Synthesis of silica nanoparticles from Vietnamese rice husk by sol–gel method
1 Laboratory of Polymer, Faculty of Chemistry, University of Science-National University of HoChiMinh City (VNU-HCM), 227 Nguyen Van Cu, Ward 4, District 5, HoChiMinh City, 70250, Vietnam
2 Laboratory of Polymer and Composite Materials, Faculty of Materials Science, University of Science-National University of HoChiMinh City (VNU-HCM), 227 Nguyen Van Cu, Ward 4, District 5, HoChiMinh City, 70250, Vietnam
Nanoscale Research Letters 2013, 8:58 doi:10.1186/1556-276X-8-58Published: 6 February 2013
Silica powder at nanoscale was obtained by heat treatment of Vietnamese rice husk following the sol–gel method. The rice husk ash (RHA) is synthesized using rice husk which was thermally treated at optimal condition at 600°C for 4 h. The silica from RHA was extracted using sodium hydroxide solution to produce a sodium silicate solution and then precipitated by adding H2SO4 at pH = 4 in the mixture of water/butanol with cationic presence. In order to identify the optimal condition for producing the homogenous silica nanoparticles, the effects of surfactant surface coverage, aging temperature, and aging time were investigated. By analysis of X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, the silica product obtained was amorphous and the uniformity of the nanosized sample was observed at an average size of 3 nm, and the BET result showed that the highest specific surface of the sample was about 340 m2/g. The results obtained in the mentioned method prove that the rice husk from agricultural wastes can be used for the production of silica nanoparticles.