Properties of polymer chains in confinement. Monte Carlo simulations

The main goal of this study was to investigate the dynamic properties of polymer chains located in a slit. The idealized models of polymers were built of united atoms (segments) restricted to vertices of a simple cubic lattice. The macromolecules were linear, cyclic and star-branched with f = 3 and f = 4 arms. The chains were at good solvent conditions and the only interaction between the segments was the excluded volume. The polymers were located in a slit formed by a pair of two parallel and impenetrable surfaces which were attractive for polymer segments. The properties of the model chains were determined by means of dynamic Monte Carlo method using a sampling algorithm based on chain’s local changes of conformation. It was shown, for all polymer architectures under consideration, that at a certain temperature and for a certain size of the slit the chains were adsorbed at one of the confining surfaces and after a certain period of time they detached from this surface and approached the opposite one. The conditions necessary for these jumps were determined. The influence of the internal chain architecture on the frequency of jumps was shown and discussed.