Surface modification of nettle fibers by grafting to improve oil sorption capacity

In this study, an attempt was made to enhance the oil sorption capacity of nettle fibers by grafting of butyl acrylate. Box–Behnken experimental design was used to study the effect of parameters such as reaction time, reaction temperature and monomer concentration-to-fiber ratio on graft add-on (%) and oil sorption capacity. At 4-h reaction time, 70℃ temperature and 2% monomer concentration-to-fiber ratio, highest graft add-on (%) and oil sorption were attained. Maximum oil sorption capacity of grafted nettle was 36.60 g/g and 25.56 g/g against crude oil and vegetable oil, respectively. Grafted nettle fibers were also subjected to characterization by Fourier-transform infrared spectroscopy, scanning electron microscopy and contact angle tests. Reusability test results showed that grafted nettle exhibited better oil sorption capacity than unmodified nettle even after seven sorption–desorption cycles. It is also observed that the oil sorption capacity of grafted nettle was higher than that of commercial polypropylene material. Based on these results, it is concluded that functionalized nettle prepared by grafting technique can be a potential material for oil spill treatment.