Analysing the molecular interactions of ternary (lactose plus water plus tributylmethylammonium chloride) solutions at different temperatures via physicochemical methods

The interactions of lactose with tributylmethylammonium chloride (Bu3MeNCl) as the function of temperature have been studied by amalgamation of volumetric, acoustic and viscometric methods. Density, ultrasonic speed, and viscosity for varying concentrations of lactose in water and in (0.020, 0.039, 0.059, 0.079) mol.kg(-1) aqueous solutions of Bu3MeNCl have been determined at five distinct temperatures (T = 293.15-313.15) K. These experimental values have been used to calculate apparent molar volume, V-phi, limiting apparent molar volume, V-phi(0), apparent molar isentropic compression, K-phi,K-s, limiting apparent molar isentropic compression, K-phi,s(0), viscosity B-coefficient, their transfer values, pair and triplet interaction coefficients, and hydration number n(H). The Gibbs free energy of activation for solvent (Delta mu(0#)(1)) and Gibbs free energy of activation for lactose (Delta mu(0#)(2)) in water and in aqueous solutions of Bu3MeNCl have also been assessed and the obtained results support the outcome of volumetric, acoustic and viscometric parameters. These parameters provide better understanding of molecular interactions like solute-solute, solute-solvent interactions present in the systems. Further, it helps in determining structural and functional properties of studied systems and acquired results revealed that the solutions are characterized predominantly by solute-solvent interactions. Also, the values of second derivative of limiting apparent molar volume with respect to temperature indicated that the lactose monohydrate behaves as a structure maker in aqueous tributylmethylammonium chloride solutions. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

The interactions of lactose with tributylmethylammonium chloride were studied at different temperatures. Various parameters such as density, ultrasonic speed, and viscosity were determined to understand the molecular interactions in the system. The results indicated that solute-solvent interactions played a significant role, and lactose monohydrate behaved as a structure maker in the aqueous tributylmethylammonium chloride solutions.