Fluorine-free Superhydrophobic Stearic Acid Modified Kaolin Nanoparticles for Self-cleaning Silicone Rubber Surface

Abstract

This study introduces fluorine-free nanoparticles to innovate superhydrophobic surfaces for self-cleaning applications, addressing environmental concerns linked to fluorine-based compounds. The method involves modifying kaolin nanoparticles with stearic acid and integrating them into silicone. The surface of stearic acid-kaolin nanoparticles exhibits a contact angle of 149.4° ± 3.3, while the resulting composite film exhibits a contact angle of 113.9° ± 5.8. The surface roughness of the silicone rubber surfaces increases proportionally with higher concentrations of stearic acid-modified kaolin nanoparticles. Field Emission Scanning Electron Microscopy (FESEM) analysis demonstrates the successful coverage of kaolin nanoparticles-stearic acid on resulting film. Self-cleaning performance is evaluated by simulating the deposition of graphite powder onto the surfaces and subsequently observing the behaviour when water is dropped on them revealing their remarkable self-cleaning properties.