A Convenient Apparatus to Determine the Zeta Potential of Grains by Electro-Osmosis

International audienc

Zeta Potential of Air Bubbles in Solutions of Binary Mixtures of Surfactants (Monodistributed Nonionic/Anionic Surfactant Mixtures)

International audienc

Cytoplasmic wax ester accumulation during biofilm-driven substrate assimilation at the alkanewater interface by Marinobacter hydrocarbonoclasticus SP17.

International audienc

Effect of the water-soluble indigenous crude oil surfactants on the w/o interfacial properties and emulsion stability

AFFInternational audienc

Characterization of Crude Oil Interfacial Material Isolated by the Wet Silica Method. Part 2: Dilatational and Shear Interfacial Properties.

International audienceTo better understand the water-in-oil (w/o) emulsion stability problem, the interfacial material (IM) of four different crude oils was isolated using the wet silica method and analyzed by different techniques. In part 1 (10.1021/acs.energyfuels.6b02899), we used gel permeation chromatog. to analyze the mol. size distribution of S-, Ni-, and V-contg. compds. Here, we report the use of dilatational and shear interfacial rheol. to analyze the interfacial properties of the IM films. In the second part of this series of papers, it is shown that the wet silica isolation method is reproducible and concs. the most surface-active mols. present in crude oils. Shear interfacial rheol. results showed perfect correlation to emulsion stability; stronger mech. properties lead to more stable w/o emulsions. Dilatational rheol. revealed that successive IM exts. from a crude oil are composed of mols. that behave increasingly like insol. surfactants that aggregate at the w/o interface. Lastly, shear rheol. expts. with dild. IM and dild. crude oil showed some differences that were ascribed to a different partitioning between the bulk and interface

Characterization of crude oil interfacial material isolated by the wet silica method

COMInternational audienc

Characterization of Crude Oil Interfacial Material Isolated by the Wet Silica Method. Part 1: Gel Permeation Chromatography Inductively Coupled Plasma High-Resolution Mass Spectrometry Analysis

The interfacial material (IM) from four different crude oils with different capabilities to form stable water-in-oil (w/o) emulsion was extracted with the wet silica method and analyzed by different techniques. In the first of a series of papers, we report the use of gel permeation chromatography inductively coupled plasma high-resolution mass spectrometry (GPC ICP HR MS) to analyze the size distributions of sulfur-, vanadium-, and nickel-containing compounds present in the IM. The analysis of replicate samples demonstrated the reproducibility of the wet silica extraction method, and successive extractions of the same crude oil concentrated larger and more insoluble IM aggregates containing S, V, and Ni. The analysis of the IM from different crude oils revealed that there is a similar, selective adsorption of high-molecular-weight compounds containing Ni and V at the w/o interface. Conversely, the sulfur profiles for all of these IMs were unique, and given their widely varying ability to stabilize emulsions, it suggests that these species may play a role in the stability of water-in-crude oil emulsions