An eco-friendly and facile method for oil–water separation using the bio-Zn oxide-based superhydrophobic membrane

Abstract

This manuscript presents a novel approach for developing an environmentally friendly and effective oil–water separation membrane. Achieving a superhydrophobic (SH) coating on textile fabric (TF) involved a two-step process. Initially, the surface roughness was enhanced by applying bio-zinc oxide (ZnO) nanoparticles obtained from Thymbra spicata L. Subsequently, the roughened surface was modified with stearic acid, a material known for its low surface energy. The bio-ZnO nanoparticles exhibit a circular morphology with an average size of 21 nm. The coating demonstrated remarkable mechanical stability, maintaining SH properties even after an abrasion length of 300 mm. Chemical stability studies revealed that the prepared membrane retained SH properties within a pH range of 5–11, which ensures robust performance. Absorption capacity measurements showcased different capacities for n-hexane (Hex), corn oil (C.O), and silicone oil (S.O), with consistent performance over 10 absorption–desorption cycles. High oil–water separation efficiencies were achieved for hexane, C.O, and S.O, emphasizing the coating's versatility. Flux rate measurements demonstrated that oil passed through the membrane efficiently, with the highest flux observed for Hex. The prepared SH membrane has superior mechanical and chemical stability and high separation efficiencies, which positions it as a promising candidate for diverse industrial applications. HIGHLIGHTS The manuscript introduces an eco-friendly oil–water separation membrane.; A superhydrophobic (SH) coating was achieved via a two-step process involving improving surface roughness and modifying with stearic acid.; The membrane exhibits good mechanical and chemical stability.; The SH membrane demonstrates efficient oil–water separation for various types of oils, making it highly promising for industrial applications.;

Keywords

• chemical stability
• oil absorption capacity
• oil–water separation
• superhydrophobic
• zinc oxide nanoparticles