During my PhD, I am interested in the dynamics of liquids near solid surfaces. I use molecular dynamics to probe the friction Lennard-Jones fluids on a model wall as the liquid becomes supercooled. I also study the slip and friction of polymer solutions on ideal substrate combining rheology, photobleaching techniques and neutron reflectivity. In particular, I am focusing on the dynamics of polymer chains near the wall as the chains are cooled down near their glass transition temperature.
- Polymer physics
- Molecular Dynamics
- Neutron reflectivity
- 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
Using a novel approach, we quantify the friction between a viscous polymer solution and a smooth surface. In particular, we look at the shear-rate and temperature dependences of the friction coefficient.
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.
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.
See https://doi-org/10.1103/PhysRevE.107.025101 for more information.
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.
See https://arxiv.org/abs/2305.05960 for more information.
Adsorption kinetics of PDMS melts
We study the temperature effect on the adsorption kinetics of polymer melts on silicon wafers. We show that PDMS melts adsorb in a peculiar way compared to other polymer melts, and this is likely to be due to its strong interaction with the silicon surface.
- “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)
- “Confinement effect on poly(ionic liquid) interfacial structure“, T. Outerelo-Corvo, S. Lafon, A. Hemmerle, E. Drockenmuller, F. Restagno, A. Chennevière, in preparation, 2023
- “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)
- “Interaction between proteins and cellulose in a liquid crystalline media: Design of a droplet based experimental platform“, H. Voisin, E. Bonnin, M. Marquis, C. Alvarado, S. Lafon, T. Lopez-Leon, F. Jamme, I. Capron, International Journal of Biological Macromolecules, 2023, 245, 125488, https://doi.org/10.1016/j.ijbiomac.2023.125488
- “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
- +33 (0) 1 69 15 53 00
- Office O106, bat 510, campus Univ. d’Orsay, Orsay, 91400
You can find a curriculum below.CV-Suzanne-Lafon
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.
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.
- “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).