SYNTHESIS AND CHARACTERISATION OF SILICA NANO ARTICLES FROM COCONUT SHELL

Abstract

Silica nano particles are produced from coconut shells .Coconut shells are cleaned, dried and made into pieces. Then it is burned in a muffle furnace at 700°C for 5 hrs to get Coconut Shell Ash (CSA) containing silica nanoparticles. The CSA is made into fine powder and stirred with 2.5N sodium hydroxide solution for 4 hours at 100ºC to produce sodium silicate solution. The filtered solution and stirred with 5N sulphuric acid at 100ºC to precipitate silica gel. The gel is washed to remove sulphates impurities and heated in oven at 70ºC for 15 hours to form amorphous silica. The amorphous silica is refluxed at 90ºC with 6N HCl solution for 6 hours  and washed with warm water to remove alkali.Then the solution is treated with 2.5 N HCl and H₂SO₄ to form white precipitate. The white precipitate is dried in hot air oven for 30 hours to get silica nano particle. The formed silica nano particles were characterized by FTIR, XRD and SEM.