Admixtures on Nucleation

Several mechanisms of nucleation can be distinguished according to conditions in a supersaturated solution [178] nucleation - primary - homogeneous 

A basic criterion for this distinction I178J is the presence or absence of a solid phase. While primary nucleation occurs In the absence of solid particles of the crystallized substance, secondary nucleation Is dependent on the presence of crystals. For homogeneous nucleation, no solid phase Is required, while heterogeneous nucleation Is catalytlcally Initiated by any foreign surface. Many details on the mechanisms of secondary nucleation can be found In the literature [152,177,178,214,215,225]. 

Strong effects of the admixtures can be observed with primary nucleation and with secondary nucleation due to mechanisms of the Interphase. There are several papers dealing with the theory of the effect of admixtures on nucleation In addition to those mentioned below, l.e. papers (23,78,157). 

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