Sulfonated Zr-Based Metal-Organic Framework Incorporated Thin-Film Composite Membrane for Enhanced Desalination

Desalination through reverse osmosis (RO) membrane is one of the most popular way. However, conventional RO membranes meet a trade-off between salt rejection and water flux which limit their comprehensive performance. In this work, Sulfonated Zirconium (IV)- carboxylate metal-organic framework (MOF) material UiO-66-SO3H was successfully synthesized, and thin film nanocomposite (TFN) with UiO-66-X (-H/-NH2/-SO3H) incorporated polyamide (PA) layer were fabricated. Angstrom-sized UiO-66-X ion transport channels with different functional groups in TFN membranes change the membrane morphology and chemistry, accelerate the penetration of water molecules while maintaining the high ion screening effect. As a result, comparing to the pristine TFC membrane, the optimized TFN-UiO-66-SO3H membrane shows an increase of water molecules permeability to 347% and still maintained a salt rejection with ~94.7% under 2000 ppm NaCl solution with reverse osmosis (RO) mode, leading to a great improvement of intrinsic separation properties. The improved performance was owing to the size exclusion effect and hydrophilic nature of UiO-66-SO3H particles. What's more, the additional water migration channels through the incorporated UiO-66-SO3H nanoparticles lead to a boosting water permeation. To our best knowledge, it is the first time to make investigation in sulfonated UiO-66-SO3H incorporated TFN membrane for desalination.