Heterogeneity of amorphous

The well-known heterogeneity of amorphous glassy pol5miers plastic deformation [1,2] allows to assume them nonhomogeneous systems. The same affirmation is valid in respect of semicrystalline pol5miers amorphous phase [3,4], As well nevertheless, both models of continues (let us remind, that Ihe known Dugdale model, often used for crazes characteristics, was developed originally for a metals [5]) and molecular concepts, are applied successfully for both classes polymers behavior description. In this cormection ihe question arises about scale, which can be considered as lower boimdary of models of continua applicability. 

These ideas might be used to explain the interesting results obtained recently by Williams et al.53 These workers observed formation of crystalline polystyrene when the reaction was initiated by triphenyl methyl potassium (or some other potassium metallo-organic compounds) in a hexane solution, but an amorphous polymer was formed in benzene. They point out that the catalyst is soluble in benzene but insoluble in hexane, and suggest that the heterogeneity of the catalyst is responsible for the results. Although this might be the case, an alternative explanation could be advanced.42 1... 

Materials mined from the Earth s crust are usually highly heterogeneous mixtures of amorphous and crystalline solid phases. Crushing and grinding operations are employed to liberate individual pure grains in the 10-50 pm size range. One of the most widely used (10 tons per... 

Heterogeneity of n values is related to a number of factors, including end groups, differences in density between amorphous and crystalline regions, anisotropic behavior of crystalline portions, incorporation of additives, and the presence of voids. 

Modified lignin materials may serve as components in (semi)conducting systems. All heterogeneous and amorphous polymeric complexes are now of interest for possible future employment in electrically conducting materials. 

A completely novel approach to technical electrolysis for anodic oxygen evolution from alkaline solution is the use of amorphous metals, i.e. chilled melts of nickel/cobalt mixtures whose crystallization is prevented by the addition of refractory metals like Ti, Zr, B, Mo, Hf, and P (46-51). For this type of material, enhanced catalytic activity in heterogeneous catalysis of gas-phase reactions has been observed (51). These amorphous metals are shown to be more corrosion resistant than the respective crystallized alloys, and the oxides being formed at their surfaces often exhibit a higher catalytic activity than those formed on ordered alloys, as shown by Kreysa (52-54). 

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