Expired Glucosamine Drugs as Green Corrosion Inhibitors for Carbon Steel in H2SO4 Solution and Synergistic Effect of Glucosamine Molecules with Iodide Ions: Combined Experimental and Theoretical Investigations

Glucosamine is a natural drug widely used for treating osteoarthritis and usually left until it expires, which will cause waste of resources if treated as garbage. However, its molecule contains many heteroatoms, entitling to be potential corrosion inhibitor. In this investigation, the inhibition activities two types expired glucosamine drugs (glucosamine hydrochloride sulfate) on carbon steel were estimated by electrochemical methods in acidic solution. The results demonstrated that mixed-type inhibitors. could inhibit more significantly than sulfuric style at same content, suggesting possible synergistic effect molecules with halide ions. Then, co-adsorption behaviors sulfate iodide ions studied experimental research, well theoretical investigations. indicated enhanced when was utilized combination electronic structures played critical role Neutral interact metallic surface vertically through amino carbonyl groups, while protonated able adsorb parallel help multiple functional groups. Since would positively charged solution, they difficult solid cations. When presented, preferentially adsorbed induced negatively charged. Therefore, using bridge form protective film mitigate corrosion.