HCl, KCl and KOH solvation resolved solute-solvent interactions and solution surface stress
Sun, Chang Qing
Date of Issue2017
School of Electrical and Electronic Engineering
An incorporation of the hydrogen bond (O:HO or HB) cooperativity notion, contact angle detection, and the differential phonon spectrometrics (DPS) has enabled us to gain refined information on the HCl, KCl and KOH solvation resolved solute-solvent molecular interactions and the solution surface stresses. Results show that ionic polarization stiffens the solvent HO bond phonon from 3200 to 3480 cm−1 in the hydration shells. The HO− in alkaline solution, however, shares not only the same HO phonon redshift of compressed water from 3200 to < 3100 cm−1 but also the dangling bonds of H2O surface featured at 3610 cm−1. Salt and alkaline solvation enhances the solution surface stress by K+ and Cl− ionic polarization. The excessive H+ proton in acid solution forms a H↔H anti-HB that depresses the solution surface stress, instead. The solute capability of transforming the fraction of the O:HO bonds of the solvent matrix is featured by: fH = 0 and fx ∝ 1-exp(-C/C0) (x = HO−, K+ and Cl−) towards saturation. Exercises not only confirm the presence of the H↔H anti-HB point fragilization, the O:⇔:O super-HB point compression, and ionic polarization dominating the performance of the respective HCl, KOH, and KCl solutions, but also demonstrate the power of the DPS that enables high resolution of solute-solute-solvent interactions and correlation between HB relaxation and solution surface stress.
Applied Surface Science
© 2017 Elsevier B.V. This is the author created version of a work that has been peer reviewed and accepted for publication by Applied Surface Science, Elsevier B.V. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1016/j.apsusc.2017.06.019].