Majid Monshizadeh - Department of Material Engineering and Metallurgy, Imam Khomeini International University, Ghazvin, Iran
Masoud Rajabi
Mohammad Hossein Ahmadi - Department of Chemistry, Imam Khomeini International University, Ghazvin, Iran
Vahid Mohammadi - Department of Chemistry, Imam Khomeini International University, Ghazvin, Iran

This work is presented as studies on the preparation of rice husk ash by burning at 777 oC for 3 and 6 h, respectively. Consequently, silica content obtained after heat treatment at 777 oC for 6 h was 981149. of rice husk ash (RHA) which was purified by alkaline extraction method by using 215N sodium hydroxide. Infrared spectral data supported the presence of hydrogen bonded silinol group and the siloxane groups in silica. Subsequently, the RHA was subjected to precipitation method in order to produce nanosilica. The precipitation was done by refluxing silica from RHA in boiling 215N NaOH. X-ray diffractograms and diffraction pattern showed that the obtained products were amorphous nanosilica. The size of the particle is determined from the number averaged particle radius by LPS that show Nanosilica particles which obtained from the rice husk ash were in the agglomerate form which dimension of 17-37 nm.

Rice husk ash, Nano silica, Precipitation Method