A robust superhydrophobic and oleophobic coating with short chain perfluoroalkyl group and flower-shaped SiO2 nanoparticles

Low-surface-energy fluorocarbon-based materials are widely used in superhydrophobic and oleophobic coatings. The fabrication of oil-repellant coatings, however, is particularly challenging due to the low surface tension of oils and the nondegradable of long-fluorocarbon compounds (CnF2n+1, n ≥ 8). In this work, superhydrophobic and oleophobic functional nanoparticles were prepared based on flower-shaped silica and environmentally friendly short chain perfluoroalkyl group. The experimental results show that a low-surface-energy coating surface (water contact angle of 152.5 ± 0.4°, oil contact angle of 142.2 ± 0.8°) can be obtained by using triethoxy(1H,1H,2H,2H-nonafluorohexyl)silane (CH3CH2O)3SiCH2CH2(CF2)3CF3 (C4FTES) and methyltriethoxysilane (MTES) to co-modified flower-shaped SiO2 nanoparticles (flower-shaped MF-SiO2). The analysis of morphology and chemical components of flower-shaped MF-SiO2 displayed a synergistic effect by providing a multi-scale rough structure of flower-shaped SiO2 which minimize contact at the liquid/solid interface, and promotes the distribution and accumulation of the outermost -CF3 groups of nanoparticles as evidenced by the angle-resolved X-ray photoelectron spectrum (AR-XPS) tests. Furthermore, flower-shaped MF-SiO2 nanoparticles have good mechanical stability under the action of adhesive, which means the flower-shaped MF-SiO2 nanoparticles as a promising candidate for superhydrophobic and oleophobic coating materials.