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

A. Werner; F. Schmid; M. Mueller

doi:10.1063/1.478432

Home/Archive/arXiv

arXiv · cond-mat/9812104

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

A. Werner·F. Schmid·M. Mueller

View original source ↗Read source document ↗Export metadata ↓

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.

Explore related subjects

cond-mat.soft cond-mat.mtrl-sci

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

A. Werner, F. Schmid, M. Mueller. 1998-12-07. Monte Carlo simulations of copolymers at homopolymer interfaces: Interfacial structure as a function of the copolymer density. https://doi.org/10.1063/1.478432

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Solvent-induced memory effects in a model electrolyte

The fluctuations of ions in polar solvents remain poorly understood theoretically due to the complex coupling between ionic motion and solvent polarization. Indeed, while all-atom resolution can be achieved in numerical simulations, analytical approaches require suitable levels of coarse-graining. In this work, we describe ions and solvent molecules as interacting Brownian particles and use stochastic density functional theory to derive a generalized Langevin equation for the ionic charge density, explicitly accounting for solvent-mediated memory effects. In the regime where there is a clear timescale separation between fast solvent and slow ion dynamics, we obtain simple expressions for dynamical charge structure factors, which are validated by BD simulations. For slow solvents, we predict an emerging two-step relaxation in ionic dynamics. These results provide a mesoscopic approach for ion-solvent dynamics and open pathways to study fluctuation-induced phenomena in electrolytes.

cond-mat.soft↗

arXiv2026

Liquid crystalline order and its impact on shape evolution of fluid lipid membranes

We consider extensions of the classical curvature-elasticity free energy for a fluid lipid membrane, explicitly treating the liquid crystal structure of the membrane, which results from the lipid molecules that are, on average, oriented normal to the surface. Locally varying liquid crystal order leads to local variations in bending rigidities and surface viscosity and thus influences the shape evolution. This provides a multiscale coupling between the local membrane mechanics on the level of the lipids and the mesoscopic length and time scales of biological functions. Numerical simulations in the one-constant approximation demonstrate the impact of local membrane mechanics on the emerging equilibrium shapes. These shapes not only depend on the specified conserved surface area and enclosed volume, as for the classical curvature-elasticity free energy, but also the elastic parameter and are characterized by a reduced liquid crystal order at highly curved regions. The modified shapes and their varying liquid crystal order, as function of curvature, provide experimentally testable properties. Exploring the dynamic evolution demonstrate a tight coupling of tangential flow, shape evolution and liquid crystalline order. We further point to model extensions towards lipid phase separation and asymmetric lipid bilayers and biological implications.

cond-mat.soft↗

arXiv2026

From Action Principle to Stochastic Thermodynamics of Elastic and Viscous Active Matter

Motivated by the complex material properties of living matter, we derive a framework of stochastic thermo- and elastodynamics for active materials from the classical principle of least action and the Rayleighian formalism for external forces. Our approach couples the local barycentric collective coordinate and the streaming velocity as the canonical conjugate pair, which unifies various descriptions of elastic and viscous soft matter, including Helfrich theory for lipid membranes, linear and nonlinear elasticity of thin shells and deformable droplets, as well as hydrodynamics of active and passive fluids. The Lagrangian mechanics of collective field variables permits direct applications of the results and theorems from statistical mechanics to existing models of complex soft and living matter. To illustrate the potential applications of stochastic elastodynamics in biology, we derive and simulate a boundary-driven deformation model of an elastic cell nucleus in the presence of fluctuations.

cond-mat.soft↗