Investigations on thermophysical properties of glycine and glycylglycine in aqueous betaine hydrochloride solutions at different temperatures

Density (ρ), ultrasonic velocity (u) and viscosity (η) for an amino acid (glycine) and a dipeptide (glycylglycine) in aqueous and (0.1, 0.2 and 0.3) mol kg−1 binary aqueous betaine hydrochloride media at six different temperatures, T = (293.15–318.15) K and under atmospheric pressure (0.1 MPa) have been determined. Various volumetric, compressibility and rheological parameters such as apparent molar parameters (Vϕ, Kϕ,s), partial molar parameters (V0ϕ, K0ϕ,s), transfer parameters (V0ϕ,tr,K0ϕ,s,tr,Btr) viscosity coefficients (A and B), hydration number (nH) etc. have been computed from the experimentally measured data. The structure breaking ability of each solute has been examined through the negative sign of Hepler's constant (∂E0ϕ/∂T)p values and a positive sign of dBdT (temperature derivative of B-coefficient) values. Moreover, the cosphere overlap model has been employed for the comprehension of different sorts of intermolecular interactions predominating in the studied ternary solutions.