Water affinity guided tunable superhydrophobicity and optimized wettability of selected natural minerals

We present a feasible methodology to prepare nonwetting surfaces from natural minerals. Various ranges of silanes were used for the surface grafting, and the best customization was achieved by monochlorosilane. Water affinity analysis of surface functionalized diatomaceous earth was the key aspect of loading tunable wettability on the particle surface. Covalent attachment was confirmed via X-ray photoelectron spectroscopy (XPS), while thermogravimetric analysis, nitrogen adsorption isotherms, and contact angle measurements were used for the evaluation of grafting density and other fundamental features of hydrophobic particles. Diatomaceous earth was chosen as a prototype to develop an efficient strategy for surface modification which can be apposite to another natural particle, the so-called talc, which represents dichotomic performance to water. The present study paves the way for a new approach that can be employed to any proper inherent texture for the production of superhydrophobic powders.