Fred BROUWER, éminent spécialiste en photophysique et photochimie et professeur au Van’t Hoff Institute for Molecular Sciences de l’université d’Amsterdam, donnera une conférence « What can fluorescence microscopy tell us about friction? » le Lundi 12 Décembre 2022 à 11h en Salle Marie Curie du CEISAM.
Friction is a phenomenon of great importance in daily life, in transportation and
other man-made technologies, but also in biology and geology. On the microscopic scale
friction arises at the points of contact between two objects. In our research we use
fluorescent rotor molecules in combination with microscopy to study such contacts. We
can show where precisely two objects are in contact, and how the contact changes when
a force is applied that initiates a sliding motion. With a fluorescent neat liquid, we can see
how a thin layer of liquid lubricates the contact. Finally, fluorogenic mechanochromic
dyes are used to measure the shear force between two surfaces, and we can see how
different regions of a contact reach the limit where sliding can start at different times. In
all cases, we will discuss the (photo)chemical properties of the molecules that allow us to
learn about friction.