Covalent organic frameworks embedded in polystyrene membranes for ion sieving

A mixed matrix membrane composed of COF-300 and polystyrene (PS) with controllable thickness and porosity achieves ion sieving performance, which is dependent on the regular pore size and surface functional groups of COF-300. Hence, the selectivity of the COF-300/PS membrane for K+/Li+ and Mg2+/Li+ reached 31.5 and 14.7, respectively.