Strength of asphaltene clusters in heptane-diluted bitumen

The rupture strengths of individual asphaltene clusters in heptane-diluted bitumen were directly measured using a novel microcantilever technique. The majority of the ruptures occurred in the form of micron-sized fragments detaching from the original cluster (i.e. via ‘surface erosion’). The average rupture strength of the clusters was found to be ∼0.4 μN. Within the resolution of the present technique, the strength of reflocculation (i.e. adhesive force between two already-separated flocs) was undetectable.