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Updated: May 28, 2026

Surface Properties of Synthesized Nanoporous Carbon and Silica Matrices
Published on: March 27, 2019
Changes in apparent molar water volume and DKP solubility yield insights on the Hofmeister effect
Alexander Y Payumo1, R Michael Huijon, Deauna D Mansfield
1Department of Chemistry, San José State University, San José, California 95192-0101, United States.
Abstract:
This study examines the properties of a 4 × 2 matrix of aqueous cations and anions at concentrations up to 8.0 M. The apparent molar water volume, as calculated by subtracting the mass and volume of the ions from the corresponding solution density, was found to exceed the molar volume of ice in many concentrated electrolyte solutions, underscoring the nonideal behavior of these systems. The solvent properties of water were also analyzed by measuring the solubility of diketopiperazine (DKP) in 2.000 M salt solutions prepared from the same ion combinations. Solution rankings for DKP solubility were found to parallel the Hofmeister series for both cations and anions, whereas molar water volume concurred with the cation series only. The results are discussed within the framework of a desolvation energy model that attributes solute-specific changes in equilibria to solute-dependent changes in the free energy of bulk water.
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