Abstract - This paper describes the synthesis of nanosilica from rice husk. Synthesis was done by precipitation using different acids,
namely, orthophosphoric acid and nitric acid which yielded nanosilica. The effect of different acids and different solvents (polar and
non-polar) on the size and degree of agglomeration of the silica particles were studied. When precipitation was done without the use
of solvents, the silica particles obtained were non-spherical in shape, whereas, when precipitation was done using polar solvents
(ethanol or 2-propanol), the silica particles were spherical. The use of non-polar solvents (toluene and diethyl ether) resulted in silica
particles that were irregular in shape and in the case of orthophosphoric acid, a high degree of agglomeration was also noted. The
degree of agglomeration was less when orthophosphoric acid was used with polar solvents as compared to nitric acid in conjunction
with polar solvents. As regards the size, it ranged from approximately 70nm to 400nm when either acid was used in conjunction with
polar solvents. When non-polar solvents were used, the silica particles were irregular in shape and the particle size was not estimated.