The role of cracks in the crystal nucleation process of amorphous griseofulvin
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In this paper we have investigated the recrystallization properties of amorphous griseofulvin obtained by melt quenching. We have shown that the maximum nucleation rates of crystalline forms 2 and 3 are located around the glass transition temperature. However, it appears that these nucleation rates are strongly increased by the sudden formation of cracks into the amorphous solid during deep quenches below Tg. Suitable thermal treatments have revealed that these cracks strongly promote the development of crystalline nuclei, but do not produce the nuclei themselves. The investigations have been performed by differential scanning calorimetry and by thermal microscopy.
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