02149nab a2200205 4500 20260520002824.0 260224s2009 xxu Relation betweenn nanoscale structure of asphaltene aggregates and their macroscopic solution properties sep./oct. 2009 17/06/2010 ; 17/06/2010 12 p. ; 617-628 Transcripción del resumen del autor. Some peculiar macroscopic properties of crude oils are ascribed to their densest, heaviest and most polar fraction: the asphaltenes. The comprehension of the origin of these properties relies on a fine structural description of these fractions. We present a nanometre length scale characterisation of asphaltene solutions based on new or recent scattering experiments (X-rays and neutrons) from which structural parameters of asphaltene aggregates (Mw, Rg and A2) are extracted. The mutual dependence of these parameters is consistent with a mass fractal model. This single model accounts for very different macroscopic solution properties. Solvent trapping in fractal aggregates enables asphaltene solution viscosity to be fully predicted as a function of asphaltene concentration. Asphaltene adsorbs at liquid-liquid and liquid-solid interfaces as a monolayer whose thickness is of the same order of magnitude as the characteristic size of the asphaltene aggregate in bulk. Adsorption isotherm analysis, neutron reflectivity experiments and contrast-matching SANS allow one to highlight a densification of the asphaltene aggregates in the adsorbed layer in comparison with the solvated aggregates in bulk. Finally, the repulsive/attractive interaction balance between aggregates can be related to the relative stability of water in oil emulsions and to the stability of hydro-conversion effluents. This structure/property approach allows one to assess the mass fractal model which is discussed. 5 Oil and Gas Science and Technology 64 ARTICULO Barré, L. 12689 Jestin, J. 42998 Morisset, A. 42999 171200 171200 0 0 0 0 239019 BAAB BAAB 2026-03-05 200046058 0 200046058 2026-03-05 15:13:34 2026-03-05 ARTICULO