Effects of different solutes on the physical chemical properties of aqueous solutions via rearrangement of hydrogen bonds in water

Hydrogen Bond Arrangement Is Shown to Differ in Coexisting Phases of Aqueous Two-Phase Systems

“…where Ij 3080 , Ij 3230 , and Ij 3400 are contributions of the Gaussian components I (3080 cm −1 ), II (3230 cm −1 ), and III (3400 cm −1 ), respectively-component IV (3550 cm −1 ) changes only insignificantly for all compounds studied; k0 and kj are coefficients; and the subscript j denotes the polymer examined. Various solvent features of aqueous solutions of different individual compounds (except some inorganic salts) may be described by the contributions of Gaussian curves III and/or IV [34]. Because these Gaussian components represent the least ice-like water structures, we conjecture that they are probably responsible for the solvent properties of aqueous solutions and phases of ATPSs.…”

“…Details of ATR-FTIR measurements as described in [ 34 ]. ATR-FTIR spectra for each sample were measured in two separately prepared solutions and two aliquots from each phase from each ATPS using a Spectrum Bx FT-IR spectrometer (Perkin-Elmer, Boston, MA, USA) equipped with single reflection Golden Gate diamond ATR (Specac, London, UK).…”

“…We have reported recently [ 34 ] that the hydrogen bond network of water depends on the specific solute. Attenuated total reflection–Fourier transform infrared (ATR-FTIR) spectroscopy was used [ 34 ] to examine the spectra of the OH-stretch band in aqueous solutions of inorganic salts, trimethylamine N-oxide, urea, and the polymers PEG, PVP, and a copolymer of ethylene glycol and propylene glycol (Ucon) at various concentrations.…”

“…We have reported recently [ 34 ] that the hydrogen bond network of water depends on the specific solute. Attenuated total reflection–Fourier transform infrared (ATR-FTIR) spectroscopy was used [ 34 ] to examine the spectra of the OH-stretch band in aqueous solutions of inorganic salts, trimethylamine N-oxide, urea, and the polymers PEG, PVP, and a copolymer of ethylene glycol and propylene glycol (Ucon) at various concentrations. As earlier published [ 34 ], the decomposition of the band into four Gaussian components peaking at 3080, 3230, 3400, and 3550 cm −1 fits, with minimized residuals, every compound examined.…”

“…We suggested [ 34 ] that water includes an ensemble of exactly four different subpopulations of molecules with various hydrogen bond strengths, geometry, and molecular arrangements depending on the solute. Here, we extend this approach to the coexisting phases of several ATPSs.…”