Aerogel structure used for fabricating superamphiphobic materials with self-cleaning property

Abstract

Since the lotus effect was reported by Barthlott and Neinhuis in 1997, superhydrophobic and superoleophobic materials have received much attention due to special rough morphology and great potential applications in self-cleaning, anti-fouling, corrosion-resistance, and other fields. However, the conventional preparation process of superamphiphobic materials is complicated, including pre- and post-treatments which are used to achieve micro-nano hierarchical structures and low surface energy. In this study, we used methyltrimethoxysilane (MTMS) and 1,1,2,2- tetrahydroperfluorodecyltrimethoxysilane (FAS-17) as precursors and successfully prepared superamphiphobic FAS-17/MTMS composite aerogel via facile sol-gel method. Three-dimensional networks and long fluorocarbon chains formed micro-nano hierarchical structures. As-prepared aerogels had water contact angle (WCA) of 153.68°, oil contact angle (OCA) of 156.28°, water sliding angle (WSA) of 3.32° and oil sliding angle (OSA) of 4.57°, suggesting excellent superamphiphobic performance. Besides external superamphiphobicity, the cross section of sample also exhibited great liquid-repellency with WCA of 160.43° and OCA of 153.43°. Moreover, although cracked into powders with particle size of 0.1 mm, aerogel sample still retained its liquid-repellency with WCA of 122.85° and OCA of 128.01°, respectively. After thermal treatment under 200 ℃ for 2 h, the aerogel sample had WCA of 152.45° and OCA of 135.67°, showing excellent thermal stability. Taking advantage of low thermal conductivity and superamphiphobic properties, superamphiphobic aerogel has potential for fabricating self-cleaning and thermal insulating materials.