2006/02/15 by R. L. C. Vink, Kurt Binder, K. Binder +2
Chemistry · Engineering · Materials Science · Mathematics · Physics and Astronomy · #Binodal #Chemistry #Colloid #Condensed matter physics #Critical exponent #Critical phenomena #Critical point (mathematics) #Crossover #Exponent #Geometry #Ising model #Material Dynamics and Properties #Mathematical physics #Mathematics #Monte Carlo method #Phase (matter) #Phase Equilibria and Thermodynamics #Phase diagram #Phase transition #Physics #Quantum mechanics #Renormalization group #Scaling #Statistical physics #Statistics #Theoretical and Computational Physics #Universality (dynamical systems) #cond-mat.soft
paper · pdf · doi:10.1103/physreve.73.056118
published as Phys. Rev. E 73, 056118 (2006) · 12 pages, 10 figures
arxiv created 2006/02/15 · openalex publication_date 2006/05/19 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate the influence of confinement on phase separation in colloid-polymer mixtures. To describe the particle interactions, the colloid-polymer model of Asakura and Oosawa [J. Chem. Phys. 22, 1255 (1954)] is used. Grand canonical Monte Carlo simulations are then applied to this model confined between two parallel hard walls, separated by a distance D = 5 colloid diameters. We focus on the critical regime of the phase separation and look for signs of crossover from three-dimensional (3D) Ising to two-dimensional (2D) Ising universality. To extract the critical behavior, finite size scaling techniques are used, including the recently proposed algorithm of Kim et al [Phys. Rev. Lett. 91, 065701 (2003)]. Our results point to "effective" critical exponents that differ profoundly from 3D Ising values, and that are already very close to 2D Ising values. In particular, we observe that the critical exponent of the order parameter in the confined system is smaller than in 3D bulk, yielding a "flatter" binodal. Our results also show an increase in the critical colloid packing fraction in the confined system with respect to the bulk. The latter seems consistent with theoretical expectations, although subtleties due to singularities in the critical behavior of the coexistence diameter cannot be ruled out.