Preventing iron( II ) precipitation in aqueous systems using polyacrylic acid some molecular insights

Pierre-Arnaud Artola (1) , Bernard Rousseau (1) , Carine Clavaguera (1) , Marion Roy (2, 3) , Dominique You (2, 3) , Gabriel Plancque (2, 3)

1 LCPO - Laboratoire de Chimie Physique D'Orsay
2 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)
3 SECR - Service d'Etudes du Comportement des Radionucléides

We present molecular dynamics simulations of aqueous iron(II) systems in the presence of polyacrylic acid (PAA) under the extreme conditions that take place in the secondary coolant circuit of a nuclear power plant. The aim of this work is to understand how the oligomer can prevent iron(II) deposits, and to provide molecular interpretation. We show how, to this end, not only the complexant ability is necessary, but also the chain length compared to iron(II) concentration. When the chain is long enough, a hyper-complexation phenomenon occurs that can explain the specific capacity of the polymer to prevent iron(II) precipitation.

Keywords: Molecular Dynamics; water; iron; polyacrylic acid; secondary circuit; complex; dispersant; Pressurized Water Reactor

Domains: Nuclear Experiment [nucl-ex]; Nuclear Theory [nucl-th]

Pierre-Arnaud Artola, Bernard Rousseau, Carine Clavaguera, Marion Roy, Dominique You, et al.. Preventing iron( II ) precipitation in aqueous systems using polyacrylic acid some molecular insights. Physical Chemistry Chemical Physics, 2018, 20, pp.18056-18065. ⟨10.1039/c7cp02743e⟩. ⟨cea-02418710⟩