Green superhydrophobic surface engineering of PET fabric for advanced water-solvent separation

This paper presents the preparation of the PET membrane for effective organic solvent separation achieved through an advanced superhydrophobic surface engineering of PET fabric utilizing biomimicry and a green chemistry approach. The superhydrophobicity of the PET surface was reached through a hierarchical nanocomposite coating that involved the integration of biomimetic polydopamine (PDA) coating, green-synthesized zinc oxide (ZnO) nanoparticles (NPs), and non-fluorinated quaternary ammonium cation silane (Si-QAC) coverage. The morphology and surface chemical composition of the resultant Si-QAC/ZnO/PDA@PET membrane were characterized by SEM, EDS, FT-IR, XRD, and AFM analysis. The surface topography and water contact angle were also correlated with surface roughness and its superhydrophobicity. The resulting Si-QAC/ZnO/PDA@PET membrane exhibited promising superhydrophobic properties, characterized by a water contact angle ranging from 150° to 160° and a roll-off angle between 5° and 2° as well as stability against severe conditions, including acidic and alkaline exposure, mechanical abrasion, and UV radiations. Moreover, the Si-QAC/ZnO/PDA@PET membrane exhibited bacterial repulsive properties against E. coli and Staphylococcus sp. The separation efficiency of various aliphatic and aromatic organic solvents (n-hexane, toluene, chloroform, and petroleum ether) from water higher than 90 % was also observed, making the membrane a potential candidate for different industrial applications, particularly for the separation of organic solvents from water.