Polylactic acid/multi-wall carbon nanotubes composite fibrous membrane and their applications in oil-water separation

Because of the rising consumption of oil, the oily pollutants contained in wastewater have caused great damage to the ecological environment. Herein, we report a novel composite PLA fibrous membrane for oil-water separation. First, a series of hydrophobic polylactic acid/multi-wall carbon nanotubes (PLA/CNTs) composite fibrous membranes were fabricated via electrospinning. To modify the membranes’ crystalline structure, the as-prepared PLA/CNTs composite fibrous membranes were subsequently treated by being immersed in an acetone/ethanol mixed solution for 5 min. FTIR and XRD were applied to thoroughly investigate the crystalline modification's mechanism and effects on the oil-water separation capability of the as-prepared composite fibrous membranes. With the introduction of CNTs and the crystalline modification, a low polar, rough and porous surface was endowed to the as-prepared fibrous membranes, enhancing their hydrophobicity and oil-water selectivity. The oil uptake of the as-prepared fibrous membrane could reach 114.01 g/g. The water contact angle in the air could reach 134.2° while the water contact angle under oil can reach 157.3° Therefore, such high separation capability in the oil-water mixture will make the PLA/CNTs composite fibrous membranes promising candidates for oil-water separation applications.