Paris-Saclay University
Biography
I am interested in the dynamics of liquids near solid surfaces. I use molecular dynamics to probe the friction of Lennard-Jones liquids on a model wall as a function of temperature. I also study the slip and friction of polymer solutions on ideal substrate using photobleaching techniques and neutron reflectivity. I am focusing on the dynamics of polymer chains near the wall as the chains are cooled down near their glass transition temperature.
Interests
- Polymer physics
- Rheology
- Molecular Dynamics
- Neutron reflectivity
Education
- Master ICFP in Soft Matter, 2019, Ecole Normale Supérieure de Paris
- Bachelor in fundamental physics, 2017, Ecole Normale Supérieure de Paris
- Classe préparatoire PCSI-PC*, 2013-2016, Lycée Joffre, Montpellier
Material Science – TD L3
Sept 2022 – Jan 2023
Science of measurement – TP IUT 2nd year
IUT Jan 2021 – Jun 2022
Introduction to Python language – TD/TP L1
Paris Diderot University Sept 2020 – Dec 2020
Slip of polymer solutions: effect of temperature
Using a home-made velocimetry technique, we quantify the friction between polymer solutions and solid surfaces as a function of temperature. Coupling our measurements with bulk rheology, we can extract a lot of information about local friction between polymer chains and the wall.
Friction of a Kob-Andersen fluid
We use Molecular Dynamics simulations to study the role of temperature on the friction at the liquid/solid interface with a model system. In particular, we show that at high temperatures, both the viscosity and friction are well-described by activated processes while in the supercooled regime, there is a strong deviation from the usual Arrhenian law, leading to giant slip lengths.
Depletion and adsorption in polymer solutions probed by neutron reflectivity
We use neutron reflectivity to probe the interface between polymer solutions and solid substrates. We observe and quantify a depletion of polymer near the solid substrate. Interestingly, we show that depletion does not prevent adsorption of polymer chains on the wall.
- “Simultaneous depletion and adsorption in polymer solutions near a solid wall”, S. Lafon, T. Outerelo-Corvo, M. Grzelka, A. Hélary, P. Gutfreund, L. Léger, A. Chennevière, F. Restagno, submitted, 2023, https://arxiv.org/abs/2305.05960
- “Giant slip length at a supercooled liquid-solid interface“, S. Lafon, A. Chennevière, F. Restagno, S. Merabia, L. Joly, Phys. Rev. E, 2023, 107, 025101, https://doi-org/10.1103/PhysRevE.107.025101 (arxiv version: https://arxiv.org/abs/2207.12176)
- “Flow driven control of pulse width in excitable media“, A. Misselwitz, S. Lafon, J.-D. Julien, K. Alim, Phys. Rev. E., 2023, 107, 054218, https://link.aps.org/doi/10.1103/PhysRevE.107.054218 (arxiv version: https://arxiv.org/abs/2212.04920)
- “Reversible photocontrol of DNA coacervation“, S. Lafon, N. Martin, Methods in Enzymology, 2021, 646, 329-351, https://doi.org/10.1016/bs.mie.2020.06.013
- “The dual role of viscosity in capillary rise“, J. Delannoy, S. Lafon, Y. Koga, E. Reyssat, D. Quéré, Soft Matter, 2019, 15, 2757-2761, http://dx.doi.org/10.1039/C8SM02485E
Contact
- suzanne.lafon@universite-paris-saclay.fr
- +33 (0) 1 69 15 53 00
- Office O003, bat 510, campus Univ. d’Orsay, Orsay, 91400
PhD Student
Paris-Saclay University
Oct 2020 – Present Orsay, France. As a PhD, I joined both the group Soft matter at interfaces in Laboratoire de Physique des Solides in Orsay and the group Biophysics and Soft Matter in Laboratoire Léon Brillouin in the CEA Saclay.
Student
Ecole Normale Supérieure d’Ulm
Sep 2016– Aug 2020 Paris, France. I’ve been studying fundamental physics and chemistry for four years at the Ecole Normale Supérieure d’Ulm. During this time, I’ve done five interships in academia in Paris, Bordeaux and Göttingen.
Internships
- “Spontaneous emulsification and organisation at water/oil interface“, supervised by Teresa Lopez-Leon, Gulliver lab, ESPCI, Paris.
- “Kinetics of light-responsive liquid/liquid phase separation“, supervised by Nicolas Martin & Jean-Christophe Baret, CRPP, Pessac, France. Published: “Reversible photocontrol of DNA coacervation”, Lafon & Martin, Methodes in Enzymology 646 pp329-351 (2021).
- “Topological defects in a shell of cholesteric liquid crystals“, supervised by Teresa Lopez-Leon, Gulliver lab, ESPCI, Paris.
- “Effect of advection on pulse propagation in excitable media“, supervised by Jean-Daniel Julien & Karen Alim, MPIDS, Göttingen, Germany.
- “Early dynamics of capillary rise“, supervised by Joachim Delannoy, Etienne Reyssat & David Quéré, PMMH, ESPCI, Paris. Published: “The dual role of viscosity in capillary rise”, Delannoy, Lafon, Koga, Reyssat & Quéré, Soft Matter 13 (2019).