Characterization and application of superhydrophobic and superoleophilic OTS-LDH/melamine sponge

The n-octadecyltrichlorosilane (OTS) had been coated onto the layered double hydroxides (LDH), and the resultant composite of OTS-LDH was further loaded on the surface of melamine sponge by a soaking method to obtain the OTS-LDH/melamine sponge for efficient oil adsorption in this work. The surface chemical compositions of the OTS-LDH/sponge and its precursors were characterized by EDS, XPS, and FTIR. The results from EDS, XPS, and FTIR showed that the OTS had been successfully coated on LDH. The surface morphologies from SEM for the melamine sponge before and after modification illuminated that the surface skeleton of the OTS-LDH/sponge took a rough micro-nanostructure, and the surface had been loaded with the low surface energy material of OTS, which made the OTS-LDH/sponge display the superhydrophobic properties. The experiments of oil-water separation proved that the OTS-LDH/sponge took an excellent oil-water efficiency, and the modified sponge still took the better oil-water separation performance with an oil adsorption capacity of 13.7-21.1 times of the mass of the pristine sponge even after undergoing repeated extrusion for 60 times during the repeated cycle test.

Automated summary

The study involved coating OTS-LDH composite on the surface of a melamine sponge to create a superhydrophobic material with excellent oil adsorption capacity. The modified sponge showed great oil-water separation efficiency, with an oil adsorption capacity 13.7-21.1 times higher than that of the pristine sponge. Even after repeated cycles of testing, the modified sponge maintained its superior performance.