Solution Plots Growth
In the plot process variables, the graphs show the temperature and total solvent and antisolvent mass profile, respectively.
The temperature graph can be separated into three regions:
Region I: strong linear decrease of temperature
Region II: constant temperature
Region III: lower linear decrease of temperature
The total mass stays constant throughout the process.
The concentration decreases permanently because mass of the solute is taken away due to the growth rate.
The supersaturation plot is a representation of the following equation:
where all of the time the decrease in the denominator prevails over the decrease in the nominator.
In this plot the concentration is shown dependent on the temperature. Basically, the information from the concentration and supersaturation plot are respresented in one plot. The three regions mentioned above can be recognized again.
Since in this case the growth rate is size dependent, bigger crystals grow faster than smaller ones. As a consequence, smaller particles at the outer part of the distribution curve are pushed further outside. This leads to a widening of the distribution plot. The following graph shows the inital distribution in blue and the final one in green.
In this plot, the 0-th and 3-rd moment of the distribution and the volume average length are plotted. The moments are defined as
and the volume average length is defined as
