Monte Carlo simulations of copolymers at homopolymer interfaces: Interfacial structure as a function of the copolymer density

Abstract

By means of extensive Monte Carlo simulations of the bond fluctuation model, we study the effect of adding AB diblock copolymers on the properties of an interface between demixed homopolymer phases. The parameters are chosen such that the homopolymers are strongly segregated, and the whole range of copolymer concentrations in the two phase coexistence region is scanned. We compare the ``mushroom'' regime, in which copolymers are diluted and do not interact with each other, with the ``wet brush'' regime, where copolymers overlap and stretch, but are still swollen by the homopolymers. A ``dry brush'' regime is never entered for our choice of chain lengths. ``Intrinsic'' profiles are calculated using a block analysis method introduced by us in earlier work. We discuss density profiles, orientational profiles and contact number profiles. In general, the features of the profiles are similar at all copolymer concentrations, however, the profiles in the concentrated regime are much broader than in the dilute regime. The results compare well with self-consistent field calculations.

to appear in J. Chem. Phys

References in corpus (3)

• Intrinsic profiles and capillary waves at homopolymer interfaces: a Monte Carlo study
• Anomalous size-dependence of interfacial profiles between coexisting phases of polymer mixtures in thin film geometry: A Monte-Carlo simulation
• Diblock copolymers at a homopolymer-homopolymer-interface: a Monte Carlo simulation

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• Thermal Fluctuations in a Lamellar Phase of a Binary Amphiphile-Solvent Mixture: A Molecular Dynamics Study
• Localization of a multiblock copolymer at a selective interface: Scaling predictions and Monte Carlo verification
• A finite excluded volume bond-fluctuation model: Static properties of dense polymer melts revisited