Surface Interactions between Water-in-Oil Emulsions with Asphaltenes and Electroless Nickel–Phosphorus Coating

Abstract

Surface interactions between emulsion drops and substrate surfaces play an important role in many phenomena in industrial processes, such as fouling issues in oil production. Investigating the interaction forces between the water-in-oil emulsion drops with interfacially adsorbed asphaltenes and various substrates is of fundamental and practical importance in understanding the fouling mechanisms and developing efficient antifouling strategies. In this work, the surface interactions between water drops with asphaltenes and Fe substrates with or without an electroless nickel−phosphorus (EN) coating in organic media have been directly quantified using the atomic force microscope drop probe technique. The effects of asphaltene concentration, organic solvent type, aging time, contact time, and loading force were investigated. The results demonstrated that the adhesion between water drops and the substrates was enhanced with higher asphaltene concentration, better organic solvent to asphaltenes, longer aging time, longer contact time, and stronger loading force, which was due to the growing amount and conformational change of asphaltenes adsorbed at the water/oil interface. Meanwhile, the adhesion between the water drop and the EN substrate was much weaker than that with the Fe substrate. The bulk fouling tests also showed that EN coating had a very good antifouling performance, which was in consistence with the force measurement results. Our work sheds light on the fundamental understanding of emulsionrelated fouling mechanisms in the oil industry and provides useful information for developing new coatings with antifouling performances.

Debunking the Impact of Salinity on Crude Oil/Water Interfacial Tension

“…26 Also, the late decay region is affected by reordering (i.e., repacking or conformational relaxation in other works 29 ) of the preadsorbed surface-active materials at the interface in order to minimize the exposure to the polar water medium. 25,58,59 Furthermore, Figure 1a,c shows different starting points for the oil/water interfacial tension curve versus time. The difference between the first point on the dynamic interfacial tension curves can be attributed to the diffusion-controlled kinetics as well.…”

“…Still, investigating the oil/water interfacial tension in the presence of salts within the aqueous phase is essential, when the role of fluid–fluid interactions has been increasingly highlighted by recent advances in new technologies of interface characterization. , Crude oil/water interfacial tension measurement is a primary tool to provide important information about the oil/water interface and the impact of several fluid–fluid interactions each of which would lead to LSE. A principal surface-active material within the crude oil phase has been reported to be asphaltenes that can diffuse into the oil/water interface and form a rigid solid-like interface. , Formation of a rigid interfacial film by asphaltenes at the oil/water interface has been recognised as the main mechanism of stable water in crude oil (W/O) emulsions.…”

Anti-Oil-Adhesion Property of Superhydrophilic/Underwater Superoleophobic Phytic Acid-FeIII Complex Coatings

“…In 100 and 300 mM NaCl solutions, the approach force profiles of interaction between the oil droplet and surface are purely repulsive. The jump-in behavior was observed in the approaching force profile of the PAFC 1:3 -1 coating in 500 mM NaCl solution (inset of Figure C), implying the droplet attachment on the substrate. ,, It was noted that the oil droplets could still be lifted from the PAFC 1:3 -1 coating under the probe drive; meanwhile, a strong adhesion force of 28.38 nN was measured. The PAFC 1:3 -4 coating exhibited lower adhesion forces at all salinities, and no jump-in behavior was detected between oil droplets and the PAFC 1:3 -4 surface.…”

“…The AFM droplet probe technique was applied to directly measure the interaction between micrometer-sized n -tetradecane droplets and surfaces in aqueous solutions to elucidate the surface properties and microscopic oil-adhesion mechanism of PAFC coatings. ,− To accurately analyze the effect of surface properties on the underwater adhesion behavior between oil droplets and PAFC coatings, the adhesion force between oil droplets and surfaces was measured with a quasi-static condition (a piezo driving rate of 1 μm/s). For the quasi-static situation, DLVO forces play a decisive role in the interaction between droplets and surfaces, while the effect of dynamic water forces is negligible. , Driven by the piezoelectric ceramic, the oil droplet approaches the surface and retracts after reaching the trig threshold of 5 nN.…”

Probing the Interaction Mechanism between Benzohydroxamic Acid and Mineral Surface in the Presence of Pb2+ Ions by AFM Force Measurements and First-Principles Calculations

“…Atomic force microscopy (AFM) has been widely used for measuring the surface forces and investigating the interaction mechanisms of various material systems at the nanoscale. − In our recent study, AFM was employed to probe the interaction forces between model oleic acid molecules and fluorite surfaces of different orientations both in air and in aqueous solutions under multiple pH conditions. , AFM force measurements were also conducted to detect the interaction forces of model octyl hydroxamic acid (OHA) molecules with different oxide minerals, including wolframite, calcite, and quartz. , One prerequisite for these AFM force measurements between organic molecules and material surfaces is to design and develop model molecules that could be self-assembled on AFM tips, thereby exposing the desired terminal functional groups same as the targeted organic molecules. In previous studies, 16-mercaptohexadecanoic acid was used as a model molecule for oleic acid, while S -[(2-hydroxyamino)-2-oxoethyl]- N,N -dimethyl-dithiocarbamate was synthesized as a model molecule for OHA. ,, …”