EFFECTS OF GALLIC ACID ON METALS - AN FT-IR STUDY OF COMPLEXES BETWEEN GALLIC ACID AND SAWBLADE STEEL

Previous work by the senior author of this paper showed that the gallic acid (3,4,5-trihydroxy benzoic acid) is capable of producing a strong corrosive effect on sawblade awable steel. The electrochemical reactions involved in this process result in the formation of a solid Fe (III)-gallic acid complex. consisting of two basically different layers or films, endowed with specific appearance, structure and composition. A physical description of this complex is provided in this paper. So is the preliminary assessment of its internal structure and composition. which were examined by Fourier transform spectroscopy.The spectral analysis reveals the existence of water molecules in the initialy formed complex, which gradually alters its composition by losing water. A comparison with the spectrum of a solid Al(III)-gallic acid complex suggests the composition of this ferric complex to be Fe (HL) 4(H2O. Preliminary results of further research carried out at present, indicate that a solid deposit of this nature may possibly have some useful application is practice.