je5b00941_si_001.pdf (691.41 kB)
Volumetric Properties and Viscosity B-Coefficients for the Ternary Systems Epigallocatechin Gallate + MCl + H2O (M = Li, Na, K) at Temperatures 288.15–308.15 K
journal contribution
posted on 2016-03-29, 18:50 authored by Dawei Li, Guangqian Li, Pingfeng Bian, Zhe Shen, Mengfan Fu, Wenjun Fang, Weidong YanEpigallocatechin
gallate (EGCG) is the most abundant and active components in tea.
In this text, the density and viscosity of ternary aqueous solution
of EGCG containing LiCl/NaCl/KCl were determined at temperatures ranging
from 288.15 to 308.15 K at atmospheric pressure. The density data
was used to compute the apparent molar volumes (Vφ), limiting partial molar volumes (Vφ0),
and transfer partial molar volumes (ΔtrsVφ0).
The viscosity B-Coefficients were calculated from
the measured viscosity data using the extended Jones–Dole equation.
The values of density and viscosity increased continuously with the
increasing of molality of EGCG and decreased with the temperature
increasing. The positive values including (Vφ, Vφ0, ΔtrsVφ0, viscosity B-Coefficients, the free energies of activation for solvent
Δμ10≠, and for solute Δμ20≠) and Helper’s constant (∂2Vφ0/∂T2)p close to zero indicated the presence of strong solute–solvent
interactions and the structure–making effect of EGCG in the
investigated solutions. The apparent molar isobaric expansions (Eφ0) decreasing with temperature suggested that the solute–solvent
interactions became weaker as temperature increased. These significant
parameters could provide necessary data about molecular interactions
occurring in simulated body fluids.