Conformational properties and entropic partitioning of topologically complex polymers under confinement

The effect of molecular topology on the properties of isolated polymer chains trapped in a repulsive slit was investigated using off-lattice Monte Carlo simulations. Three different chain architectures were studied: star-branched, dendritic, and hyperbranched chains. The linear dimensions of the polymer coil, the density profiles across the slit, and the confinement force F were obtained from the simulations and compared with those of linear chains. It is found that scaling theory for linear chains describes well all the properties examined of star molecules and the scaling of the linear dimensions of dendrimers and hyperbranched polymers. The relative partition coefficient at the dilution limit was estimated from the data of F vs slit separation D. It is shown that for very narrow D branched polymers tend to be depleted in the pore relative to linear chains with the same molecular weight; this trend is reversed, however, at large D.