Conformational properties and entropic partitioning of topologically complex polymers under confinement

The effect of molecular topology on the properties of isolated polymer chai ns trapped in a repulsive slit was investigated using off-lattice Monte Car lo simulations. Three different chain architectures were studied: star-bran ched, dendritic, and hyperbranched chains. The linear dimensions of the pol ymer coil, the density profiles across the slit, and the confinement force F were obtained from the simulations and compared with those of linear chai ns. It is found that scaling theory for linear chains describes well all th e properties examined of star molecules and the scaling of the linear dimen sions of dendrimers and hyperbranched polymers. The relative partition coef ficient at the dilution limit was estimated from the data of F vs slit sepa ration D. It is shown that for very narrow D branched polymers tend to be d epleted in the pore relative to linear chains with the same molecular weigh t; this trend is reversed, however, at large D.