Long-timescale molecular simulations: from cement to supercapacitors

DIPC Seminars

Speaker

Romain Dupuis
LMGC, CNRS, Montpellier University

When

2025/09/17
12:00

Place

DIPC Josebe Olarra Seminar Room

Host

Andrés Ayuela

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Molecular dynamics simulations have emerged as a powerful tool for probing the atomic-scale behavior of complex materials under realistic conditions. For simulating large systems without disregarding the chemical reactions essential for phase transformations, we use reactive force fields such as ReaxFF. Coupling it with enhanced sampling approaches, such as parallel tempering and metadynamics, we investigate the formation of silicate networks in cement
and geopolymers, as well as the leaching of Ca2+ and its reaction with CO2 in cement pores[1, 2, 3]. By capturing the evolution of atomic interactions, we elucidate the mechanisms governing hydration[1], polymerization[2, 3], and ion transport[2], processes critical for mechanical, chemical, and electrochemical performance. Moreover, we have recently developed a workflow to apply voltage on porous carbon electrodes in atomistic simulations with chemical reactivity, enabling the study of ion adsorption in supercapacitors and other capacitive systems such as desalination[4, 5, 6]. This approach provides important insights into the electrochemical behavior of nanoporous carbon electrodes under polarization, revealing pore-scale textural changes and ion docking mechanisms[6]. We show the importance of taking into account the molecular flexibility of the electrodes. We also explore the adsorption of pollutants such as per/poly-fluoroalkyl substances (PFAS) in porous carbon and organic porous networks. Most recently, we started developing machine learning potentials to model H2 adsorption and diffusion in metal-organic frameworks with open metal sites, enabling accurate predictions of gas storage performance[8]. We are now extending this framework to study the adsorption and removal of PFAS, further expanding the applicability of our simulations to environmental remediation.

[1] Zhu, X., et al. (2024). Collective molecular-scale carbonation path in aqueous solutions with sufficient structural sampling: From CO2 to CaCO3. The Journal of Chemical Physics, 161(18).
[2] Dupuis, R., et al. (2022). Alkali silica reaction: A view from the nanoscale. Cement and Concrete Research, 152, 106652.
[3] Dupuis, R., et al. (2020). Time resolved alkali silicate decondensation by sodium hydroxide solution. Journal of Physics: Materials, 3(1), 014012.
[4] Florent, M., et al. (2025). Insight into the effect of electrolyte ions docked in subnanopores of metal-free carbon cathode on the ORR activity. Carbon, 239, 120324.
[5] Dupuis, R., et al. (2022). How chemical defects influence the charging of nanoporous carbon supercapacitors. PNAS, 119(17), e2121945119.
[6] Dupuis, R., et al. (2025). Pore-Scale Textural Changes upon Ion Adsorption in Voltage-Polarized Nanoporous Carbon Electrodes. PRX Energy, 4(2), 023001.
[7] Quílez-Bermejo, J., et al. (2025). Ion docking drives HER carbon-based electrocatalyst performance. Carbon, 120383.
[8] Liu, S., Dupuis, R., et al. (2024). Machine learning potential for modelling H2 adsorption/diffusion in MOFs with open metal sites. Chemical Science, 15(14), 5294-5302.