Masoud Salavati-Niasari and Jaber Javidi Pages 705 - 712 ( 8 )
Silica nanoparticles were synthesized from rice husk ash at room temperature by sonochemical method. The feeding rate of percipiteting agent and time of sonication were investigated. The nanostructure of the synthesized powder was realized by the FE-SEM photomicrograph, FT-IR spectroscopy, XRD and XRF analyses. These analytical observations have revealed that the nano-sized amorphous silica particles are formed and they are spheroidal in shape. The average particle size of the silica powders is found to be around 50 nm. The as-synthesized silica nanoparticles were subsequently modified with chlorosulfonic acid and prepared silica sulfuric acid nanoparticles, which were employed as an efficient catalyst for the acylation of alcohols and phenols with acetic anhydride in excellent yields under solvent-free conditions at room temperature. This reported method is simple, mild, and environmentally viable and catalyst can be simply recovered and reused over 9 times without any significant loss of its catalytic activity.
Acetylation, rice husk ash, silica sulfuric acid, silica, sonochemical, chlorosulfonic acid, heterogeneous catalyst, alcohols and phenols, particle size, nanoparticles
Institute of Nano Science and Nano Technology, University of Kashan, Kashan, P.O. Box 87317-51167, I.R. Iran.