Polylactic acid/ zinc oxide decorated multi-wall carbon nanotubes fibrous membranes and their applications in oil-water separation

The frequent occurrence of oil spills and oily wastewater leakage has increased the demand for oil-water separation materials with good hydrophobicity. Herein, a novel polylactic acid composite fibrous membrane is reported to address this problem. The zinc oxide decorated multi-wall carbon nanotubes were synthesized via the hydrothermal reaction and composited with polylactic acid to prepare a series of fibrous membranes via electrospinning. The wetting behavior of the prepared fibrous membranes conformed to Cassie's equation, proving that the introduced zinc oxide-decorated multi-wall carbon nanotubes enhanced the surface roughness of the prepared fibrous membranes. Such rough surfaces of the fibrous membranes have enhanced the hydrophobicity and increased the water contact angle to 138.5° (in air) and 159.3° (under oil), respectively. The oil uptake of the prepared fibrous membranes has reached 73.2 g/g. The prepared fibrous membrane was able to absorb oil on the water surface, underwater, or emulsion. Therefore, the prepared polylactic acid/zinc oxide-decorated multi-wall carbon nanotubes fibrous membrane can be a good candidate material for treating oily wastewater.