Densities and Viscosities of Amino Acid + Xylitol + Water Solutions at 293.15 ≤ T/K ≤ 323.15

Abstract

Densities (ρ) and viscosities (η) of aqueous xylitol solutions with glycine, l-alanine, l-valine, l-threonine, or l-arginine were measured at T = (293.15 to 323.15) K under atmospheric pressure. The density values were utilized to further calculate the apparent molar volume (V φ), the limiting partial molar volumes of amino acids (V φ 0), the limiting partial molar volumes of transfer (Δtr V φ 0) and the interaction coefficients V ab, V abb, V abbb. The viscosity data were used to obtain viscosity B-coefficient, the free energies of activation per mole of solvent (Δμ1 0≠) and solute (Δμ2 0≠). The limiting partial molar volumes of transfer and the free energies of activation per mole of both solvent (Δμ1 0≠) and solute (Δμ2 0≠) were analyzed based on the cosphere overlap model and transition state theory, respectively. The hydration number of amino acid was determined using the obtained limiting partial molar volume and viscosity B-coefficient.

Measurement of the Density and Ultrasonic Speed of the Sound of Poly(ethylene glycols) (600 and 6000) in Aqueous Vitamin B5 Solutions at Different Temperatures

“… Here, V v.w represents the Vander Waal’s equation volume, V void represents the empty or void volume, and V shrinkage represents the volume due to change in solute–solvent interactions. In water and aqueous d -Panthenol solutions, V v.w and V void are considered to have the same magnitudes; then, the decline in V shrinkage alone contributes to the positive values of Δ V ϕ 0 , implying that on the hydrated poly­(ethylene glycols) there is a dehydration effect due to d -Panthenol. ,,,− …”

Can Jones–Dole’s B-Coefficient be a Consistent Structure-Making/Breaking Marker? Rigorous Molecular-Based Analysis and Critical Assessment of Its Marker Uniqueness

“…Consequently, these criteria cannot be taken as markers of structure-making/breaking trends despite their widespread use in the literature. Notably, despite the lack of an explicit link to any actual microstructural feature of the solutions under study, the structure-making/breaking criterion around the sign of (∂ B /∂ T ) P has been regularly used in combination with, or as a complement to, the isobaric expansivity-based criterion for the structure-making/breaking ability of infinitely dilute solutes, as attested by a representative sample of the relevant literature. − …”

Exploring Diverse Amino Acid-Polyol Interactions Prevailing in Aqueous Systems at Different Temperatures by Physicochemical Contrivance Simultaneously Optimized by DFT

“…Several studies on the interactions between polyhydroxy compounds and amino acids have been published recently. ,− In our present work, we study the intermolecular interaction of two essential amino acids l -valine and L -leucine with a D -mannitol solution with varying mannitol concentrations at five different temperatures and atmospheric pressure and report the density, viscosity, conductance (at different molal concentrations, temperatures, and atmospheric pressure), and surface tension (at room temperature and atmospheric pressure) to supplement and provide some new material property data. To examine the solute–solvent and solute–solute interactions, we estimate the apparent molar volumes, limiting apparent molar volumes, Falkenhagen coefficient, viscosity B coefficient, and temperature derivative of B , Δ H ≠0 , and d B /d T from these experimental data.…”