Densities, Sound Speed, and Viscosities of Some Amino Acids with Aqueous Tetra-Butyl Ammonium Iodide Solutions at Different Temperatures

Abstract

Apparent molar volumes (V⌀), apparent molar isentropic compression (K⌀,s), and viscosity B coefficient of glycine, l-alanine, and l-valine in (0.01 and 0.03) mol·kg–1 aqueous tetrabutyl ammonium iodide (TBAI) solutions have been determined at temperatures (288.15, 293.15, 298.15, 303.15, and 308.15) K from their experimental density, ultrasonic speed, and flow time measurements, respectively. Partial molar volumes (V⌀0) and partial molar isentropic compression (K⌀,s0) have been determined from the above measurements. Further, these data were used to calculate the corresponding transfer parameters (ΔV⌀,s0 and ΔK⌀,s0), hydration number (nH), side chain group contributions of V⌀0, and viscosity B coefficients of the amino acids, partial molar expansibilities (E⌀0), (dB/dT), and related parameters. The trends of variations of experimental and computed parameters have been discussed in terms of solute–solvent interactions with an emphasis on structure-making and structure-breaking ability of the above amino ac...