Organic functionalization of Silicalite-1 nanocrystals by ultrasonic treatment in methanol

Silicalite-1 nanocrystals with organic functional groups were prepared by a simple ultrasonic treatment in methanol. The adsorption of methanol on Silicalite-1 nanocrystals was studied in detail by attenuated total reflection infrared (ATR-IR) spectroscopy, diffuse reflectance fourier transform infrared spectroscopy (DRIFTS), thermogravimetric (TGA) analysis and nitrogen adsorption. The results indicate that methoxy (–OCH3) groups were chemically adsorbed onto the external surface of Silicalite-1 nanocrystals, via terminal silanol groups, which were thermally stable up to 420 °C. The organic functionalization enhanced the hydrophobicity of Silicalite-1 nanocrystals, which has proven to be very useful for fabricating monolayer zeolite films.