Na+ and K+ Segregation between Liquid Water and Water Absorbed in Silica Gel

✍ Scribed by G.F. Cerofolini; G. Boara

• Book ID: 102577727
• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 330 KB
• Volume: 161
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1993.1461

✦ Synopsis

The segregation of (\mathrm{Na}^{+})and (\mathrm{K}^{+})between liquid water and water absorbed in (\mathrm{SiO}{2}) gel is experimentally studied by the addition of a wanted amount of highly porous (\mathrm{SiO}{2}) to water solutions of (\mathrm{NaCl}) and (\mathrm{KCl}). This study shows that in the high dilution limit (\mathrm{K}^{+})segregates preferentially in absorbed water, while (\mathrm{Na}^{+})docs not. This specificity is ascribed to the different hydration energies and is lost at high concentrations where other factors (the raise of a negative surface clectrostatic potential) facilitate segregation in alsorbed water. The cosegregation of (\mathrm{K}^{\prime}) and (\mathrm{Na}^{+})shows the simulancous accumulation of (\mathrm{K}^{+})and depletion of (\mathrm{Na}^{+}), in strict analogy with biological systems. (1993 Academic Press, Inc.