Temperature effects on the transition from nucleation and growth to Ostwald ripening

Madras, Giridhar and McCoy, Benjamin J (2004) Temperature effects on the transition from nucleation and growth to Ostwald ripening. In: Chemical Engineering Science, 59 (13). pp. 2753-2765.

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Abstract

Condensation, involving nucleation, growth, and ripening from a metastable state,is an important but complex phase transition process. The effect of physical parameters, including temperature, on condensation dynamics, the competition between homogeneous and heterogeneous (seeding) nucleation, and the separation of polymorphs are among several issues of practical interest. We present a model based on population dynamics that describes the time evolution of the particle size distributions for condensation of the 6uid phase and consequent decline in supersaturation. The crucial effect of interfacial curvature on energy, and hence on particle size (Gibbs–Thomson Effect), causes larger particles to be less soluble, so that smaller particles dissolve and eventually vanish (denucleate). Numerical solutions of the governing equations show the transition from nucleation and growth to ripening occurs over a relatively long time period. The in6uence of temperature on these phenomena is primarily through its effect on interfacial energy, growth rate coe9cients, and equilibrium solubility. Temperature programming is proposed as a potential method to control the size distribution during the phase transition. The model suggests conditions to suppress homogeneous nucleation by seeding. We also explore how a temperature program for cooling crystallization based on different properties of the crystal forms can separate two crystal polymorphs.

Item Type:	Journal Article
Publication:	Chemical Engineering Science
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Crystal size distributions;Crystal growth;Denucleation; Distribution kinetics;Nucleation;Ostwald ripening
Department/Centre:	Division of Mechanical Sciences > Chemical Engineering
Date Deposited:	27 Apr 2006
Last Modified:	18 Jan 2012 09:40
URI:	http://eprints.iisc.ac.in/id/eprint/6494

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