Development of Tungsten Oxide Natural Wax‐Based Hybrid Superhydrophobic Cotton Filter for Selective Oil Absorption from Oil‐Brackish‐Water Mixture towards Environmental Applications

Abstract The current article attempted to fabricate tungsten oxide grafted carnauba wax hybridized with polycaprolactone biopolymer to make superhydrophobic coating for cotton fabric towards selective oil absorption applications. Superhydrophobic cotton fabric developed with tungsten oxide grafted carnauba wax hybridized with polycaprolactone coating (CW‐WO(g)‐PCL) were prepared using simple dip coating method. The average static water contact angle value obtained for cotton fabric coated with tungsten oxide grafted carnauba wax with hybridized polycaprolactone was 172°. The surface morphology of the carnauba wax/tungsten oxide/polycaprolactone hybrid coated cotton fabrics were studied systematically using XRD, SEM, AFM, UV–vis, and FTIR spectroscopy techniques. Data resulted from different studies for CW‐WO(g)‐PCL hybrid were further used for the evaluation of mechanical stability, durability, oil/water separation, biodegradability, and water wash out capability for self‐cleaning behavior of coated cotton fabric samples. The coated cotton fabrics exhibit good separation efficiency (oil purity of ≥ 99.9 wt%) with acceptable cyclic ability and high permeation fluxes up to 11,200 ± 100 Lm −2 h −1 . In addition, the separation test water‐in‐oil combination retains 98.9% separation efficiency even after ten repetitions. The results obtained demonstrate that the CW‐WO(g)‐PCL hybrid coated cotton fabrics becomes the exceptional superhydrophobic material and is most suitable for a wide range separation application.