I am doing some work on miscibility and re-crystallization of amorphous drugs. I want to know about the effect of cooling rate on crystalline kinetics.
You can try to make DSC curves on samples cooled down under different rates. From the crystallization curves and the re-heating curves (recrystallization and melting) you may decide the otimum cooling rate.
You can try to make DSC curves on samples cooled down under different rates. From the crystallization curves and the re-heating curves (recrystallization and melting) you may decide the otimum cooling rate.
While the polymer is still in the melt, as soon as it exits the machine you've gotta quench it in cold something immediately. Depending on the polymer you can use ice water, dry ice cooled IPA, or even liquid nitrogen. Quenching from the melt is the only way you can get an amorphous polymer.
Ad Ravi: yes, definitely. Two factors affect crsytallization: nucleation rate and growth rate. If the nucleation is fast and growth is faster, you will get sevaral small cystals. If the reverse is true, you will get fewer large crystals. If the nucleation is hindered by viscosity effect and the growth is also slow, you may get amorphours material (in non-equlirium state). The faster the cooling the higher the probability of obtaining amorphous material.
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials Chemistry