Thin-Film Nanocomposite Membranes Containing Water-Stable Zirconium Metal–Organic Cages for Desalination
Guoliang Liu, Xiaomei Zhang, Yi Yuan, Hongye Yuan, Nanxi Li, Yunpan Ying, Shing Bo Peh, Yuxiang Wang, Youdong Cheng, Yahui Cai, Zhonghua Gu, Hong Cai, Dan Zhao
Abstract
The introduction of porous nanofillers into the polyamide selective layer of thin-film composite membranes is a promising strategy towards improved water flux and salt rejection for reverse osmosis membranes. However, the incorporation of filler particles is constrained by the poor compatibility between particle fillers and a polyamide layer. In this study, we report the rationally chosen zirconium metal–organic cages (Zr-MOCs) with ideal stability, solubility, and porosity characteristics as molecular fillers for thin-film nanocomposite (TFN) membranes. In addition, we use monoamino compounds to fine-tune the structure of the polyamide selective layer and the performance of the TFN membranes following the "defective ligand" strategy. The optimized TFN membranes exhibit up to a fourfold increment in water flux without compromising the salt rejection, underlining the promising potential of Zr-MOCs as molecular fillers in TFN membranes.