Nanosilica: Pre-treated rich husk was burned at 650 °C for 1 hour[Asawapisit et al., 2005]. Nanosilica was prepared by following Liou and Yang, 2011. Dissolve rice husk ash into 1.5 M NaOH at the solid/liquid radio (S:L) of 1:6 then heat and stir for one hour. The mixed solution was centrifuged to remove solid residues. Then, add 1.0 HCl until neutral (pH=7) and curing temperature 50°C for a period of 12 hours. Next, researchers used deionized water for remove chloride. Finally,the gels dried at 80°C for 48 hours.