Studies on the interactions of diglycine and triglycine with polyethylene glycol 400 in aqueous solutions by density and ultrasound speed measurements

ŞAHİN M., Ayranci E.

JOURNAL OF CHEMICAL THERMODYNAMICS, vol.58, pp.70-82, 2013 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 58
  • Publication Date: 2013
  • Doi Number: 10.1016/j.jct.2012.10.018
  • Journal Name: JOURNAL OF CHEMICAL THERMODYNAMICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.70-82
  • Keywords: Apparent molar volume, Apparent molar isentropic compression, Diglycine, Triglycine, Polyethylene glycol, Density, PARTIAL MOLAR VOLUMES, AMINO-ACIDS, ADIABATIC COMPRESSIBILITIES, HEAT-CAPACITIES, 298.15 K, THERMODYNAMIC PROPERTIES, PEPTIDE SOLUTIONS, SODIUM-CHLORIDE, NACL SOLUTIONS, WATER
  • Akdeniz University Affiliated: Yes

Abstract

Density and ultrasound speed were measured accurately for diglycine + water, triglycine + water, diglycine + water-polyethylene glycol 400 (PEG400) and triglycine + water-PEG400 solutions at T = (293.15, 298.15, 303.15 and 308.15) K. The results were used in evaluating thermodynamic properties as apparent molar volumes (V-empty set) and apparent molar isentropic compressions (K-S Phi) of diglycine and triglycine in water and in PEG400 solutions. Infinite dilution values of these parameters, V-empty set(o), and K-S Phi(o), were obtained from their plots as a function of molality by extrapolation and have been utilized in obtaining transfer volumes and transfer compressions at infinite dilution. All transfer volumes and transfer compressions were found to increase with increasing molality of PEG400. Apparent molar isobaric expansions were derived from the temperature dependence of V-empty set values at infinite dilution and at finite concentrations. All the results were interpreted in terms of solute (diglycine or triglycine) and co-solute (PEG400) and solvent (H2O) interactions. (c) 2012 Elsevier Ltd. All rights reserved.