In solution crystallization, nucleation plays a decisive role in
determining the crystal structure and size distribution. Hence,
understanding the fundamentals of nucleation is crucial to achieve
control over these properties
Nucleation
process is known to be affected by many factors such as solvents
used for the preparation of supersaturated solution, impurities
presented in the solution, crystal seeds added in the system, and
cooling and agitation rate applied to the process
Among them, solvent effects are of particular practical
importance and can be exploited to control the process of crystallization,
and a wide variety of solvents can be employed when
dealing with organic compounds. While great efforts have been
made to investigate the solvent effects on crystal growth, few
papers are found addressing the influence of solvents on nucleation
For the solvent effect on crystal growth,
Bennema (1992) suggested that a favorable interaction with
solvent could reduce surface tension and transform a smooth
interface to a rough one, thus promoting the rate of crystal growth.
On the other hand
indicated that
desorption of a preferentially adsorbed solvent molecule may
cause additional energy barrier, and the growth rate could consequently
be reduced. Solvents will also have influence on the
aggregation state