Synthesis and Characterization of Nano Silica from locally available Laterite clay

S. Naz, S. Khattak, N. Amin
abdul wali khan university mardan pakistan,
Pakistan

Keywords: laterite clay, sodium hydroxide, potassium hydroxide, sodium silicate, nanosilica

Summary:

This paper report the synthesis and characterization of Nano silica from locally available laterite clay using sol-gel method. The elimination of alumina and iron oxide contents in the precursor was achieved by thermal treatment at 120 ℃ for 2 hours followed by acid treatment via 2M Hydrochloric acid. The silica enriched residue was reacted with 3M sodium and 3M potassium hydroxide to convert it into sodium and potassium silicate respectively and was then reacted with hydrochloric acid and methanol. The degree of thermal treatment of starting material with both the alkalies was optimized for maximum yield and purity of the nano particles. The product was analyzed using X-ray florescence (XRF), X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). It was observed that product was spherical, agglomerated and amorphous in nature. The obtained Nano silica was found to have 97% and 95% purity for sodium and potassium hydroxide respectively. The renewable generated Nano-silica is expected to play substantial role as a pozzolanic activator in construction section.