Wide Angle X-ray Scattering as a Technique of Choice to Probe Asphaltene Hierarchical Structures.

Bitumens are composite systems extensively used in road pavements. Due to their complex nature, a rational understanding of the relationships between composition, structure and performances of these materials is still far from being achieved, so research attempting to shed more light in this field is required. Here, we exploit Wide Angle X-ray Scattering (WAXS) as a technique of choice to shed light on the bitumen structure at different length scales. Diagnostic fingerprints, characterizing the WAXS profile, are correlated to specific Bragg distances which can be reasonably attributed to the molecular and supramolecular aggregation taking place at various levels of complexity leading to the formation of hierarchical structures. Due to the inherent instability of these materials some indications are given to obtain reliable structural data.