MOLECULAR CAGE COMPOUNDS AS SYNTHETIC WATER CHANNELS

Abstract

Natural water channels such as aquaporins that selectively transport water have inspired the design of more robust synthetic water channels. However, these channels are generally one-dimensional, making the transport performance highly dependent on their orientation. To circumvent the problem, this thesis explores a family of zero-dimensional, porous molecular cages as orientation-independent synthetic water channels. The molecular cages were first theoretically demonstrated on a biomimetic platform to transport water at the same magnitude as aquaporins while fully rejecting ions. Their structural-performance relationship was also studied experimentally and computationally. Following, the molecular cages were introduced into the reverse osmosis polyamide thin-film nanocomposite (TFN) membrane as nanofillers. They were observed to distribute homogeneously throughout the polymeric membrane at a near molecular state, and enhanced the membrane water permeability by ca. 3.5-fold without compromising the salt rejection. The molecular cages also exhibited added benefits such as excellent antifouling properties.