Highly Washable and Reusable Green Nanofibrous Sorbent with Superoleophilicity, Biodegradability, and Mechanical Robustness

Abstract

Dealing with the aftermath of a disastrous oil spill proves to be challenging with the current remedies as it poses issues of secondary pollution, low oil recovery, and non-biodegradability. Hereby, a series of green poly(lactic acid)/poly(3-hydroxybutyrate) (PLA/PHB) nanofibrous membranes with uniform 400–700 nm average diameters were successfully fabricated through a simple and scalable electrospinning process. The incorporation of the designed PHB-rubber filler, PHB-di-rub, into PLA green biocomposite contributed to a roughened nanofiber surface and displayed excellent oleophilic–hydrophobic surface wettability due to its complex nanofibrous structure with high surface area and surface roughness. The highly extensive and aligned nanofibers simultaneously improved both the stiffness and strength of the green nanofibrous membranes due to strong filler–matrix interaction and highly stretched nanofibers during deformation, with close to 6-fold enhancement in the elongation and 30-fold increment in toughness, in conjunction with a tensile strength > 4 MPa. The resultant green nanofibrous membranes show huge potential as a sorbent as they absorb up to 15 times their weight in oils and also display promising usage in an oil-in-water emulsion. Remarkably, these green, non-cytotoxic, biocompatible sorbent materials are highly washable and reusable as the adsorbed oil could be easily washed off by common organic solvents and subsequently air-dried instantaneously at ambient temperature, demonstrating the excellent reusability, recyclability, and oil recovery. These exceptionally toughened and durable green PLA/PHB nanofibrous membranes show tremendous potential as an effective and efficient sorbent to wrestle with an oil spillage disaster without posing secondary pollution to our environment.