Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585, Singapore, Singapore.
NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899-6102, USA.
Nat Commun. 2020 Oct 1;11(1):4927. doi: 10.1038/s41467-020-18639-7.
Nature has protein channels (e.g., aquaporins) that preferentially transport water molecules while rejecting even the smallest hydrated ions. Aspirations to create robust synthetic counterparts have led to the development of a few one-dimensional channels. However, replicating the performance of the protein channels in these synthetic water channels remains a challenge. In addition, the dimensionality of the synthetic water channels also imposes engineering difficulties to align them in membranes. Here we show that zero-dimensional porous organic cages (POCs) with nanoscale pores can effectively reject small cations and anions while allowing fast water permeation (ca. 10 water molecules per second) on the same magnitude as that of aquaporins. Water molecules are found to preferentially flow in single-file, branched chains within the POCs. This work widens the choice of water channel morphologies for water desalination applications.
自然界拥有蛋白质通道（例如水通道蛋白），这些通道优先运输水分子，甚至排斥最小的水合离子。人们渴望创造出强大的合成对应物，这导致了一些一维通道的发展。然而，在这些合成水通道中复制蛋白质通道的性能仍然是一个挑战。此外，合成水通道的维度也给它们在膜中的对齐带来了工程上的困难。在这里，我们表明，具有纳米级孔的零维多孔有机笼（POC）可以有效地排斥小的阳离子和阴离子，同时允许快速的水渗透（约每秒 10 个水分子），与水通道蛋白相当。水分子被发现优先在 POC 内的单链、支链中流动。这项工作拓宽了水通道形态在海水淡化应用中的选择。
