Substrate-Independent Cupric Phosphate Nanoflower–Mineralized Superhydrophilic Membranes for Diverse Oil–Water Separation

Abstract

Developing a sustainable and efficient method or material to clean oily wastewater is a pressing need. Herein, a mussel-inspired mineralization strategy is provided to fabricate a high-performance substrate-independent superhydrophilic coating on diverse membranes to separate various types of oily wastewater. A polydopamine (PDA)/poly(ether imide) (PEI) intermediate layer is introduced via a mussel-guided codeposition technique followed by a mineralization process to create a nanoflower-like Cu 3 (PO 4 ) 2 -PDA/PEI coating on a membrane. Because of the nanoflowered structure and strong hydration ability of Cu 3 (PO 4 ) 2 , the mineralized membrane exhibits superhydrophilicity/underwater superoleophobicity and outstanding anti-oil-fouling properties for efficiently separating various immiscible oil−water mixtures and surfactant-stabilized oil-in-water emulsions. Additionally, the mineralized membrane shows high thermal stability and excellent salt tolerance. The exceptional resistance of the mineralized membrane to oil fouling and its high separation capacity and broad applicability give rise to the tremendous potential of the membrane for practical use in the purification of oily wastewater.

Separation and Photodegradation of Dye-Containing Oil/Water Mixtures with a Photothermally Responsive PNIPAm-MXene/PAN-PNIPAm Nanofibrous Hydrogel Membrane

“…Membrane separation technology has been widely used in wastewater purification due to its low consumption, high separation efficiency, and convenient operation features. − However, traditional separation membranes have poor antifouling performance, resulting in oil droplets or organic dyes in wastewater being easily adhered to the surface of the separation membrane, further blocking the pores during the separation process. Special wettability-oriented separation materials, such as superhydrophilic/underwater superoleophobic and superhydrophobic/superoleophilic materials, show great advantages in fouling resistance over traditional separation methods. − In addition, loading photocatalysts on the separation membrane is also an effective method to photodegrade organic dyes and avoid toxic dye contaminants blocking the pores of the separation membrane . Although oil/water separation membranes with a photodegradation ability have been widely studied, achieving simultaneous oil/water separation and photodegradation in one step still faces great challenges .…”