Behaviour of a Colloid close to an Air-Water Interface: Interactions and Dynamics

by Stefano Villa (Laboratorio Charles Coulomb, Montpellier (Francia))

Monday 27 May 2019, 14:00 → 15:30 Europe/Rome

Aula Conversi (Dip. di Fisica - Edificio G. Marconi)

Despite the relevance to environmental, biological and industrial processes, the motion of a colloidal particle close to a fluid interface and the way it interacts with the water surface are still largely elusive physical phenomena. We explored the system of individual colloidal particles close to an air-water interface by recording highly resolved 3D trajectories through a dual wave reflection interference setup. The results point out peculiar phenomena both in the particle-interface potential energy, which exhibits an unexpected equilibrium, and in the particle dynamics, as the air-water interface imposes different boundary conditions depending on the direction of the particle's motion.