Electrospun Nanofibers with Superhydrophobicity Derived from Degradable Polylactide for Oil/Water Separation Applications

Polymeric nanofibers with superhydrophobic property have attracted vast interest in various applications, especially oil/water separation. In this work, superhydrophobic PLA nanofibers have been fabricated by an electrospinning process and treatment with a hydrophobic agent, alkyl ketene dimer (AKD). AKD consists of a functional group that is specifically reactive toward hydroxyl groups. Glycerol is employed as a template, providing –OH functional groups for the PLA matrix. The electrospun fiber mats were then immersed in AKD solution, in which a grafting reaction took place, leading to an increase in hydrophobicity of the fiber mats. Chemical structures and properties of the materials were then characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), water contact angle (WCA) measurement, and oil absorption ability. Oil/water separation efficiency of the degradable nanofibers was assessed for their use for oil-contaminated water treatment. The fiber mats, after AKD treatment, show super-hydrophobic properties, with oleophilicity. The material possesses high oil absorption rates with absorption capacities higher than 10 g/g fibers and adsorption–desorption cycle abilities of greater than ten cycles. As these materials are derived from a degradable polymer, they are environmentally-friendly and can easily be disposed of after use. These have many advantages over conventional materials.