2022-01-12
Water-Induced Restructuring of the Surface of a Deep Eutectic Solvent
Publication
Publication
J. Phys. Chem. Lett. , Volume 13 p. 634- 641
We study the molecular-scale structure of the surface of Reline, a DES made from urea and choline chloride, using heterodyne-detected vibrational sum frequency generation (HD-VSFG). Reline absorbs water when exposed to the ambient atmosphere, and following structure-specific changes at the Reline/air interface is crucial and difficult. For Reline (dry, 0 wt %, w/w, water) we observe vibrational signatures of both urea and choline ions at the surface. Upon increase of the water content, there is a gradual depletion of urea from the surface, an enhanced alignment, and an enrichment of the surface with choline cations, indicating surface speciation of ChCl. Above 40% w/w water content, choline cations abruptly deplete from the surface, as evidenced by the decrease of the vibrational signal of the −CH2– groups of choline and the rapid rise of a water signal. Above 60% w/w water content, the surface spectrum of aqueous Reline becomes indistinguishable from that of neat water.
| Additional Metadata | |
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| , | |
| American Chemical Society (ACS), ACS | |
| European Research Council (ERC) , European Union Horizon 2020 | |
| doi.org/10.1021/acs.jpclett.1c03907 | |
| J. Phys. Chem. Lett. | |
| Organisation | Ultrafast Spectroscopy |
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Gera, R., Moll, C., Bhattacherje, A., & Bakker, H. (2022). Water-Induced Restructuring of the Surface of a Deep Eutectic Solvent. J. Phys. Chem. Lett., 13, 634–641. doi:10.1021/acs.jpclett.1c03907 |
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