Hydrophobic polyacrylonitrile/pitch electrospun nanofibers for oil spill cleanup: Fabrication, optimization, and kinetic investigations

Abstract

In the present work, the polyacrylonitrile/pitch composite electrospun nanofibers were successfully fabricated to cope with oil spills from the sea surface. The response surface methodology (RSM) was applied to optimize the pitch content, applied voltage, and flow rate to achieve the optimal conditional for absorbing oil. The optimal parameters of pitch content, applied voltage, and flow rate were determined at 18.3 %, 15.3 kV, and 0.95 mL/h, respectively. The hydrophobicity of composite nanofibers was investigated by water contact angle (WCA) analysis. The results showed that the WCA of the composite nanofibers was 139.4°, proving that the fabricated nanofibers were hydrophobic. Compared to pure polyacrylonitrile nanofibers, the polyacrylonitrile/pitch composite nanofibers exhibit better oil-water selectivity and surface roughness under optimized conditions. The composite nanofibers showed good oil absorption for different kinds of oils (up to 42.47 g/g within 5 min), which was 3–5 times that of commercial polypropylene absorbents. The oil absorption of the composite nanofibers was still >70 % after 10 absorption-desorption cycles. Moreover, the absorption kinetics study showed that the pseudo-second-order kinetic model was more suitable for the oil absorption process of the polyacrylonitrile/pitch composite nanofibers. This study explored the potential application value of low-value-added petroleum pitch. The fabricated composite nanofibers have promising applications in the oil/water separation and the absorption of oil spills.