AGGREGATION AND COAGULATION OF ASPHALTENES IN OIL FILM: PHYSICAL CHARACTERISTICS OF SURFACE DEPOSIT PRODUCTS

The relevance of the discussed issue is caused by the practical significance of studying aggregation of asphaltenes in oil film and determining the dimensional parameters of micro-and nanostructures of the deposited components. The previously conducted researches on deposition of asphaltenes from solutions of oil in n-hexane were not associated with the study of such objects as (dam oil n-hexane vaporsh. For this reason, the studies on development of methods for imaging coagulation and deposition of asphaltenes in oil films are of special scientific interest. The main aim of the study is to get the experimental data on aggregation of asphaltenes of film oil on the surface of a solid body in terms of destabilizing effects of n-hexane vapors; to study the morphology and determine the dimensional parameters of the precipitated asphaltenes. The methods used in the study. The authors have applied microvideo for detecting fast processes on the surface of oil films in n-alkanes vapors. Coagulation and deposition of asphaltenes in oil films were visualized using digital optical microscopy. The morphology and structural parameters of the precipitated asphaltenes were determined by atomic force microscopy (AFM). The results. It was ascertained that in the system << oil film n-hexane vapor >>, the aggregation of asphaltenes is preceded by local deformation of the film surface in areas of adsorption and penetration of saturated vapor of n-hexane into the oil phase. Typical movement of microparticles of asphaltenes in oil film recorded by the digital optical microscopy can be explained by disperse medium circulation. Using the atomic force microscopy method the authors determined the dimensional parameters of the precipitated asphaltene structure. The paper demonstrates the possibility of applying the atomic force microscopy for imaging resins and oils in adsorbed state. The results show that oil asphaltenes deposition on a solid body surface is in nonequilibrium conditions. The research can be used to develop the integrated methodology to study aggregation and coagulation of asphaltenes in oil films using digital optical microscopy and micro video, and to study the morphology of precipitated asphaltene nanostructures by the atomic force microscopy.