Localization of a multiblock copolymer at a selective interface: Scaling predictions and Monte Carlo verification

Abstract

We investigate the localization of a hydrophobic - polar (HP) - regular copolymer at a selective solvent-solvent interface with emphasis on the impact of block length $M$ on the copolymer behavior. The considerations are based on simple scaling arguments and use the mapping of the problem onto a homopolymer adsorption problem. The resulting scaling relations treat the gyration radius of the copolymer chain perpendicular and parallel to the interface in terms of chain length N and block size M, as well as the selectivity parameter \chi . The scaling relations differ for the case of weak and strong localization. In the strong localization limit a scaling relation for the lateral diffusion coefficient D is also derived. We implement a dynamic off-lattice Monte - Carlo model to verify these scaling predictions. For chain lengths in a wide range (32 < N < 512) we find good agreement with the scaling predictions.