Effect of Ethylcellulose on the Rheology and Mechanical Heterogeneity of Asphaltene Films at the Oil–Water Interface

Autor: Kathryn A. Whitaker, Jodi M. Mecca, Tom H. Kalantar, Vincent Mansard, Christopher J. Tucker, Todd M. Squires, Ian Williams, Chih-Cheng Chang, Arash Nowbahar, Tzu-Chi Kuo, Adam K. Schmitt
Přispěvatelé: Department of Chemical Engineering [Santa Barbara], University of California [Santa Barbara] (UCSB), University of California-University of California, Department of Chemistry, University College London, University College of London [London] (UCL), Équipe Microsystèmes électromécaniques (LAAS-MEMS), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, The Dow Chemical Company, University of California [Santa Barbara] (UC Santa Barbara), University of California (UC)-University of California (UC), Department of Chemistry [University College of London], Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)
Rok vydání: 2019
Předmět:
Zdroj: Langmuir
Langmuir, American Chemical Society, 2019, 35 (29), pp.9374-9381. ⟨10.1021/acs.langmuir.9b00834⟩
Langmuir, 2019, 35 (29), pp.9374-9381. ⟨10.1021/acs.langmuir.9b00834⟩
ISSN: 1520-5827
0743-7463
DOI: 10.1021/acs.langmuir.9b00834
Popis: International audience; Asphaltenes are surface-active molecules that exist naturally in crude oil. They adsorb at the water–oil interface and form viscoelastic interfacial films that stabilize emulsion droplets, making water–oil separation extremely challenging. There is, thus, a need for chemical demulsifiers to disrupt the interfacial asphaltene films, and, thereby, facilitate water–oil separation. Here, we examine ethylcellulose (EC) as a model demulsifier and measure its impact on the interfacial properties of asphaltene films using interfacial shear microrheology. When EC is mixed with an oil and asphaltene solution, it retards the interfacial stiffening that occurs between the oil phase in contact with a water phase. Moreover, EC introduces relatively weak regions within the film. When EC is introduced to a pre-existing asphaltene film, the stiffness of the films decreases abruptly and significantly. Direct visualization of interfacial dynamics further reveals that EC acts inhomogeneously, and that relatively soft regions in the initial film are seen to expand. This mechanism likely impacts emulsion destabilization and provides new insight to the process of demulsification.
Databáze: OpenAIRE
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