Glass-forming liquids transport properties

C. Similarity of GB Mobility to Transport Properties of Glass-Forming Liquids... 

In contrast, for glass-forming liquids in the high viscosity region, transport in the liquid is difficult and the kinetic factor is quite small. The effect of this lower mobility on the nucleation frequency will be considered later in the present section. It should first be noted, however, that for many glassforming systems the assumption of a similarity between the transport process at the nucleus-matrix interface and transport in bulk liquid does not sufficiently specify the kinetic factor. The difficulty is related to the lack of reliable measurements of liquid diffusivity and the absence of a satisfactory model for relating this diffusivity to other properties of the materials. 

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