Deployment of Superhydrophilic and Super-antifouling Cr-soc-MOF-1-Based Membrane for Ultrafast Separation of Stabilized Oil-in-Water Emulsions

In spite of massive progress in oil-water separation,attributableto the use of advanced materials, the separation process faces challengessuch as low permeance and fouling problems. Therefore, superwettablematerials used in several fields are considered potential candidatesfor oily wastewater treatment. Metal-organic frameworks (MOFs)are receiving more and more interest in various separation applicationsdue to their wide potential applications. Nevertheless, MOFs havebeen rarely explored for separating stabilized oil-in-water emulsionsdue to the difficulty in finding highly hydrolytic stable MOF candidatesfor this application. Furthermore, oil can clog water-stable materialsowing to its high density, causing the degradation of MOF particles.As a result, there is a need to develop better MOF materials thatcan fulfill these requirements. Herein, we have explored Cr-soc-MOF-1 as a candidate for this application and deployedit as a membrane, which exhibited superhydrophilicity and underwatersuperoleophobicity for separating stabilized oil-in-water emulsions.The Cr-soc-MOF-1 membranes were synthesized by assemblingthe as-prepared MOF particles on a mixed cellulose ester substrateusing a vacuum-assisted self-assembly technique. The Cr-soc-MOF-1 membrane exhibited ultrahigh water permeance (7465.9 L center dot m(-2)center dot h(-1)center dot bar(-1)), very high oil rejection (99.9%), and excellent anti-oil-foulingproperties. The Cr-soc-MOF-1 membranes also exhibitedexcellent recyclability over 10 continuous separation cycles. Further,they exhibited an outstanding performance in separating various surfactant-stabilizedoil-in-water emulsions. Thus, the Cr-soc-MOF-1 membranesexhibit a high potential in treating oily wastewater.

Automated summary

Despite progress in oil-water separation, challenges like low permeance and fouling problems still exist. Superwettable materials, particularly metal-organic frameworks (MOFs), are potential candidates for oily wastewater treatment. However, MOFs have been rarely explored for separating stabilized oil-in-water emulsions, calling for the development of better MOF materials.