Bulk superhydrophobic materials: a facile and efficient approach to access superhydrophobicity by silane and urethane chemistries

Abstract

A promising method for constructing ‘bulk’ level superhydrophobicity on CaCO₃ microparticles has been developed by employing silane and urethane chemistries in sequence. Silanol-terminated short-chain polydimethyl siloxane (PDMS) segments were grafted onto a CaCO₃ surface. The particles were characterised by Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and GPC analyses. By the reaction of silanol groups on the surface of CaCO₃ particles with isocyanate functionalities, the crosslinking of particles was accomplished. The resultant coating exhibited a water contact angle >150° with a sliding angle approximately 5–8° on the entire material. The bulk level SH behaviour is attributed to both inter- and intraparticle hydrogen bonding, which was substantiated by FTIR. The rod-shaped morphology of the bulk material was evidenced in SEM images and resulted due to the encasing of well-connected microparticles by PDMS chains.