Water-Stable Metal–Organic Framework UiO-66 for Performance Enhancement of Forward Osmosis Membranes

Abstract

Forward osmosis (FO) is an emerging technology for environmental applications such as seawater desalination and wastewater treatment. However, the lack of long-term water stability and internal concentration polarization (ICP) phenomenon of FO membranes are the key challenges limiting its impact in real practice. In this study, we explore the use of water-stable metal−organic framework UiO-66 in different concentrations as fillers for the fabrication of high-performance and water-stable FO mixed-matrix membranes (MMMs) with mitigated ICP. The influences of UiO-66 on the phase inversion pathway and postinterfacial polymerization reaction cause changes in membrane morphology and chemistry, reducing the membrane structural parameter (S) and mitigating the ICP effect. As a result, the best performing FO membrane (6.5 wt % UiO-66) exhibits a 50% increased water flux over the pristine membrane, when deionized water and 1 M NaCl are used as the feed and draw solutions, respectively. The extent of ICP mitigation has been quantified by the solution-diffusion model, demonstrating effective control by the presence of UiO-66. Because of the excellent water stability of UiO-66, no significant degradation of water permeability is observed over 72 h operation. Therefore, the newly designed UiO-66 incorporated FO MMMs are of great interest and have potential for advancing membrane performances in water filtration and related environmental practice.

Carbon Dioxide Capture Enhanced by Pre‐Adsorption of Water and Methanol in UiO‐66

“…[ 9 , 10 ] There are several known MOFs that are water stable, such as MIL‐100,[ 11 , 12 , 13 ] MIL‐101[ 14 , 15 ] or MIL‐53[ 16 , 17 ] but the flagship in terms of water adsorption, zirconium‐based UiO‐66, stands out. [ 18 , 19 , 20 , 21 , 22 ] Moreover, several studies have been conducted on the co‐adsorption of water and carbon dioxide in MOF materials,[ 23 , 24 , 25 , 26 ] where the pre‐adsorbed water increased the carbon dioxide adsorption capacity. Most previous works explained this fact by additional Coulomb interactions between carbon dioxide and water molecules.…”

Research on Forward Osmosis Membrane Technology Still Needs Improvement in Water Recovery and Wastewater Treatment

“…You S et al [26,35] developed a new kind of thin-film inorganic membrane made of microporous silica xerogels immobilized onto a stainless steel mesh (SSM) substrate, reaching an average rejection efficiency of 94% for heavy metals. Water-stable metal-organic framework UiO-66 was explored to fabricate high-performance mixed-matrix membranes which exhibited a 50% increased water flux over the commercial membrane [36]. Nanocellulose was decorated silver and platinum nanoparticles as additive materials to fabricate the support layer of thin film composite (TFC) membranes for water purification applications [37].…”

Search for optimal monomers for fabricating active layers in thin-film composite osmosis membranes by conceptual density functional theory

“…TFC membranes usually have a double-layer (i.e., the active and support layers) structure that is ideal for water purification and pollutant rejection. The typical synthetic material for the support layer is polysulfone, which provides great mechanical strength and antipollution performance [3].…”