کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
612592 | 880702 | 2006 | 8 صفحه PDF | دانلود رایگان |
A model is proposed to account for the interaction energy and adhesion force between petroleum asphaltenes and metallic surfaces. It is assumed that the total molecule-surface interaction potential may be constructed through superposition of corresponding interactions with a relevant number of atomic layers forming the substrate and resorting to the Lindhard continuum planar potential (CPP) approximation, which requires only of knowledge of binary molecule-atom interactions. Molecular mechanics (MM) calculations are performed to generate the average binary interaction between the asphaltene molecule and an atom in the substrate, which in turn is represented by a parameterized analytical—physically sound—expression. The resulting CPP yields an analytical expression representing the interaction between the asphaltene molecule and each substrate layer. To validate the method, pilot calculations are performed for a sample asphaltene molecule with a fixed orientation relative to metallic surfaces of iron, aluminum, and chromium. Comparison between corresponding CPP and MM calculations for the asphaltene-plane (A-P) and asphaltene-substrate (A-S) interactions indicate reasonable agreement pointing to the adequacy of the CPP method to represent molecule-surface interactions. Also, the effect of a surrounding (i.e., solvent) medium is addressed with the use of a dielectric constant, ε, incorporated in the molecule-atom potential. Finally, a discussion is presented on the applicability of the method to generate an analytical universal expression for asphaltene-metallic wall interactions.
A model based on the continuum planar potential approximation is proposed to account for the interaction energy and adhesion force between petroleum asphaltenes and metallic surfaces.Figure optionsDownload as PowerPoint slide
Journal: Journal of Colloid and Interface Science - Volume 301, Issue 2, 15 September 2006, Pages 352–359