Fabrication and characterization of superhydrophobic halloysite nanotube-based colored hybrid coatings with thermal, chemical, and environmental durability and self-cleaning ability on glass substrate by spray coating technique

Abstract

Superhydrophobic colored coatings fulfil the needed requirements in various application areas. In this study, superhydrophobic colorful glass surfaces with chemical and environmental durability and self-cleaning ability were constructed using Methylene Blue (MB) loaded activated halloysite nanotube (A-Hal/MB), 1H,1H,2H,2H-perfluorooctyltriethoxysilane (PFOTES), tetraethoxysilane (TEOS), and polydimethylsiloxane (PDMS) by the spray coating technique and their characterization and stability studies were performed. Optimum reaction and process conditions such as the amounts of organosilane compounds used, sol-gel reaction time and curing time were determined to obtain a superhydrophobic colored glass surface. Water contact angle (WCA) of the colorful glass surfaces coated with A-Hal/MB/PFOTES and A-Hal/MB/PFOTES@PDMS was measured to be 163.0° and 156.0°, respectively. Coated A-Hal/MB/PFOTES and A-Hal/MB/PFOTES@PDMS composites were characterized by TEM, SEM, mapping, EDS, FTIR, XRD, and TGA measurements. The achievement of coating process on the glass surfaces was proved by XPS, AFM, and WCA analyses. Stability studies exhibited that the chemical, mechanical, thermal, and environmental stabilities of the colorful glass surface coated with A-Hal/MB/PFOTES@PDMS are better than those of the glass surface coated with A-Hal/MB/PFOTES. The results showed that the fabricated Hal-based colored superhydrophobic glass surfaces can be used in different industries.