SYNTHESIS AND PERFORMANCE OF NANOSILICAS FROM IRAQI RICE HUSK ASH AS A RENEWABLE CORROSION INHIBITOR FOR LOW CARBON STEEL IN AN ACID SOLUTION

Abstract

In the present work, corrosion inhibition for low carbon steel in  a 1M H₂SO₄ solution was prepared successfully from Iraqi rice husk (IRH). The weight loss and potentiostatic methods were used to study the corrosion rate. Increasing  the acid concentration led to an increase in the corrosion rate of the electrode. The variable conditions in this investigation were 100 to 1000 ppm of Iraqi rice husk ash at 25^oC.  The concentrates acted as a compelling consumption inhibitor for the gentle steel in  an acidic medium. The hindrance process was credited to the development of an adsorbed film of  the inhibitor on the metal surface, which protected the metal against corrosion.

The inhibition efficiency was found to increase with increasing inhibitor concentration up to maximum of 92.7% for 1000 ppm at 25 ^oC. The corrosion rate without an inhibitor was 7.2 MPY while with an inhibitor, it was 0.52 MPY , demonstrating that the corrosion rate improved more than 90%. The immersion time (3h) at 25^oC also improved the corrosion resistance. The results show that Iraqi rice husk Ash could serve as an excellent green- friendly corrosion inhibitor. FTIR results indicated that this waste product (IRH) contained different chemical bonds (i.e C-C, CH₂, C-O-C and cellulose) and produced barrier layer that protected the  steel surface