Sound Speed and Density Studies of Interactions Between Cationic Surfactants and Aqueous Gelatin Solution

Abstract

Studies on the interactions of surfactants with proteins can contribute to an understanding of the action of surfactants as denaturants and as solubilizing agents for membranes of proteins and lipids. Quantitative aspects of such studies may include direct measurements of properties, such as viscosity, density, sound speed, conductance, and elucidation of the often highly complex phase diagrams. In this study, sound speed and density studies of surfactants, viz., cetyltrimethyl ammonium bromide, cetyltrimethyl ammonium chloride, and di(dodecydimethyl ammonium bromide) (12-2-12) have been carried out in a 0.02 % w/v aqueous solution of gelatin at temperatures of 20 • C, 25 • C, 30 • C, and 35 • C. From the measured data, the parameters apparent molar volumes (φ v ), adiabatic compressibility (β), and apparent molar compressibility (φ k ) have been calculated to interpret the protein-surfactant interactions. The variations in these parameters with the concentration of the surfactant suggests the manifestation of hydrophobic interactions in the system.

Apparent molar volume and ultrasonic studies on some bile salts in water–aprotic solvent mixtures

“…This may be attributed to the presence of hydrophobic surface at the convex side (␤-side) and a hydrophilic surface consisting of hydroxyl and carboxylate groups at the concave side (␣-side) of the steroid nucleus, respectively. A similar results of small and negative values for apparent molar volumes have been reported by Chauhan et al [18] in di(dodecyldimethyl ammonium bromide) (DDAB) in aqueous gelatin solutions, where this exceptional behaviour has been explained as due to the presence of a relatively larger hydrophobic group in DDAB. Moreover, the negative values of apparent molar volumes of bile salts in water and in water-10% (v/v) of aprotic solvent mixtures indicate that dipole-dipole interaction between solute and solvent molecules is appreciable.…”

A Comparative Study of Micellization Behavior of an Ethoxylated Alkylphenol in Aqueous Solutions of Glycine and Leucine

“…In continuation of our interest in surfactant systems [1][2][3][4][5][6], we have studied in detail the effect of two amino acids, viz. glycine and leucine, in terms of physicochemical properties, on the micellization behavior of a nonionic surfactant, i.e.…”

“…The physicochemical properties of a surfactant are affected by the presence of co-solute/solvent and provide a valuable tool to investigate structural changes in these solutions [9]. The sound velocity data have enabled us to provide significant information about the nature and relative strength of various types of inter-ionic or intermolecular interactions between the components [5,6]. Therefore, various derived parameters such as isentropic compressibility (j s ), apparent molar volume (/ v ), apparent molar adiabatic compression (/ j ), etc.…”

Gatifloxacin–Ionic Surfactant Interactions: Volumetric, Acoustic, Voltammetric, and Spectroscopic Studies

“…Densities and sound velocities for DTAB and SDS in PBS (pH 7.4) in the absence and presence of GTF (2.56 × 10 −4 mol kg −1 ) as a function of surfactant molalities and temperature are summarized in Supporting Information, Tables S1–S4. The apparent molar volume ( ɸ V ) of DTAB and SDS was determined using the following relation (Chauhan et al, 2012): …”