Properties of a two-dimensional asphaltene network at the water-cyclohexane interface deduced from dynamic tensiometry.
Static and dynamic tensiometries show that a newly prepared water/asphaltenated cyclohexane interface behaves as expected: the mean area occupied per asphaltene molecule is 2 nm2, and variations of interfacial tension and dilatational elastic modulus with time indicate that equilibrium is reached more slowly than that for usual surfactants. The use of the time/temperature superposition principle allows a detailed rheological study of a 2 day old interface of the same type which has reached equilibrium. It is found that the two-dimensional asphaltene network exhibits a glass transition zone, behaves as a gel near its gelation point, and is built by a universal process of aggregation.
Laboratoire des Fluides Complexes, UMR5150, Université de Pau, 64013 Pau Cedex, France. patrick.bouriat@univ-pau.fr
Patrick
P
Bouriat
Nabil
N
El Kerri
Alain
A
Graciaa
Jean
J
Lachaise