Preparation and Characterization of Raspberry-like SiO 2 Particles by the Sol-Gel Method

Raspberry-like SiO 2 particles with a nano-micro-binary structure were prepared by a simple sol-gel method using tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) as precursors. The chemical components and morphology of the SiO 2 particles were characterized by Fourier transform infrared spectroscopy (FT-IR) and a Transmission electron microscope (TEM). The surface topography and wetting behaviour of the raspberry-like SiO 2 surface were observed with a Scanning electron microscope (SEM) and studied by the water/oil contact angle (CA), respectively. The thermal stability of the prepared SiO 2 particles was characterized by TGA analysis. The results show that the highly dispersed SiO 2 particles initially prepared by the sol-gel method turn into raspberry-like particles with during the aging process. The raspberry-like SiO 2 particles show superhydrophobicity and superoleophilicity across a wide range of pH values. The SiO 2 particles were thermally stable up to 475°C, while above this temperature the hydrophobicity decreases and finally becomes superhydrophobic when the temperature reaches 600°C. The raspberry-like SiO 2 particles which were prepared have potential applications in the fields of superhydrophobic surfaces, water-oil separation, anti-corrosion and fluid transportation.