Effect of thermal treatment on hydrophobicity of methyl-functionalised hybrid nano-silica particles

摘要

Methyl silica particles with superhydrophobic nature were prepared by sol-gel hydrolysis from methyltrimethoxysilane with tetraethyl orthosilicate. The structure and stability of surface modified methyl silica were evaluated as a function of temperature over a range of 393-873 K. Thermal stability of methyl silica was analysed using thermogravimetric analysis. The structure and morphology were evaluated by X-ray diffraction and transmission electron microscopy. In addition, the effect of temperature on the chemical composition of thermally treated methyl silica was analysed by energy-dispersive X-ray diffraction and Fourier transform infrared spectroscopy studies. A decrease in hydrophobicity of the methyl silica from 124° to 103° with increase in temperature in the range of 393-873 K was observed. Reduction in hydrophobicity at high-temperature treatment was observed due to the removal of methyl group from the methyl silica. The hydrophobic nature of methyl silica was stable up to 873 K. Thermal treatment shows a great effect on specific surface area of methyl silica that was increased from 488.59 to 575.59 m~2g~(-1) with increasing temperature.