Volumetric and compressibility studies and phase equilibria of aqueous biphasic systems of alcohols using phase diagram

Abstract

The solubility data of Na 2 S 2 O 3 ·5H 2 O in various concentrations of water and ethanol/1-propanol/2-propanol/2-methyl-2-propanol have been obtained to plot triangular phase diagrams and to determine the liquid-liquid-solid equilibria at 298.15 K. The density and sound velocity measurements were carried out for binary systems (water-salt, water-ethanol/1propanol/2-propanol/2-methyl-2-propanol) and ternary systems (water-ethanol/1-propanol/2-propanol/2-methyl-2-propanol-Na 2 S 2 O 3 ) to investigate volumetric and compressibility properties. The obtained data was used to determine the acoustic parameters including adiabatic compressibility (β s ), excess molar volume (V E ), intermolecular free length (L f ), specific acoustic impedance (Z), relative association (R A ), solvation number (S n ) of water-alcohols, water-salt and water-alcohol-salt at 298.15 ± 0.05 K to evaluate equilibrium effects. Based on which, the salting-out of studied alcohols and phase forming ability of Na 2 S 2 O 3 through its bond making and breaking properties, intermolecular interactions were reported. The density, sound velocity and adiabatic compressibility of ternary system suggest phase separation phenomenon is bond breaking and bond making process with hydrogen bonding and hydrophobic interaction. The phase formation ability of systems composed of different alcohols is in order of 2-methyl-2-propanol > 1-propanol > 2-propanol > ethanol.

Acoustic assessment in binary mixtures of a polar nuclear extractant, DEHPA with eight non polar diluents at 303.15K – a comparative study

“…This indicates solute-solvent interaction due to formation of aggregates of solvent molecules around DEHPA, in the binary systems. This corroborates dipole-induced dipole interaction, owing to the closer packing of the molecules [27]. The result of the excess properties of the ultrasonic parameters shows a different trend in these non-polar liquids.…”

Synergistically enhancing hydrogen bonding, hydrophobic interaction and electrostatic association of collagen fiber to flavonoid aglycones for their effective separation by polyethyleneimine modification

“…The phenol hydroxyls also give flavonoids weak acidity, and thus the electrostatic interaction was thought to be another interaction between PEI-CF and flavonoids. In order to investigate the adsorption mechanism, the effects of urea, n-propanol and NaCl, used as breaking agents of hydrogen bonding [28], hydrophobic interaction [29] and electrostatic association [30], on adsorption extents of PEI-CF-10 to quercetin were investigated in pure ethanol, 80% and 40% aqueous ethanol solutions, and shown in Fig. 6a-c.…”

Optical quantification of molecular interaction strength in protein condensates

“…While the application of Brillouin microscopy for biophysical research is a relatively recent development [18, 20], the investigation of viscoelasticity with sound waves has a long history. Ultrasonic investigations were used broadly in material science and polymer physics, as well as to study phase separation [21, 22]. One specific advantage of using a sound-based method to study protein condensates is the possibility to quantitatively characterize material properties in any state of matter.…”