Molecular dynamics simulations of PMMA slabs: role of annealing conditions
Date of this Version9-2013
We use molecular dynamics simulations with the DREIDING force field to predict the molecular structure of thin PMMA slabs and characterize their properties. The slabs are created by uniaxial deformation of bulk samples at a high temperature followed by a relaxation and annealing to room temperature. Our simulations predict a free surface energy of similar to 0.1 J m(-2) in good agreement with experimental measurements and a density away from the free surfaces similar to that of the bulk. We find that mechanical constraints during annealing affect the molecular structure of the slabs and their free surface energy; slabs composed of molecular chains elongated along the surface normal exhibit lower surface energies than those with isotropic chain structures.
Nanoscience and Nanotechnology