Tuning Ion Transport in 2D Phyllosilicate Membranes

Membranes incorporating two-dimensional (2D) materials have shown great potential for water purification and energy storage and conversion applications to overcome the challenges of traditional polymetric membranes. A variety of 2D materials such as graphene oxide, transitional metal dichalcogenides, and MXenes have been investigated for membrane applications. Phyllosilicate minerals are naturally occurring layered materials that are earth-abundant and low-cost. These materials are composed of negatively charged 2D aluminosilicate layers and interlayer cations, which can be easily exfoliated by replacing the cations and subsequently restacked as 2D laminar membranes. However, as formed, these membranes exhibit poor water stability and limited ion transport selectivity. The transport properties of phyllosilicate membranes are determined by the chemical and structural properties of the 2D interlayer galleries. We report systematic approaches to tuning the ion transport properties of phyllosilicate membranes through molecular crosslinking and surface functionalization. The channel height of the 2D interlayer gallery can be tuned by controlling the crosslinker size, leading to enhanced stability and tunable water and ion transport [1]. Furthermore, the chemical environment of the 2D interlayer can be altered through surface functionalization, resulting in boosted ion transport selectivity. The prepared phyllosilicate membranes with enhanced water stability and tunable ion transport properties have great potential in separation applications such as water purification and resource recovery [2].<br/>[1] Y. Liu et al., <i>ACS Appl. Mater. Interfaces </i><b>15</b> (2023) 57144<br/>[2] O. Kazi et al., <i>Adv. Mater.</i> <b>35</b> (2023) 2300913