Analysis of molecular interactions of an aqueous benzoates with glycolic and lactic acid: spectroscopic, acoustic, and volumetric approach

Abstract

Volumetric as well as Acoustic properties for the ternary liquid combination (water + sodium methyl p-hydroxybenzoate + glycolic acid/lactic acid) are evaluated at several temperatures using a Densimeter (DSA 5000 M) over the range of concentrations (0.000, 0.015, 0.025, 0.035) mol.kg-1. Several thermo-acoustical properties were computed utilizing the experimental data. These values were then used to derive several parameters, including the apparent molar volume(V∅ ); partial molar volume(V∅0); apparent molar isentropic compression(K∅,S); transfer properties(ΔV∅0,ΔK∅,s0); partial molar isentropic compression(K∅,s0); apparent molar expansibility (E∅0) as well as its first derivative (∂Eϕ0/∂T)P; and coefficient of thermal expansivity(αp). The obtained results are explained by analyzing the several interactions that take place inside the liquid system by implementing the theory of co-sphere overlap. Utilizing these thermodynamical parameters, the interaction coefficients are computed to evaluate the ternary mixture corresponding to the interactions between solutes and solvents. FTIR spectrum analysis revealed the presence of H-bonds along with the other molecular interactions in the analyzed systems, as shown by the shifting of the O-H stretching band.