The Potential of Sodium Silicate from Rice Husk as Corrosion Inhibitor on Mild Steel

Study of sodium silicate from rice husks as coating material is reported. The extraction was conducted via precipitation method with sodium hydroxide, nitric acid and ethanol at pH 8. The resulting silica was tested as hydrophobic coating by coating it on a glass surface. Based on the value of the contact angle, silica has good hydrophobic properties. The highest hydrophobic properties were obtained from sample, which labeled as Si10A:Si5B with an average contact angle of 105.3 °. Investigation of the potential application of sodium silicate as an inhibitor of corrosion has been conducted by coating it on steel surfaces. The effect of the concentration of sodium silicate was conducted at 0, 10, 20 and 30 ppm and found that the morphology of steel coated with 20 ppm has the lowest corrosion rate with 81 % inhibition efficiency. HIGHLIGHTS The amorphous silica was successfully synthesized from rice husk using the precipitation method The silica from rice husk shows hydrophobic properties with a contact angle of 105.3 ° Sodium silicate from rice husk has the ability as a corrosion inhibitor and has an inhibition efficiency of 81 % for 20 ppm GRAPHICAL ABSTRACT