The Effect of the ζ Potential on the Stability of a Non-Polar Oil-in-Water Emulsion

• Published in: Journal of colloid and interface science 1996-12, Vol.184 (2), p.433-436
• Main Authors: Stachurski, Józef, MichaŁek, MieczysŁaw
• Format: Article
• Language: English
• Subjects: Chemistry; Colloidal state and disperse state; Emulsions. Microemulsions. Foams; Exact sciences and technology; General and physical chemistry
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1006/jcis.1996.0637

The aim of this work was to investigate the electrophoretic properties of emulsion droplets of aliphatic hydrocarbons containing C6to C16carbon atoms in hydrocarbon chains. As it was observed experimentally, the emulsion droplets of hydrocarbons C9to C16revealed a completely different course of changes of the ζ potential due to pH than then-alkanes of shorter hydrocarbon chains (C6to C8). They revealed a negative value of the ζ potential, lower by almost twice. The ζ potentials of emulsion droplets of then-alkanes, fromn-nonane ton-hexadecane, do not practically depend on the length of the hydrocarbon chain but, first of all, on the pH of aqueous solutions. The cause of the origin of the negative zeta potential ofn-alkane droplets lies in the selective adsorption of−OH ions, causing the gathering of the excessive negative charge at the oil–water interface. As it was assumed, the stability of oil-in-water emulsion droplets in the solution, i.e., the time of collection of liquid hydrocarbons C6H28on the surface of aqueous solutions, is the criterion of the life of emulsion droplets ofn-alkanes. The observations indicate a close correlation between the emulsion droplets stability of the tested aliphatic hydrocarbons in water and the value changes of the ζ potential.