Abstract:
Surface patterning is a promising strategy to overcome the trade-off effect of separation membranes. Herein, a bottom-up patterning strategy of locking micron-sized carbon nanotube cages (CNCs) onto a nanofibrous substrate is developed. The strongly enhanced capillary force triggered by the abundant narrow channels in CNCs endows the precisely patterned substrate with excellent wettability and antigravity water transport. Both are crucial for the preloading of cucurbit[n]uril (CB6)-embeded amine solution to form an ultrathin (∼20 nm) polyamide selective layer clinging to CNCs-patterned substrate. The CNCs-patterning and CB6 modification result in a 40.2% increased transmission area, a reduced thickness, and a lowered cross-linking degree of selective layer, leading to a high water permeability of 124.9 L·m-2 h-1 bar-1 and a rejection of 99.9% for Janus Green B (511.07 Da), an order of magnitude higher than that of commercial membranes. The new patterning strategy provides technical and theoretical guidance for designing next-generation dye/salt separation membranes.
摘要:
表面图案化是克服分离膜的权衡效应的有前途的策略。在这里,开发了将微米尺寸的碳纳米管笼(CNCs)锁定到纳米纤维衬底上的自下而上的图案化策略。由CNCs中丰富的窄通道触发的强烈增强的毛细管力赋予精确图案化的基底以优异的润湿性和反重力水传输。两者都是至关重要的预载葫芦[n]脲(CB6)-嵌入胺溶液形成超薄(~20nm)聚酰胺选择性层附着在CNCs图案化基材上。CNCs图案化和CB6修饰导致透射面积增加40.2%,厚度减小,和降低交联度的选择性层,导致124.9L·m-2h-1bar-1的高透水性和对JanusGreenB(511.07Da)的99.9%的截留率,比商业膜高一个数量级。新的图案化策略为设计下一代染料/盐分离膜提供了技术和理论指导。