The preparation of PCL/MSO/SiO2 hierarchical superhydrophobic mats for oil-water separation by one-step method

Abstract Hydrophobic polycaprolactone (PCL) membranes with hierarchical structure were fabricated via one-step electrospinning technique. Meanwhile, the addition of the liquid methyl silicone oil (MSO) and hydrophobic silica (SiO 2 ) nanoparticles in the PCL membrane were expected to improve the hydrophobicity of PCL membranes. FE-SEM images showed the microsphere-fiber interlinked hierarchical morphology of PCL/MSO/SiO 2 composite fiber. FT-IR confirmed the formation of PCL/MSO/SiO 2 composite fibers. XPS approved its hierarchical structure of the composition. By comparing with pure PCL membrane which the water contact angle (WCA) was 132.2 ± 1.2°, the WCAs of PCL/MSO and PCL/SiO 2 membrane increased to 143.3 ± 1.2° and 141.7 ± 1.9°, respectively. It was worth noting the WCA of PCL/MSO/SiO 2 composite mat could reach 151.6 ± 1.7° and the sliding angle was 7.4 ± 1.2°. The excellent surface roughness and air-pocket capacity on the hierarchical membranes were believed to contribute to the superhydrophobicity of PCL/MSO/SiO 2 membrane. The unique microsphere-fiber interlinked hierarchical structure and superhydrophobicity of membrane could provide adequate support for oil adsorption and oil-water separation. The maximum n-hexane adsorption capacity of PCL/MSO/SiO 2 membrane was 41.37 g g -1 . Separation efficiency for n-hexane-water mixture of PCL/MSO/SiO 2 membrane was as high as 99.92%. The PCL/MSO/SiO 2 hierarchical superhydrophobic mats indicate the potential applications of environmental-friendly biopolymers as separator.