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Chapter II Solution Growth….
2.20.1 Visual observation method
Figure :2.14 Constant temperature bath. Figure :2.15 Specially designed
container for induction period measurement.
In the present study, the experimental technique used to
measure induction period is the modification of technique used by Mullin [97]
and Joshi and Antony [98]. The solution supersaturated at 35 ºC of both pure
and amino acids doped KDP were prepared in accordance with available data
of solubility of KDP. To ensure that any unwanted metallic or non-metallic
impurity do not affect the nucleation process, recrystallized samples of Analar
Grade KDP powder and double distilled water were used. To minimize the
evaporation from the surface,the saturated solution was kept in the specially
designed glass vessel, which is shown in figure (2.15). Small drop of oil was
also kept on the solution. The volume of solution taken for each experiment
was 100 ml and it was preheated up to 40 ºC with stirring to achieve
homogeneous concentration and temperature through out the volume of
solution. To measure the temperature of solution exactly similar dummy
vessel was used in which solution of same volume was kept. Normally, the
time required for the growth of critical nucleus to a detectable size is negligibly
small compare to time needed between the achievements of super-saturation
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