Preparing nanosilica particles from rice husk using precipitation method

Abstract

Nanosilica was extracted from rice husk, which was locally collected from the Iraqi mill at Al-Mishikhab district in Najaf Governorate, Iraq. The precipitation method was used to prepared Nanosilica powder from rice husk ash, after treating it thermally at 700°C, followed by dissolving the silica in the alkaline solution and getting a sodium silicate solution. Two samples of the final solution were collected to study the effect of filtration on the purity of the sample by X-ray fluorescence spectrometry (XRF). The result shows that the filtered samples have purity above 98%, while the non-filtered sample purity was around 96 %. The structure analysis investigated by the X-ray diffraction (XRD), found that the Nanosilica powder has an amorphous structure in nature. Also, it shows a broad peak at (2θ = 22.25°- 22.55°). The particle size distribution was determined by Atomic force microscope (AFM), the results gave that the average diameter equals 52.83 nm and dimension range in 30-75 nm, while B.E.T. analysis confirms a high surface area around 618 m2/g. FT-IR Spectra experimental data showed the presence of hydrogen-bonded silanol group (Si-O-H) and siloxane group (Si-O-Si) which proved the high purity of Nanosilica particles.