Fabrication of fluorine-free superhydrophobic coatings from montmorillonite with mechanical durability and chemical stability

Abstract

In this study, durable superhydrophobic coatings were successfully prepared by modifying montmorillonite with stearic acid and organosiloxane, and this procedure was simple, efficient, and environmentally friendly. Different from the previously reported methods, the micro-/nanostructures of the superhydrophobic coatings were constructed by using the abundant natural montmorillonite as the building blocks. The surface topography of the coating was analyzed with a scanning electron microscope, while element compositions and functional groups were characterized by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy, respectively. The as-prepared superhydrophobic coatings showed excellent wear resistance, and could maintain their superhydrophobicity after sandpaper abrasion for 180 cm in length. Apart from the superb wear resistance, the obtained superhydrophobic coatings also displayed strong acid resistance and anti-UV properties. In addition, the as-coated fabric not only possessed superhydrophobicity and the ability of oil–water separation, but also exhibited excellent fire resistance because of the thermal stability of MMT particles. Notably, the favorable comprehensive performance of the as-prepared coatings was indicative of their potential applications in oil/water separation and some harsh conditions, and as outdoor protective materials.