Ordering and Dynamics of Interacting Colloidal Particles under Soft Confinement

Colloids and Interfaces

卷:5

Ramón Castañeda-Priego¹  EdithC. Euán-Díaz²  Salvador Herrera-Velarde³ 

[1] Department of Physical Engineering, Division of Sciences and Engineering, Campus León, University of Guanajuato, Loma del Bosque 103, León 37150, Mexico;

[2] EBRAINS AISBL/IVZW, Troonstraat 98, 1050 Brussels, Belgium;

[3] Subdirección de Investigación y Posgrado, Tecnológico Nacional de México, Instituto Tecnológico Superior de Xalapa, Veracruz 91096, Mexico;

关键词: colloids;    confinement;    ordering;    locomotion;    Brownian dynamics;   

DOI  :  10.3390/colloids5020029

来源: DOAJ

【 摘 要 】

Confinement can induce substantial changes in the physical properties of macromolecules in suspension. Soft confinement is a particular class of restriction where the boundaries that constraint the particles in a region of the space are not well-defined. This scenario leads to a broader structural and dynamical behavior than observed in systems enclosed between rigid walls. In this contribution, we study the ordering and diffusive properties of a two-dimensional colloidal model system subjected to a one-dimensional parabolic trap. Increasing the trap strength makes it possible to go through weak to strong confinement, allowing a dimensional transition from two- to one-dimension. The non-monotonic response of the static and dynamical properties to the gradual dimensionality change affects the system phase behavior. We find that the particle dynamics are connected to the structural transitions induced by the parabolic trap. In particular, at low and intermediate confinement regimes, complex structural and dynamical scenarios arise, where the softness of the external potential induces melting and freezing, resulting in faster and slower particle diffusion, respectively. Besides, at strong confinements, colloids move basically along one direction, and the whole system behaves structurally and dynamically similar to a one-dimensional colloidal system.

【 授权许可】

Unknown