Metal-organic framework glass membrane with interconnected charged channels for selective Li+/Mg2+ separation through diffusion dialysis

Metal-organic framework (MOF) glasses offer promising potential for membrane-based separations due to their excellent processability and structural versatility. However, their inherently disordered pore structures often lead to reduced porosity and limited ion transport performance. Here, we present a controlled unzipping polymer decomposition (CUPD) strategy for fabricating ZIF-62-based glass membrane featuring interconnected and negatively charged transport channels. Polystyrene sulfonic acid (PSS) is introduced as a sacrificial porogen during the melt-quenching process, wherein partial decomposition of its carbon backbone templates the formation of interconnected micropores. Simultaneously, the sulfonate groups stabilized by coordination with Zn sites, imparted negative surface charge to the channels, facilitating the selective ions transport. The optimized membrane fabricated by CUPD strategy achieves a Li + permeation rate of 0.64 mol m −2 h −1 , which is 60-fold higher than that of the pristine ZIF-62 glass membrane. This work provides a novel inspiration for constructing MOF-based membranes with interconnected channels with tunable property for advanced ion separation applications.