Electrospun stereocomplex polylactide porous fibers toward highly efficient oil/water separation

The urgent needs for water protection are not only developing the highly efficient wastewater treatment technologies but also designing the eco-friendly materials. In this work, the eco-friendly composite fibers composed of poly(L-lactide) (PLLA), poly(D-lactide) (PDLA) and maghemite nanoparticles γ-Fe₂O₃ nanoparticles were fabricated through electrospinning technology. Through regulating the processing parameters and introducing additional annealing treatment, nanoscale porous structure and the stereocomplex crystallites (SCs) are simultaneously constructed in the composite electrospun fibers. Physicochemical performances measurements exhibited that the fiber membranes had excellent lipophilicity, good mechanical performances, and high hydrolysis resistance, and all of which endowed the fiber membranes with high oil adsorption capacities, and the maximum oil adsorption capacities achieved 148.9 g/g at 23 °C and 114.8 g/g at 60 °C. Further results showed that the fiber membranes had good oil/water separation ability. The gravity-driven oil flux was 6824.4 L/m²h², and the water rejection ratio was nearly 100% during separating oil/water mixture. Specifically, the fiber membranes showed good stability during the cycling measurements. It is evidently confirmed that the composite PLLA-based fiber membranes with porous structure and SCs can be used in wastewater treatment, especially in some rigorous circumstances.