Hydrophobic-superoleophilic coating derived from silica with hexamethyldisilazane and methyltrimethoxysilane applied as separator cotton of oil water

Abstract

Oil spills in seawater are a burden on the aquatic environment. Many separation methods have been carried out, but the effectiveness and efficiency of these methods are constrained. For this reason, the oil-water separation method uses a cotton fabric coated with a modified geothermal silica precursor using alkylsilane. The research was carried out by preparation of a superhydrophobic-superoleophilic layer on a cotton fabric substrate with an affordable sodium silica precursor, and a surface changing agent using Hexamethyldisilazane (HMDS) and Methyltrimethoxysilane (MTMS) in an oil-water separation application. The research stages include preparation of sodium silicate precursor solution, mixing Na-silicate precursor with Methyltrimethoxysilane precursor, coating with Hexamethyldisilazane hybrid sole on a cotton fabric substrate. The variables used were the ratio of sodium-silicate concentration/mtms, i:e (1.0:0.1); (1.0:0.8); (1.0:1.0); (1.0:1.5); (1.0:2.0) and the variation of Hexamethyldisilazane based on the product by weight of silica in na-silicate are (0%, 20%, 40%, 80%, 150%, and 200%). The response data were obtained in the form of a Water Contact Angle (WCA) to the cotton fabric that has been coated with the silica-based coating. The best Water Contact Angle test results were characterized using FTIR, SEM-EDX, XRF, BET, and acid-base resistance tests. The results showed that the best Water Contact Angle was obtained at 146.5° under hydrophobic conditions supported by the presence of a water-repellent layer on the surface of the fabric. The resistance of the coating in a strong acid-base environment was demonstrated by the continued formation of round droplets on the surface of the coated Japanese cotton fabric, this result was obtained after the coated cotton fabric was soaked overnight. The oil-water separation efficiency can reach up to 100% and the flux reaches 112.5 L/m2. h2 with repeated cycles of 3 times, the coating shows stable and efficient separation results so that it has promising potential with high durability.