基于亚纳米孔道微调制备用于高效分子筛分的超薄耐酸膜

Unprecedented acid-tolerant ultrathin membranes with finely tuned sub-nanopores for energetic-efficient molecular sieving

分离膜被广泛应用于分子分离等领域,但由于膜本身通量与筛分性能之间此消彼长的“trade-off”效应,传统分离膜的效率受到极大限制.本文报道了以多酚作为限速的亲核试剂,与二异氰酸酯进行界面缩合,制备得到了孔径均匀且选择层厚度仅为10 nm的超薄聚氨酯复合膜,并通过实验和密度泛函理论(DFT)模拟计算进行了验证.制备的新型聚氨酯复合纳滤膜在通量提高的同时显著增强了对各种染料和重金属离子的筛分性能,成功突破了传统聚合物分离膜的“trade-off”瓶颈问题.此外合成聚氨酯复合膜的高度交联结构使其能够在强酸条件下稳定运行500 h以上,在环境修复和资源回收利用等领域具有巨大的应用潜力.

The discharge of acidic effluent streams containing multivalent metal ions and toxic dyes from industry poses an ineluctable threat to aquatic ecosystems and public health.Nanofiltration(NF,pore size ranging from 0.5 to 2 nm),featured by the efficient,environmentally friendly and continuous purification way,have been considered as an ideal technology to dispose acidic wastewater[1],[2].However,most polymer membranes suffer from structural instability in acidic media[3].Consequently,the potential huge markets owing to demanding but rather underdeveloped acid-resistant NF membranes have promoted the urgently intensive research based on material and synthesis innovations.