EFFECT OF SHEER ON THE DESORPTION OF OLIGOMERS IN NANOSCOPICALLY CONFINED FILMS

Bitsanis et al. J. Chem. Phys. 99, 5520 (1993) found that in nanoscopi cally confined films between strongly physisorbing surfaces chains wit h many contacts with the walls are irreversibly adsorbed. When shear i s imposed to these systems molecular dynamics (MD) simulations show th at the majority of the adsorbed oligomers adopts flat conformations on top of the walls. Although these conformations are characterized by h igh molecular adsorption energies, the same MD simulations show that d esorption is strongly promoted by shear. The underlying mechanism is d iscussed.