Surfactant - Alcohol interactions: An ultrasonic, UV and FTIR analysis

The study focuses on the density, viscosity and ultrasonic velocity of non-ionic surfactant sorbitan sesquioleate with alcohols. Sorbitan sesquioleate dissolves in water-anisyl alcohol, water-benzyl alcohol and water-cinnamyl alcohol. Different concentrations of these mixtures are determined in order to view the Critical Micelle Concentration (CMC). To study the molecular interaction of the mixture of surfactant and alcohols, various acoustical parameters such as adiabatic compressibility (beta), intermolecular free length (L-f), internal pressure (pi(i)), Rao's constant (R-a), absorption coefficient (alpha/f(2)), free volume (V-f), cohesive energy (CE), relaxation time (tau), acoustical impedance (Z(a)) and solvation number (S-n) have been calculated. The trends in the variation of these parameters are used to discuss the molecular interactions present among the mixtures. UV and FTIR analysis confirm this interaction of the mixture of surfactant and alcohols.