TY - JOUR
T1 - Characterizing Anion Adsorption to Aqueous Interfaces: Toluene-Water versus Air-Water
AU - Devlin, Shane W.
AU - McCaffrey, Debra L.
AU - Saykally, Richard J.
N1 - KAUST Repository Item: Exported on 2022-05-25
Acknowledged KAUST grant number(s): OSR-2019-CPF-4109.3
Acknowledgements: This work was supported by the Department of Energy, Office of Basic Energy Sciences, through the Chemical Sciences Division at the Lawrence Berkeley National Laboratory under contract #CH403503, through King Abdullah University of Science and Technology (KAUST) under contract #OSR-2019-CPF-4109.3, and through the ACS Petroleum Research Fund under grant #59408-ND6
This publication acknowledges KAUST support, but has no KAUST affiliated authors.
PY - 2021/12/30
Y1 - 2021/12/30
N2 - We continue our investigation of the behavior of simple ions at aqueous interfaces, employing the combination of two surface-sensitive nonlinear spectroscopy tools, broadband deep UV electronic sum-frequency generation and UV second harmonic generation, to characterize the adsorption of thiocyanate to the interface of water with toluene─a prototypical hydrophobe. We find that both the interfacial spectrum and the Gibbs free energy of adsorption closely match results previously reported for the air-water interface. We observe no relative spectral shift in the higher-energy CTTS transition of thiocyanate, implying similar solvation environments for the two interfaces. Similarly, the Gibbs free energies of adsorption agree within error; however, we expect the respective enthalpic and entropic contributions to differ between the two interfaces, similar to our earlier findings for the air-water versus graphene-water interfaces. Further experiments and theoretical modeling are necessary to quantify the mechanistic differences.
AB - We continue our investigation of the behavior of simple ions at aqueous interfaces, employing the combination of two surface-sensitive nonlinear spectroscopy tools, broadband deep UV electronic sum-frequency generation and UV second harmonic generation, to characterize the adsorption of thiocyanate to the interface of water with toluene─a prototypical hydrophobe. We find that both the interfacial spectrum and the Gibbs free energy of adsorption closely match results previously reported for the air-water interface. We observe no relative spectral shift in the higher-energy CTTS transition of thiocyanate, implying similar solvation environments for the two interfaces. Similarly, the Gibbs free energies of adsorption agree within error; however, we expect the respective enthalpic and entropic contributions to differ between the two interfaces, similar to our earlier findings for the air-water versus graphene-water interfaces. Further experiments and theoretical modeling are necessary to quantify the mechanistic differences.
UR - http://hdl.handle.net/10754/678204
UR - https://pubs.acs.org/doi/10.1021/acs.jpclett.1c03816
UR - http://www.scopus.com/inward/record.url?scp=85122725544&partnerID=8YFLogxK
U2 - 10.1021/acs.jpclett.1c03816
DO - 10.1021/acs.jpclett.1c03816
M3 - Article
C2 - 34967638
SN - 1948-7185
VL - 13
SP - 222
EP - 228
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
IS - 1
ER -