Crystal morphology control stable

The induction times of carbamazepine polymorphs [monoclinic, CBZ(M) and trigonal, CBZ(Trg)] were evaluated by optical microscopy. The polymorphs were identified by their crystal morphology where CBZ(M) crystallizes as prismatic crystals and CBZ(Trg) crystallizes as needles, which were confirmed by X-ray powder diffraction. It was determined that under constant supersaturation concomitant crystallization is favored in solvents that accept and donate hydrogen bonds (ethanol, methanol, isopropanol, etc.). However, the metastable CBZ(Trg) polymorph preferentially crystallized in solvents that primarily accept hydrogen bonds (ethyl acetate, methyl acetate, 2-butanone, etc.) with the stable CBZ(M) polymorph crystallizing at least an hour later. The induction times of CBZ polymorphs did not decrease with increases in solubility, suggesting that nucleation is not controlled by solubility differences. It was determined that CBZ polymorph nucleation was governed by the specific solute-solvent interactions that occurred in solution to... 

The growth of semicrystalline NIF in preference to that of the highly crystalline F2 form is a typical example of crystallization kinetics controlling polymer morphology. The best known example is, of course, the very fact that thin folded-chain crystals form in preference to the more stable extended-chain crystals. 

During paste preparation, exothermic reactions proceed which cause the temperature in the paste mixer to rise. In order to obtain reproducibly a paste with definite phase composition and crystal morphology, which would ensure high and stable battery performance, the temperature in the mixer should be monitored and controlled continuously throughout the process of paste preparation. 

The microwave technique is also regarded beneficial in the synthesis of mesoporous silicates with a promotion of homogeneous nucleation, faster crystallization, formation of uniform crystals and small crystallites, facile morphology control, avoidance of undesirable phases by shortening the synthesis time, and so on (150). In aluminophosphate system, thermally stable Fe- and... 

Polymorphs and solvated crystals is generally observed in pharmacentical indnstry [1], The bioavailability, stability, solnbility, and morphology of the pharmacentical products are very influenced by polymorphs [2-7], therefore the control of the polymorphic crystallization is very important. The crystallization process of polymorphs and solvated crystals is composed of competitive nucleation, growth, and transformation from a meta-stable form to a stable form [4], Furthermore, the crystallization behavior is influenced by various controlling factors such as temperature, supersaturation, additives and solvents [8], In order to perform the selective crystallization of the polymorphs, the mechanism of each elementary step in the crystallization process and the key controlling factor needs to be elucidated [8], On the other hand, we reported for L-Glutamic acid and L-Histidine system previously [4] that the nucleation and transformation behaviors of polymorphs depend on the molecular stractures. If the relationship between molecular stmcture and polymorphic crystallization behavior is known, the prediction of the polymorphism may become to be possible for the related compound. However, detail in such relationship is not clearly understood. 

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