The Effect of Methanol on the Micellar Properties of Dodecyltrimethylammonium Bromide (DTAB) in Aqueous Medium at Different Temperatures

Abstract

The micellar properties of dodecyltrimethylammonium bromide (DTAB) in water and methanol water mixtures at different temperatures have been studied by conductivity and surface tension measurements. The critical micelle concentrations (CMC), degree of ionization (α), standard Gibbs free energy of micellization (), standard enthalpy of micellization (), standard entropy of micellization () and free energy of transfer () were evaluated from conductivity data. The CMC, maximum excess surface concentration ( ), area occupied per surfactant molecule ( ), surface pressure at the CMC ( ), packing parameter (P) and standard free energy interfacial adsorption ) were estimated from surface tension measurements. The CMC of DTAB was found to increase with increasing volume fraction of methanol and increasing temperature. Thermodynamic parameters and surface properties revealed that the addition of methanol changes the relevant physicochemical properties which affect the process of micellization.

The Effect of Polar Head and Chain Length on the Physicochemical Properties of Micellization and Adsorption of Amino Alcohol‐Based Surfactants

“…On the other hand, only a limited number of publications have been devoted to bifunctional species and the effect of the polar head on micellization. The influence of the size of the hydrophilic part of a quaternary ammonium surfactant on its ability to adsorb at the air/water interface and to form micelles in aqueous media has been reported by many researchers (Dahanayake and Rosen, ; Kabir‐ud‐Din et al, ; Moreira and Firoozabadi, ; Omar and Abdel‐Khalek, ; Shah et al, ; Venable and Nauman, ), but the study of the effect of the localization of a polar group with respect to quaternary nitrogen, N + , has not been widely reported. Let us cite, for example, the work of Chevalier et al (), who studied the effect of the distance between the positive group N + and the carboxylate group on the physicochemical parameters, such as the maximum surface excess Γ m and critical micelle concentration (CMC) of zwitterionic surfactants and also the work in which Hajji et al () showed the effect of the polar head of 2‐(decyldimethylammonio) alkanol bromide surfactants on physiochemical parameters such as the degree of ionization, α , and CMC.…”

“…The modification of the molecular structures of the surfactants and the modification of the conditions of the surfactant solution affect the two antagonistic forces, thus influencing the micellization and also the adsorption of the ionic surfactants (Kabir-ud-Din et al, 2008;Moreira and Firoozabadi, 2009;Shah et al, 2016).…”

Effect of Methanol on Viscosity of Aqueous Solutions of Cationic Surfactants at 298.15 to 323.15 K

“…Accurate weight of surfactant with the help of digital high precision electronic balance (accuracy ±0.0001 g) was taken and dissolved in the minimum amount of solvent mixture and was kept overnight for proper dissolution after which the solvent mixture was added to make the desired volume up. The freshly prepared solution was used for the further investigation [8].…”

“…Properties of surfactants are evaluated by the formation of aggregates known as micelle which is affected by different factors such as presence of organic and inorganic additives and temperature. Due to these reasons, micellization of cationic surfactants in binary mixed solvent media has been studied extensively by the researchers [2][3][4][5][6][7][8].…”

Conductivity, Surface Tension, and Comparative Antibacterial Efficacy Study of Different Brands of Soaps of Nepal

“…From the plot of surface tension with the concentration of soap solution, the following surface properties are calculated [35]. e maximum surface excess concentration at the air-water interface Γ max has been calculated by applying Gibbs isotherm:…”