Abstract
Ian Williams: „The Colloidal Corral: An Experimental Model of Hard Discs Under Soft Confinement”
University of Bristol, United Kingdom
Ian Williams, Paul Bartlett and C. Patrick Royall
Confinement is known to drastically modify the structure, dynamics and phase behaviour of a liquid when compared to the bulk[1,2]. Densely packed systems under spatial confinement tend to adopt structures mimicking the symmetry of their confinement. Using a combination of gravitational and optical fields we create a strongly confined, two-dimensional model system. Holographic optical tweezers define a ring of colloidal microspheres and the interior of this region is populated with similar particles. The result is a two-dimensional system with controllable density confined by a soft, circular boundary. The structural and dynamical behaviour of such a system is modified with respect to bulk behaviour at comparable densities and even with respect to similar systems confined with a hard boundary. Furthermore, the softness of the wall facilitates direct measurements of pressure in these systems. [1]
Reference:
- K. Watanabe, T. Kawasaki and H. Tanaka. Nature Materials, Vol. 10, No. 7. pp. 512-520. 2011.
- Z. T. Németh und H. Löwen. J. Phys.: Cond. Matt., 10(28):6189–6204, 1998.