Interaction between plates in a polymer melt

The effect of confining a polymer melt between two parallel plates has been investigated using Monte Carlo simulations. As soon as the distance between the plates becomes comparable to twice the radius of gyration of the polymer molecules in the bulk, the shape of all molecules is affected. Reducing the separation even more reduces the actual number of deformed molecules while the remaining molecules become on the average more deformed. The deformation of the molecules is due to those sections which are very near one of the two plates. The excess number of bonds parallel to the plates with respect to the bulk isotropic contribution is nearly independent of the distance between the plates. The correlation length is estimated to be of the order of the lattice spacing. All observations are in agreement with the predictions of de Gennes that no long-range force between plates in a melt should exist. © 1988 American Institute of Physics.