Evaluation of oil-in-water emulsions with cationic–anionic surfactants mixtures for potential use in the oil industry

• The emulsifier properties of sodium oleate (NaOl)–hexadecyltrimethylammonium bromide (HTAB) aqueous mixtures were studied.
• The formation of O/W and W/O emulsions was explored and their properties were determined.
• It was found that all emulsions were stable on ageing and to temperature rise.
• The emulsions were destroyed by contact with quartzite stones.
• These mixtures have high potential applicability in the asphalt emulsification for pavement production or sand fixation.

The emulsifier properties of sodium oleate (NaOl)-hexadecyltrimethylammonium bromide (HTAB) aqueous mixtures were studied using different proportions of the surfactants. The formation of O/W and W/O emulsions was explored and their properties (viscosity, stability and droplets size distribution) were determined. The mixture with 0.75 mole fraction of HTAB without considering the solvent formed very stable and concentrated O/W emulsions, which were destroyed via heterocoagulation by quartzite sand. Thus, these mixtures have high potential applicability in the asphalt emulsification for pavement production or sand fixation.

Left: stones with crude oil emulsion. ×100, Crossed polaroids and 1 λ retardation plate intercalated, showing interference colours in the quartzite stones and sensitive pink of non-birefringent (water) medium. The black zones correspond to stones covered by hydrocarbon. Right: crude oil emulsion, unpolarised light. The emulsion used in both photos was diluted to improve visualization.Figure optionsDownload as PowerPoint slide