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Indexed by:期刊论文

Date of Publication:2017-09-01

Journal:JOURNAL OF MOLECULAR LIQUIDS

Included Journals:SCIE、EI、Scopus

Volume:241

Page Number:1069-1078

ISSN No.:0167-7322

Key Words:Foam stability; Oil-water emulsion; Mixed polymer/surfactant emulsifier; Silica nanoparticles; Equilibrium surface tension; Bubble size

Abstract:The foam stability of oil-water emulsions stabilised by various surface-active components at high temperature is one of the major problems facing foam-flooding petroleum recovery because of foam instability at the high temperature underground. In this paper, foams stabilised by sodium dodecylbenzene sulfonate (SDBS), polyethylene glycol (PEG) and silica (SiO2) nanoparticles in water-liquid paraffin (50%/50%) emulsions at temperature from 20 to 80 degrees C were studied. Foam properties such as foam stability over time at different temperatures, equilibrium surface tension, and bubble morphology (bubble size) were determined by surface tension measurements and inverted fluorescence microscopy. High foam stability was demonstrated by emulsions of SDBS, PEG, SiO2 nano particles, and liquid paraffin from 40 to 80 degrees C. The properties of the PEG-SDBS foams improved when SiO2 nano particles were added. Foam stability increased when SDBS was adsorbed on the bubble surface as the bubbles did not rupture easily in the liquid phase in the presence of SDBS because of the formation of closely packed small bubble droplets bridging between neighbouring large bubbles, which were separated by long chain polymers. This phenomenon may arise because the SiO2 nanoparticles formed networks and were adsorbed with surfactant molecules on the bubble surface of the oil-water emulsion, causing the foam inflexibility to increase and thus improving aqueous foam stability at high temperature. (C) 2017 Published by Elsevier B.V.