TY  - JOUR
AU  - Lee, Namkyu
AU  - Mohanakumar, Shilpa
AU  - Briels, Willem
AU  - Wiegand, Simone
TI  - Non-monotonic Soret coefficients of aqueous LiCl solutions with varying concentrations
JO  - Physical chemistry, chemical physics
VL  - 26
IS  - 9
SN  - 1463-9076
CY  - Cambridge
PB  - RSC Publ.
M1  - FZJ-2024-01765
SP  - 7830 - 7836
PY  - 2024
N1  - data can be found at 10.5281/zenodo.10666454
AB  - We investigate the thermodiffusive properties of aqueous solutions of lithium chloride, using thermal diffusion forced Rayleigh scattering in a concentration range of 0.5 – 2 mole per kg of solvent and a temperature range of 5 to 45°C. All solutions exhibit non-monotonic variations of the Soret coefficient S_T with concentration exhibiting a minimum at about one mole per kg of solvent. The depth of the minimum decreases with increasing temperature and shifts slightly towards higher concentrations. We compare the experimental data with published data and apply a recent model based on overlapping hydration shells. Additionally, we calculate the ratio of the phenomenological Onsager coefficients L_{1q}'/{L_{11} using our experimental results and published data to calculate the thermodynamic factor. Simple linear, quadratic and exponential functions can be used to describe this ratio accurately and together with the thermodynamic factors the experimental Soret coefficients can be reproduced. The main conclusion from this analysis is that the minimum in the Soret coefficients results from a maximum in the thermodynamic factor, which appears itself at concentrations far below the experimental concentrations. Only after multiplication with the (negative) monotonous Onsager ratio does the minimum move into the experimental concentration window.
LB  - PUB:(DE-HGF)16
C6  - 38375894
UR  - <Go to ISI:>//WOS:001166404200001
DO  - DOI:10.1039/D3CP06061F
UR  - https://juser.fz-juelich.de/record/1023708
ER  -