%0 Journal Article
%T Electrochemical Behavior of Malachite Green in Aqueous Solutions of Ionic Surfactants
%A Mohammad Mijanur Rahman
%A M. Yousuf A. Mollah
%A M. Muhibur Rahman
%A Md. Abu Bin Hasan Susan
%J ISRN Electrochemistry
%D 2013
%R 10.1155/2013/839498
%X Electrochemical behavior of malachite green (MG) oxalate in aqueous solution was studied in the presence of a cationic surfactant, cetyltrimethylammonium bromide (CTAB), and an anionic surfactant, sodium dodecyl sulfate (SDS) at a glassy carbon electrode using cyclic voltammetry. The electrochemical oxidation of MG has been characterized as an electrochemically irreversible diffusion-controlled process. Oxidative peak current sharply decreased with increasing SDS concentration, while a slight increase with increasing [CTAB] was apparent. The apparent diffusion coefficient, the surface reaction rate constant, and the electron transfer coefficient of MG clearly show correlation of the electrochemical behavior with the dissolved states of the surfactants. Electrochemical observations together with spectrophotometric results at varying surfactant concentrations provide evidence of interaction of MG with the surfactants to varying extent depending on the type of the surfactant and the concentration. 1. Introduction Triphenylmethane (TPM) dyes, an important class of synthetic organic compounds, have been a promising material for diverse applications, which inter alia include the following: as fungicides in aquaculture, as parasiticides in pharmaceuticals, as dye materials in industry, and as redox mediators, bioprobes, and pH indicators in both fundamental and applied sciences [1¨C6]. A proper understanding and development of fundamental knowledge base of physicochemical properties of TPM dyes have therefore attracted significant attention. Techniques so far employed for this are polarography [7], conductometry [8, 9], potentiometry [10], spectrophotometry [11, 12], electrochemical methods [13], membrane selective electrode [14], and so on. Dyes of TPM backbones such as malachite green (MG), crystal violet [15], ethyl violet [16], and victoria blue B [17] are electrochemically active, and recent surge of interest has been the exploration of the redox behavior of such dyes. Among the TPM dyes the prospect of MG (chemical structure shown in Scheme 1) for versatile applications [1] prompted many researchers to study the electrochemical behavior of MG for development of electrochemically switchable devices. The electrochemical oxidation of MG occurs at -containing lone-pair electron, and the reduction process is due to reduction of oxidized tertiary amino group of MG [2, 10]. In acidic aqueous solutions, the anodic oxidation of MG leads to the formation of the oxidized form of -tetramethylbenzidine (TMB) ([ -biphenyl]- -diamine), that is, TMBOx whereas the
%U http://www.hindawi.com/journals/isrn.electrochemistry/2013/839498/