UV-Vis studies of methyl red in the presence of sodium dioctylsulfosuccinate/acetone and sodium dioctylsulfosuccinate/acetone/water

This paper reports the spectra of methyl red (MR) in the presence of sodium dioctylsulfosuccinate (AOT) by UV-Vis spectrophotometer at 298.15 +/- 0.1 K. The experiment shows the effect of acetone, AOT and water concentration on methyl red. The spectral study was based on R parameter, which is defined as [H2O]/[AOT]. The spectral study was possible in the range of R = 0-20 only because the solution appeared to be cloudy above this amount of water. When the concentration of AOT increased, the absorption of MR decreased, indicating a hypochromic shift, which is due to the interaction between AOT and MR. The absorbance increases with the increasing value of R, which indicates that the H2O molecule hinders the interactional forces between AOT and MR. The distribution constant was calculated by using nonlinear regression analysis and its variation with different R values indicate the effect of water content in the distribution behavior of MR in between the solvent and micellar region whereas the variation of the binding constant with different R values indicates the affinity of micelles to bind MR molecule. The study of this binding affinity will be very helpful in textile dyeing, decolorization of industrial effluents and development of azo-based molecules in novel photonic and optoelectronic devices. (C) 2021 Elsevier B.V. All rights reserved.