Viscometric and Densiometric Investigation of Water–Polyethylene Glycol–KCl, KBr, KI Systems

• Published in: Russian Journal of Physical Chemistry A 2022-10, Vol.96 (10), p.2082-2087
• Main Authors: Pashaev, B. G., Rajabov, M. R.
• Format: Article
• Language: English
• Subjects: Chemical Thermodynamics and Thermochemistry; Chemistry; Chemistry and Materials Science; Enthalpy; Entropy of activation; Hydration; Mathematical analysis; Molar volume; Molecular weight; Parameters; Physical Chemistry; Polyethylene glycol; Temperature; Viscous flow
• ISSN: 0036-0244; 1531-863X
• DOI: 10.1134/S0036024422090254

The dynamic viscosity and density of the water–polyethylene glycol (PEG), water–PE–KCl, water–PEG–KBr, and water–PEG–KI systems are measured in the 293.15–323.15 K range of temperatures with PEG mole fractions of 0–0.001. PEG fractions with average molecular weights M PEG = 3000 and 6000 g/mol are considered. The concentration of salts (KCl, KBr, KI) in water–PEG–KCl, water–PEG–KBr, and water–PEG–KI systems is 0.01 mole fractions. The parameters (Gibbs energy, enthalpy, and entropy) of viscous flow activation and the partial molar volumes of PEG in solutions are calculated using experimental data in the specified range of temperatures and concentrations in the system. It was found that the parameters of viscous flow activation grow along with the concentrations while the partial molar volume of PEG in a solution falls. A simple way of determining the hydration number of a polymer macromolecule is described, and the hydration number of a PEG macromolecule in a solution is calculated. It is found that the hydration number of a PEG macromolecule falls as the temperature rises and grows along with the molecular weight.