title: Encapsulation of spherical nanoparticles by colloidal dimers.
abstract: We study by Monte Carlo simulation the coating process of colloidal dimers onto spherical nanoparticles. To this end we investigate a simplified mixture of hard spheres (the guest particles) and hard dimers formed by two tangent spheres of different sizes (the encapsulating agents) in an implicit-solvent representation; in our scheme, the range of effective interactions between the smaller particle in a dimer and a guest sphere depends on their relative size. By tuning the size and concentration of guests, under overall dilute conditions a rich phase behavior emerges: for small sizes and/or low concentrations, the preferred arrangement is compact aggregates (capsules) of variable sizes, where one or few guest particles are coated with dimers; for larger sizes and moderate guest concentrations, other scenarios are realized, including equilibrium separation between a guest-rich and a guest-poor phase. Our results serve as a framework for a more systematic investigation of self-assembled structures of functionalized dimers capable of encapsulating target particles, like for instance bioactive substances in a colloidal dispersion.
authors.affiliation: Dipartimento di Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra, Universitá degli Studi di Messina, Viale F. Stagno d'Alcontres 31, 98166 Messina, Italy. gmunao@unime.it.
authors.forename: Gianmarco
authors.initials: G
authors.lastname: Munaò
authors.forename: Dino
authors.initials: D
authors.lastname: Costa
authors.forename: Santi
authors.initials: S
authors.lastname: Prestipino
authors.forename: Carlo
authors.initials: C
authors.lastname: Caccamo