高达 1246kg/（m h MPa），是 CIP 膜的 23 倍。MDC-IP 可以有效地控制两个不混溶相之间的微界面，为在纳米尺度上调控膜提供了一种简单的方法。
