Seminar: PhD Laura LE BRAS

Laura LE BRAS
NISM, UNamur, Belgium

Abstrat (PDF)
Light is at the origin of many natural processes and can be converted into electricity, heat or
mechanical energy. If the mechanisms of the conversion of light into electricity (Photovoltaics) and
heat (Solar oven) are now well understood, the last one, the conversion into a mechanical energy,
is still unclear and most often comes from a cascade of complex mechanisms. Being able to
control the matter and its movement with light thus represents a great challenge. Phototropism,
actinotropism, photonastism and nyctinastism are as many examples of what light can induce
when it meets matters in nature. As the mechanisms behind this light/mechanical energy
conversion are complicated, one needs to pave the way with pioneering studies to enable the
comprehension of those phenomena at different time and spatial scales. In this sense,
computational chemistry and molecular modeling are valuable tools.
We propose here to consider a light-responsive polymer containing embedded photochromic
molecules and to develop a tailored computational protocol able to tackle different aspects (explicit
description of the environment, photochemistry in a polymer matrix, environmental constraints and
deformation, optical properties, etc) of this complex system and phenomenon. By combining
quantum mechanical calculations and molecular dynamics simulations we will build a realistic
polymeric environment for the photochromic molecules and unravel their mutual influence and
interaction. Finally, we will lay the foundation stone for the consideration of optomechanical
phenomena from a theoretical point of view1.
1 L. Le Bras, C. Lemarchand, S. Aloïse, C. Adamo, N. Pineau, and A. Perrier J. Chem. Theory
Comput. 2020 16 (11), 7017-7032