Tailor-Made Polyamide Membranes for Water Desalination
Edwin P. Chan, Wansuk Chol, Joona Bang, Jong Suk Lee, Jung-Hyun Lee, Joung-Eun Gu
Independent control over the extrinsic and intrinsic properties of the polyamide selective layer is critical when designing water desalination reverse osmosis (RO) membranes with performance characteristics required for water purification applications besides just seawater desalination. Current commercial water desalination membranes fabricated via the well-established interfacial polymerization (IP) approach yields materials that are far from ideal because their extrinsic and intrinsic transport properties are intimately coupled. In this work, tailor-made polyamide-based water desalination membranes based on molecular layer-by-layer (mLbL) assembly are presented. These mLbL-assembled membranes exhibit significant enhancements in performance compared to their IP-assembled counterparts. A maximum water permeance of 1.48 L m-2 h-1 bar-1 with sodium chloride rejection of 98.2 % is achieved, which is over 2.5 times higher in water flux than the IP-assembled counterpart. This study demonstrates that broad applicability of mLbL in fabricating a variety of polyamide-based water desalination membranes that enable nanoscale control of the selective layer thickness and roughness independent of the specific polyamide chemistry.
Advanced Functional Materials
molecular layer-by-layer, polyamide, thin film composite membrane, reverse osmosis, water desalination