This title appears in the Scientific Report :
2018
Please use the identifier:
http://dx.doi.org/10.1021/acs.jpcb.8b01152 in citations.
Please use the identifier: http://hdl.handle.net/2128/20301 in citations.
Thermodiffusion of Monovalent Organic Salts in Water
Thermodiffusion of Monovalent Organic Salts in Water
The ionic Soret effect induced by temperaturegradients is investigated in organic electrolytes (tetramethylammoniumand tetrabutylammonium hydroxides) dispersed in waterusing a holographic grating experiment. We report the influences oftemperature and salt concentrations on the Soret, diffusion, andt...
Saved in:
Personal Name(s): | Sehnem, André Luiz |
---|---|
Niether, Doreen / Wiegand, Simone / Figueiredo Neto, Antônio Martins (Corresponding author) | |
Contributing Institute: |
Weiche Materie; ICS-3 |
Published in: |
The @journal of physical chemistry |
Imprint: |
Washington, DC
Soc.
2018
|
DOI: |
10.1021/acs.jpcb.8b01152 |
PubMed ID: |
29558136 |
Document Type: |
Journal Article |
Research Program: |
Functional Macromolecules and Complexes |
Link: |
Restricted Restricted Published on 2018-03-20. Available in OpenAccess from 2019-03-20. |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/20301 in citations.
The ionic Soret effect induced by temperaturegradients is investigated in organic electrolytes (tetramethylammoniumand tetrabutylammonium hydroxides) dispersed in waterusing a holographic grating experiment. We report the influences oftemperature and salt concentrations on the Soret, diffusion, andthermal diffusion coefficients. Experimental results to the thermaldiffusion coefficient are compared with a theoretical description forthermodiffusion of Brownian particles in liquids based in thethermal expansion of the liquid solution. It is observed that theobtained thermal diffusion coefficients for the organic electrolytespresent a similar temperature dependence as the theoretical prediction. Comparing the experimental results for the organic andcommon inorganic salts it is proposed an additional physical mechanism as the cause to the different thermal diffusioncoefficients in both types of salt. We propose that the temperature dependence of hydration free energy gives rise to a force termthat also leads to ion migration in a temperature gradient. We describe the thermal diffusion results as a competition betweenthermal expansion and hydration effects. The specific structure each type of ion cause in water molecules is considered in the heatof transport theory to describe thermal diffusion of electrolytes. A qualitative agreement is seen between our results and theclassical heat of transport theory. |