ASPHALT COLLOIDAL TYPES DIFFERENTIATED BY KORCAK DISTRIBUTION

Asphalt in a colloidal context can be considered as a sol, sol-gel or gel type where in all three cases the asphaltene particle plays an important role. Usually the three colloidal types can be differentiated by refinery processes or by rheological properties. The aggregation or clustering of the asphaltene particles (or micelles) from sol to sol-gel and finally to the gel state with a fixed lattice can follow the stochastic process of fractal Brownian motion which can fit a hyperbolic (or Korcak) distribution. A test was carried out using the same mass of various asphalts of different colloidal types for floc formation with a series of n-alkanes (dispersion media) of increasing characteristic lengths. Results from floc formation studies indicate that the value of the size distribution for the gel type is small, is higher for the sol-gel type, and is highest for the sol type. On the other hand, the surface irregularities for all three types of asphalt do not have any correlation. These observed facts are consistent with principles based on the fractal approach.