Effective fractionation of ions does not only play a vital role in the functioning of human cell membranes, but also in engineered membranes used to produce drinkable water, extract target minerals and capture energy to address challenges in environmental, resource & energy fields. Nevertheless, most of the state-of-the-art membranes fail to overcome the trade-off between single ion selectivity and throughput. The progress is greatly hampered by the lack of comprehensive understanding on the separation mechanisms across different types of as-claimed ion selective membranes. The IonFracMem project will make breakthroughs by designing novel facilitated ion exchange membranes using an interdisciplinary approach based on electrochemistry, which synergizes with the interaction between target ion and functional materials to form ion selective sites in the membrane and thus facilitate its transport. To achieve a holistic understanding, we will purposely construct two types of membranes with completely different structure for fractionating ions: 1) polymeric membranes of flexible nature, made of conventional or hydrogel polymers (Obj. 1); 2) composite membrane of rigid nature, consisting of nanomaterials with sub-nanometer cavities (Obj. 2). Subsequently, we will provide mechanistic understanding of the facilitated transport phenomena via a multi-scale modelling approach (Obj. 3), to identify governing mechanisms that can be translated to membrane fabrication parameters. The project integrates several key engineering & science disciplines such as separation technology, material processing and functionalization, electrochemistry and fundamental physics, allowing rational design of next generation membranes from a wide range of materials for ion purification. The proposed multidisciplinary approach will impact theories and applications of electro-driven membranes in important domains such as water purification, resource recovery &
sustainable energy.
