Bio-degradable fibrous membranes for oil/water separation by melt electrospinning

Various electrospun fibrous membranes have been addressed for oil/water separation owing to their advantages of high specific surface ratio, lightweight, and high porosity. However, they are commonly obtained by solution electrospinning of non-green raw materials, which could cause serious environmental issues. To realize effective oil/water separation, the optimal processing parameters for melt electrospun polylactic acid (PLA) were determined through orthogonal experiments. Subsequently, PLA fibrous films with cellulose nanofiber (CNF) or sodium chloride (NaCl) for oil/water separation were produced via melt electrospinning. The effects of incorporating CNF or NaCl on the physiochemical properties of melt electrospun PLA fibrous membranes were investigated. In contrast to the pure PLA membranes, the obtained PLA/CNF and PLA/NaCl composite membranes exhibit a finer average fiber diameter and an increased porosity. Also, the oil absorption characteristics and oil/water separation abilities of these fibrous membranes were experimentally studied. In contrast to the 84.55% oil/water separation efficiency of melt-electrospun PLA fibrous membranes, PLA/CNF exhibits the highest oil/water separation efficiency at 93.54%, whereas PLA/NaCl achieves a maximum efficiency of 90.29%. These findings show the applicability of the eco-friendly PLA-based melt electrospun fibrous membrane in the treatment of oily wastewater. Three types of biodegradable fibrous membranes, PLA, PLA/CNF, and PLA/NaCl, were prepared via melt electrospinning. Due to the changes in fiber's crystallinity, morphology, and hydrophilicity, adding CNF and NaCl could improve the oil/water separation efficiency, indicating that they have considerable potential for an effective oily wastewater treatment. image