tailieunhanh - Study the Corrosion Inhibition of Mix of Caffeine and 1.0 g/l Iodide for CT3 Steel in 1 M HCl Solution by Electrochemical Methods

Corrosion inhibition of mild carbon steel, CT3, in M HCl solution by iodide (with different concentrations, from to ), mix of caffeine and g/l iodide was investigated by electrochemical methods and micro surface observations (SEM). | VNU Journal of Science: Natural Sciences and Technology, Vol. 33, No. 3 (2017) 105-111 Study the Corrosion Inhibition of Mix of Caffeine and g/l Iodide for CT3 Steel in 1 M HCl Solution by Electrochemical Methods Truong Thi Thao* Faculty of Chemistry, Thai Nguyen University of Science, Thai Nguyen University, Tan Thinh, Thai Nguyen, Vietnam Received 05 April 2017 Revised 30 May 2017; Accepted 28 June 2017 Abstract: Corrosion inhibition of mild carbon steel, CT3, in M HCl solution by iodide (with different concentrations, from to ), mix of caffeine and g/l iodide was investigated by electrochemical methods and micro surface observations (SEM). Experiment result showed that: (1) the inhibition efficiency increaseed with increased of iodide concentration; iodide acted as a mix – type inhibitor but inhibits anodic reaction was predominant. (2) Mix of g/l iodide and caffeine acted as a typical mix – type inhibitor. The current densities of both of anodic and cathode declined when concentration of caffeine was g/l or more, inhibition efficiency max was approximately 96% at concentration of g/l caffeine, the inhibition efficiency maintained relatively stable within 5 days. Keywords: Mix of iodide and caffeine, CT3 steel, corrosion inhibitor. 1. Introduction inhibitors and the search for non-toxic natural inhibitors to reduce corrosion of metals. The majority of inhibitors used in industry in acid corrosion are organic compounds consisted of nitrogen, oxygen and sulfur atoms. Inhibitors that contain double or triple bonds take an important part in facilitating the adsorption of these compounds onto metal surfaces as well, since a bond can be formed between the electron pair and/or the -electron cloud of the donor atoms and the metal surface, there by reducing corrosive attack in acidic media. We have done some research using caffeine as corrosion inhibitors [1-2]. Other authors have also reported that caffeine can inhibit .