Eur. Phys. J. E (2013) 36: 90
https://doi.org/10.1140/epje/i2013-13090-3

Regular Article

Colloidal particles in a drying suspension: A phase field crystal approach

¹ Department of Physics, Nabadwip Vidyasagar College, Nabadwip, 741302, Nadia, India
² Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187, Dresden, Germany
³ TIFR Centre for Interdisciplinary Sciences, 21 Brundavan Colony, 500075, Narsingi, Hyderabad, India
⁴ Centre for Advanced Materials, Indian Association for the Cultivation of Science, 700032, Jadavpur, Kolkata, India

^* e-mail: nirmalendu.phy@gmail.com
^** e-mail: arnab@pks.mpg.de
^*** e-mail: surajit@tifrh.res.in

Received: 7 November 2012
Revised: 3 May 2013
Accepted: 1 July 2013
Published online: 15 August 2013

Abstract

Using a phase field crystal model we study the structure and dynamics of a drop of colloidal suspension during evaporation of the solvent. We model an experimental system where contact line pinning of the drop on the substrate is non-existent. Under such carefully controlled conditions, evaporation of the drop produces an ordered or disordered arrangement of the colloidal residue depending only on the initial average density of solute and the drying rate. We obtain a non-equilibrium phase boundary showing amorphous and crystalline phases of single component and binary mixtures of colloidal particles in the density-drying rate plane. While single-component colloids order in the two-dimensional triangular lattice, a symmetric binary mixture of mutually repulsive particles can be ordered into three triangular sub-lattices in two dimensions. Two of them are occupied by the two species of particles with the third sub-lattice vacant.