Dynamics of confined colloid-polymer mixtures
نویسندگان
چکیده
We investigate the effect of confinement on particle dynamics in mixtures of colloidal particles and non-adsorbing depletant polymers that serve as models for attractive suspensions. Holding the volume fraction of particles and the polymer concentration constant, the dynamics of the particles become increasingly slow as the suspensions are confined in thin wedgeshaped cells. Confocal micrographs of the confined samples suggest that clustering and solidification contribute to changes in the dynamics of mixtures in which particles interact via a strong attraction. The dynamics of non-aggregating particles that do not undergo a phase transition also become slower in confinement, suggesting that additional mechanisms must contribute to slow dynamics in confined colloid-polymer mixtures.
منابع مشابه
Confocal imaging of confined quiescent and flowing colloid-polymer mixtures.
The behavior of confined colloidal suspensions with attractive interparticle interactions is critical to the rational design of materials for directed assembly(1-3), drug delivery(4), improved hydrocarbon recovery(5-7), and flowable electrodes for energy storage(8). Suspensions containing fluorescent colloids and non-adsorbing polymers are appealing model systems, as the ratio of the polymer ra...
متن کاملHydrodynamic mechanisms of spinodal decomposition in confined colloid-polymer mixtures: a multiparticle collision dynamics study.
A multiscale model for a colloid-polymer mixture is developed. The colloids are described as point particles interacting with each other and with the polymers with strongly repulsive potentials, while polymers interact with each other with a softer potential. The fluid in the suspension is taken into account by the multiparticle collision dynamics method (MPC). Considering a slit geometry where...
متن کاملAdsorption properties of a colloid-polymer mixture confined in a slit pore.
The soft fundamental-measure theory, which was based on the additive colloid-polymer mixture [M. Schmidt, Phys. Rev. E 62, 3799 (2000)] has been employed to investigate the adsorption of a colloid-polymer mixture within a hard slit pore. The calculated results show that the adsorption for the confined colloid-polymer mixture is very different from those of the colloid-colloid and polymer-polyme...
متن کاملEffect of excluded volume interactions on the interfacial properties of colloid-polymer mixtures.
We report a numerical study of equilibrium phase diagrams and interfacial properties of bulk and confined colloid-polymer mixtures using grand canonical Monte Carlo simulations. Colloidal particles are treated as hard spheres, while the polymer chains are described as soft repulsive spheres. The polymer-polymer, colloid-polymer, and wall-polymer interactions are described by density-dependent p...
متن کاملConfinement-induced solidification of colloid-polymer depletion mixtures.
Using a model colloid-polymer suspension, we show that confinement induces solidification in attractive colloidal suspensions via a fundamentally different route from that active in hard sphere colloidal suspensions. For a range of polymer concentrations, the suspensions undergo a phase transition from a colloidal fluid of clusters to a colloidal gel as confinement increases while polymer and p...
متن کامل