In the field of industry and particularly energy, liquid water circuits are omnipresent. Fluids, by interacting with pipes made from metal alloys, inevitably lead to the formation of corrosion products.

Predicting the behavior of small particles (order of magnitude of µm) is therefore of particular interest. Indeed, due to their size, the behavior of the latter is governed by forces of electrical origin responsible for their adhesion to the surfaces. The electrokinetic properties and in particular the surface potential thus control the fate of the particle and can be defined using the zeta potential. This quantity characterizes a solid/solution couple and takes into consideration both the particle and its surface chemical properties as well as the solution where the particle is located.

If the characterization of the zeta potential at room temperature is quite widespread, its determination at high temperature is today confined to a few examples (theses by C. Cherpin 2022 [1] and M. Barale 2006 [2], studies of VTT [3] and EDF with the University of Besançon 2002 [4] and the EPRI patent 1994 [5]). The CEA (LC2R) has developed an innovative measurement method currently being patented to explore poorly developed experimental techniques based on theoretical hypotheses to be confirmed.

Through multi-physics (flow, temperature, chemistry, electrochemistry, etc.) and multi-scale (microscopic particles influencing a macroscopic state) approaches, the objective of the thesis is therefore to carry out measurements of the surface properties of particles in water at high temperature depending on the physicochemical conditions (pH, RedOx and temperature), to adapt existing models or propose new ones then validate them with experimental data.
The data thus obtained is intended to feed the simulation codes in order to better understand and control the aging of the circuits.

[1] C. Cherpin, PhD, 2022, Modelling the behaviour of colloidal corrosion products in the primary circuit of Pressurized Water Reactors
[2] M. Barale, PhD, 2006, Etude du comportement des particules colloïdales dans les conditions physico-chimiques du circuit primaire des réacteurs à eau sous pression
[3] E. Velin, Master’s Thesis, 2013, The effect of Temperature on the Zeta Potential of Magnetite Particles in Ammonia, Morpholine and Ethanolamine Solutions