Polydopamine-assisted MXene decoration on electrospun polylactide fibers toward oil/water separation and organic dye adsorption

As an eco-friendly material, the wide application of polylactide (PLA) in wastewater treatment is favorable for eliminating the possible second-pollution induced by the common membrane materials. However, the application of PLA is also greatly restricted by the hydrophobicity and inert surface of PLA-based materials. In this work, the electrospun PLA fiber film with stereocomplex crystallites (SC-PLA) was prepared through electrospinning, then the successive decorations of self-polymerization of polydopamine (PDA) and PDA-assisted MXene deposition were carried out. The physicochemical performances such as wettability, mechanical properties, and photothermal conversion ability were intensively researched. Then, the oil/water separation ability and the organic pollutants removal effect of the composite membranes were systematically researched. The results show that the composite membrane is amphiphilic, which results in the membrane exhibiting high fluxes and excellent oil/water separation performance in the separation process of different types of emulsions, and oil/water separation efficiency can be further enhanced under light irradiation. Specifically, the maximum adsorption capacity of the composite membrane for methylene blue (MB) reached 434.8 mg/g, and the composite membrane can also simultaneously remove oil and MB from the emulsified solution in the one-time separation process. This work demonstrates that the PLA-based composite membranes have potential application in sewage purification and can be the alternative for the next generation membrane separation material.