Models of an asphaltene aggregate and a micelle of the petroleum colloid system

Abstract

Using recent proposals for the hypothetical structure of an average asphaltene molecule and the results of determining the dimensions of asphaltene molecules and aggregates, a model of the asphaltene aggregate (nucleus) was constructed. It contains three or more layers, each made up of four asphaltene molecules. The asphaltene nucleus is held together by van der Waals forces which act between numerous hydrogen atoms, the interaction of π-π bonds of the planar parts of the asphlatene molecule, and hydrogen and ion-dipole bonds. The form of an irregular rectangular “brick” for the asphaltene molecule was used to build the model. It contains vertical cavities the dimensions of which enable the containment of metal ions and/or salt molecules. By assigning quasi rectangular forms to the resin molecule, a model of the petroleum colloid system micelle was constructed. In the model four asphaltene molecules which build a layer, are surrounded by seven resin molecules. The presentation of the asphaltene nucleus in the form of a brick building could make the three-dimensional computer analysis of possible structures much easier. 3- and 21-layer micelles have been constructed, and the possible positions of metal ions and salt molecules have been shown.