Effect of Chitosan on the Corrosion Inhibition for Aluminium Alloy in H2SO4 Medium

Abstract

Aluminum AA5052 is an inexpensive and lightweight metal that has been used in a variety of applications, including the Bipolar Plate in Proton Exchange Membrane Fuel Cells (BPs PEMFC). The alloy has good electrical conductivity and low corrosion. Corrosion rate (CR) increases during PEMFC operation with increasing temperature. Inorganic dyes, such as chromate, are commonly used to reduce metal corrosion. Unfortunately, they are toxic and have a negative impact on the environment. Chitosan, which is a green, cheap, non-toxic, and environmentally friendly organic solvent, can be used to solve this problem. Electrophoretic Deposition (EPD) technique was used to coated the surface of AA5052 with chitosan. CR was measured using electrochemical and weight loss methods (in 0.5 M H2SO4). The best research results are as follows. The lowest CR values were obtained at the EPD time of 20 min at a chitosan concentration of 0.5% wt. The results of the study using the weight loss method indicated that after soaking for 72 hours, the chitosan inhibitor can reduce the corrosion rate (CR) with an inhibitor efficiency of 87.89%, while the electrochemical method obtained a higher efficiency of 95.12%. An increase in temperature will result in a decrease in the efficiency of the inhibitor. Testing with SEM-EDX, after being coated with chitosan inhibitor, the metal surface looks smoother and the Al composition is reduced and it is detected that there is adsorption of O, N and S elements that coated the metal to form insoluble complex compounds, so the corrosion rate decreases.

Performance of D-galactose for Protecting The Corrosion Rate of Aluminium Alloy 5052 (AA5052) in Acidic Environment

“…The material preparation was performed as described by Arwati [11]. The aluminium bipolar material used in this work was aluminium with the type AA5052 (SIGMA No.…”

“…The treatment on the AA5052 surface was priory performed using the ASTM method described by Arwati [11] before the EDP process was conducted. The AA5052 sample was rinsed trice using deionized water and then dried using a hairdryer.…”

“…D-galactose deposited on the AA5052 surface was performed using the electrophoretic deposition (EDP) technique. A total of 5.0 g/l of D-galactose solution was used as substrate in the EDP and applied voltage of 8.0 V (DC power supply) for 20 minutes [11]. All experiments were conducted in triplicate.…”

“…The EIS tests for AA5052 and G-AA5052 were conducted by using a Potentiostat (Autolab PGSTAT128N, Netherlands). The EIS analyses were performed at the frequency range of 100 kHz to 5 MHz, AC amplitude of 10 mV as described by Arwati [11]. The EIS data were then presented in Nyquist curves for AA5052 and G-AA5052.…”

“…Principally, the EPD technique is based on the deposition of charged particles dispersed in the suspension system due to the influence of the electric field. The EPD using organic substrate (i.e., chitosan, Arabic gum, D-galactose) is a new approach that can be used to reduce the corrosion rate [10,11]. Based on our previous work, the corrosion rate (CR) and efficiency were obtained 10.70 mpy and 81.30%, respectively, using the Arabic gum with the concentration of 0.5 g/l in 0.5 M H2SO4 [12]-It is well known that D-galactose is one of the arabic gum monomers [13]; therefore it can also be used as organic substrate.…”