Régine Perzynski

Régine Perzynski

Professeur - Université P. et M. Curie
Laboratoire PHENIX, UMR 8234
Sorbonne Univ. – Paris

Title: Colloidal Structure and Thermo-Diffusion of Magnetic-Nanoparticle Dispersions in Ionic Liquids


Magnetic nanoparticles (NPs) bearing a superficial electrostatic charge can be
dispersed in various polar media but also more complex ones such as Room Temperature
Ionic Liquids (ILs) only constituted of ions, which are liquid at room temperature [13]. This
class of solvents is interesting due to their very low volatility, versatility, large electrochemical
domain, wide temperature range. They could be operational up to a few 100°C [4], in
particular for thermoelectric applications [57].
Stable colloidal NP’s dispersions in ILs are obtained at various concentrations (c) and
temperatures (T). A welladapted NP’s coating is necessary, chosen and controlled during
the preparation through key parameters. Two kinds of interactions are of paramount
importance, namely the interaction NP/solvent and the NP/NP interaction.
The colloidal stability and the NP/NP interaction are probed by Small Angle Scattering of x
rays and/or neutrons. The parameters of NP/solvent interaction are provided by the evolution
of thermodiffusion with c and T by Forced Rayleigh Scattering [8], where applying Tgradients
at the microscale produces cgradients thanks to Soret effect.

This work has been supported by the Brazilian agency CNPq, the bilateral program CAPES
COFECUB n° Ph 959/20 and the European Union’s Horizon 2020 research and innovation
programme under grant agreement no 731976 (MAGENTA).

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[4] Fiuza T. et al, Soft Matter 17, 4566 4577 (2021).
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[6] Salez T.J. et al, Phys. Chem. Chem. Phys. 19, 94099416 (2017)
[7] Battacharya K. et al, Chemical Engineering 4, 125 (2020)
[8] Sarkar M. et al, Eur. Phys. J E 42 , 72 110 (2019)