Kraus model aggregates

Kraus model of deagglomeration-reagglomeration of filler aggregates, assimilated to "soft spheres."... 

To consider that deagglomeration and agglomeration are two symmetrical processes is surely a strong hypothesis and likely the reason for the deficiencies of the Kraus model. In order to somewhat circumvent it, recent theoretical developments were made with an explicit reference to the fractal description of CB aggregafes, and by considering that, above a percolation threshold, highly branched aggregates can flocculate and form a secondary... 

In the eariy i 960s, Bueche was probably the first to consider carbon black as a part of a polyfunctional network (Bueche, 1961 1960). In his model, carbon black aggregates were chemically linked by chains and constitute what Medalia and Kraus describe as a giant multifunctional crosslink network (Medalia and Kraus, 1994). 

It must be noted that, apart the initial filler-filler network considerations of Payne and Kraus, fhe subsequenf models essentially recognized the fact—today widely accepted—that, except in very highly filled systems, direct filler-filler confacts are very unlikely. Explicitly stated by Aranguren et al., i in the case of silica-silicone sysfems however, it must be noted that successful BdR measurements imply that filler particles surface is completely wetted by the polymer. Therefore, contacts between filler aggregates can occur only Ihrough the polymer. The differences in the various models arise either from the description of the filled system or from the manner the local thermodynamics is treated. 

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