Hybrid Time-Dependent Ginzburg–Landau Simulations of Block Copolymer Nanocomposites: Nanoparticle Anisotropy

Activity-Driven Emulsification of Phase-Separating Binary Mixtures

Active particles self-assemble into emergent structures that respond sensitively to external constraints. Consequently, their behavior under confinement is complex, especially in soft confined media, leading to diverse emergent morphologies. Through computer simulations, we investigate the dynamical interplay between active Brownian particles and a binary mixture. Our results show that active particles stabilize nonequilibrium morphologies, arresting coarsening by exerting active pressure that competes with surface tension. For moderate activities, particles stabilize an active emulsion with a well-defined droplet size. At higher activities, when particles can cross the liquid domains, a dynamic emulsion with large droplet dispersion is sustained. Furthermore, active particles drive phase-separated mixtures away from equilibrium configurations, demonstrating a rich coassembly behavior due to competing energy scales in the system.

Emergent structures in active block copolymer composites

Block copolymer melts offer unique templates to control the position and alignment of nanoparticles due to their ability to self-assemble into periodic ordered structures. Active particles are shown to coassemble with block copolymers leading to emergent organized structures. The block copolymer acts as a soft template that can control the self-propulsion of active particles, both for interface-segregated and selective nanoparticles. At moderate activities, active particles can form organized structures such as polarized trains or rotating vortices. At high activity, the contrast in the polymeric and colloidal timescales can lead to particle swarms with distorted block copolymer morphology, due to the competition between polymeric self-assembly and active Brownian self-propulsion.

Implicit-Solvent Coarse-Grained Simulations of Linear-Dendritic Block Copolymer Micelles

The design of nanoassemblies can be conveniently achieved by tuning the strength of the hydrophobic interactions of block copolymers in selective solvents. These block copolymer micelles form supramolecular aggregates, which have attracted great attention in the area of drug delivery and imaging in biomedicine due to their easy-to-tune properties and straightforward large-scale production. In the present work, we have investigated the micellization process of linear-dendritic block copolymers in order to elucidate the effect of branching on the micellar properties. We focus on block copolymers formed by linear hydrophobic blocks attached to either dendritic neutral or charged hydrophilic blocks. We have implemented a simple protocol for determining the equilibrium micellar size, which permits the study of linear-dendritic block copolymers in a wide range of block morphologies in an efficient and parallelizable manner. We have explored the impact of different topological and charge properties of the hydrophilic blocks on the equilibrium micellar properties and compared them to predictions from self-consistent field theory and scaling theory. We have found that, at higher degrees of branching in the corona and for short polymer chains, excluded volume interactions strongly influence the micellar aggregation as well as their effective charge.