Résumé
Large deformations of soft elastic beads spinning at high angular velocity in
a denser background fluid are investigated theoretically, numerically, and
experimentally using millimeter-size polyacrylamide hydrogel particles
introduced in a spinning drop tensiometer. We determine the equilibrium shapes
of the beads from the competition between the centrifugal force and the
restoring elastic and surface forces. Considering the beads as neo-Hookean up
to large deformations, we show that their elastic modulus and surface energy
constant can be simultaneously deduced from their equilibrium shape. Also, our
results provide further support to the scenario in which surface energy and
surface tension coincide for amorphous polymer gels.