Abstract
The spectroscopy and dynamics of water/methanol (MeOH) mixtures at hydroxylated silica surfaces is investigated from atomistic simulations. The particular focus is on how the structural dynamics of MeOH changes when comparing surface-bound and MeOH in the bulk. From analyzing the frequency frequency correlation functions it is found that the dynamics on the picosecond time scale differs by almost a factor of two. While the relaxation time is 2.0 ps for MeOH in the bulk solvent it is considerably slowed-down to 3.5 ps for surface-bound MeOH. Surface-adsorbed MeOH molecules reside there for several nanoseconds and their H-bonds are strongly oriented towards the surface-OH groups. These results are of particular relevance for chromatographic systems where the solvent may play a central role in their function. The present simulations suggest that surface-sensitive spectroscopic techniques should be useful in better characterizing such heterogeneous systems and provide detailed insight into solvent dynamics and structure relevant in chromatographic applications.
Original language | English |
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Pages (from-to) | 2938-2944 |
Number of pages | 7 |
Journal | ChemPhysChem |
DOIs | |
State | Published - 19 Sep 2016 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Keywords
- chromatography
- infrared spectroscopy
- molecular dynamics
- silica
- two-dimensional spectroscopy