and depend on the proportions of nucleation and crystal growth rates. If Crystal size particle size distribution nucleation rate (Vg) is lower than crystal growth rate (Vkn) (Vg< there are few nuclei formed and the Vkn), process shifts toward growing large crystals. If, however, nucleation rate is higher than crystal growth rate (Vg> the result is a mass of small crystals. Vkn), Nucleation is if nucleation is spontaneous due to supersaturation in the solution. homogenous, Heterogenous occurs when it is triggered by suspended foreign matter (e.g. mechanical contamination, seeding nucleation crystals) or external impulse (e.g. agitation or shaking). The two mechanisms are fundamentally different. The driving force behind homogenous nucleation is supersaturation. is: Nucleation rate (4.) number of nuclei, n time, t current concentration of solution, c concentration of supersaturated solution, cm nucleation rate constant, kg empirical parameter. i is: Diffusion nucleation rate (5.) crystal mass, m time, t nucleation rate constant, kgn nucleus surface, A concentration of solution, c concentration on the nucleus surface. cf is: Convection nucleation rate (6.) constant typical of circulation, k surface reaction rate constant. κ The parameters of the end product of crystallization depend on the solvents used in recrystallization. Frequently used solvents, which are suited for being used for crystallization by themselves or as components of a compound: water,
Crystal size and particle size distribution depend on the proportions of nucleation and crystal growth rates. If nucleation rate (Vg) is lower than crystal growth rate (Vkn) (Vg< Vkn), there are few nuclei formed and the process shifts toward growing large crystals. If, however, nucleation rate is higher than crystal growth rate (Vg> Vkn), the result is a mass of small crystals. Nucleation is homogenous, if nucleation is spontaneous due to supersaturation in the solution. Heterogenous nucleation occurs when it is triggered by suspended foreign matter (e.g. mechanical contamination, seeding crystals) or external impulse (e.g. agitation or shaking). The two mechanisms are fundamentally different. The driving force behind homogenous nucleation is supersaturation. Nucleation rate is: (4.) n number of nuclei, t time, c current concentration of solution, cm concentration of supersaturated solution, kg nucleation rate constant, i empirical parameter. Diffusion nucleation rate is: (5.) m crystal mass, t time, kgn nucleation rate constant, A nucleus surface, c concentration of solution, cf concentration on the nucleus surface. Convection nucleation rate is: (6.) k constant typical of circulation, κ surface reaction rate constant. The parameters of the end product of crystallization depend on the solvents used in recrystallization. Frequently used solvents, which are suited for being used for crystallization by themselves or as components of a compound: water,