by
Dominic Tildesley(Director CECAM, Lausanne Switzerland)
→
Europe/Rome
Aula Majorana (Dipartimento di Fisica)
Aula Majorana
Dipartimento di Fisica
Description
The lubrication of surfaces coated with polymers is an important technological problem and one that is difficult to solve effectively using non-equilibrium molecular dynamics with atomistic models. In this talk we describe the development of dissipative particle dynamics as an important technique for modelling polymers and surfactants in ionic solvents.
In particular the compression-dependence of the friction coefficients of neutral and charged polymer brushes at the same surface coverage is studied using dissipative particle dynamics at two different shear rates.
We conclude that the kinetic friction coefficient between charged brushes is higher than that of neutral brushes at low compressions and smaller at high compressions.
Moreover, the unexpected behavior of the shear deformation-induced structural heterogeneities in charged polymer brushes calls for further experiments to elucidate this local reorganization of the ions in adsorbed charged polymers.
