AVS 60th International Symposium and Exhibition
    Ions at Aqueous Interfaces Focus Topic Tuesday Sessions
       Session IA+BA-TuA

Invited Paper IA+BA-TuA1
Selective Adsorption of Ions to Aqueous Interfaces and its Effects on Evaporation Rates

Tuesday, October 29, 2013, 2:00 pm, Room 201 B

Session: Ions and Biomolecules at Aqueous Interfaces
Presenter: R.J. Saykally, University of California, Berkeley
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By exploiting the strong charge-transfer-to-solvent (CTTS) resonances of selected anions in aqueous electrolytes, their interfacial adsorption properties are measured by UV-SHG spectroscopy. Temperature and concentration dependences are determined, with the goal of establishing a complete molecular description of selective ion adsorption. A study of thiocyanate reveals that its strong adsorption is driven by hydration forces and impeded by a novel entropy effect. A study of nitrite indicates adsorption as an ion pair with sodium. Evaporation rates are measured by combining liquid microjet technology and Raman thermometry. The relationship between surface propensities of ions and evaporation rates is investigated. A detailed molecular mechanism for both selective ion adsorption and aqueous evaporation is explored.