Mechanochemical Coupling of Alkylsilanes to Nanoparticles for Solvent-Free and Rapid Fabrication of Superhydrophobic Materials

High Resolution Image Download MS PowerPoint Slide Excellent repellency toward water is one of the main characteristics of superhydrophobic coatings that endow application potential in various areas. However, the complex and time-consuming process involved in preparing universally applicable superhydrophobic coatings, especially the step that involves modifying intrinsically hydrophilic inorganic oxide nanoparticles with hydrophobic alkylsilanes, limits their practical applications. This study demonstrates a rapid and eco-friendly approach to preparing superhydrophobic surfaces by chemically grafting alkylsilane molecules onto silica nanoparticles using a mechanochemical process. The key advantages of this approach are (i) rapid process with preparation times that are orders of magnitude shorter than those of conventional methods, (ii) zero-solvent usage, and (iii) overcoming the need for tedious separation and drying steps. The resultant surface exhibits superhydrophobicity with a water contact angle of 172° and a sliding angle of 1°. A monolith prepared by compressing the powder exhibits superhydrophobicity, durability, and antifouling ability against urine. The superhydrophobic surface inhibits the growth of two of the most common pathogenic bacteria. The bacterial growth was reduced by 10 7.07 for Escherichia coli and 10 5.78 for Staphylococcus aureus . The proposed approach is practical, swift, and cost-effective, making it a scalable and eco-friendly technique for the solvent-free preparation of superhydrophobic surfaces.