Interfacial properties of oil-in-water emulsions designed to be used as metalworking fluids

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Vol. 305; no. 1; pp. 112 - 119
• Main Authors: Cambiella, Ángel, Benito, José M., Pazos, Carmen, Coca, José
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-09-2007; Elsevier
• Subjects: Chemistry; Colloidal state and disperse state; Contact angle; Creaming stability; Emulsions. Microemulsions. Foams; Exact sciences and technology; General and physical chemistry; Metalworking fluids; Oil-in-water emulsions; Surface physical chemistry; Work of adhesion; Metalworking fluids; Contact angle; Work of adhesion; Oil-in-water emulsions; Creaming stability; Design; Stability; Oil water emulsion; Fluid; Creaming; Adhesion
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2007.04.049

The creaming stability and wetting behaviour of oil-in-water (O/W) emulsions, designed to be used as metalworking fluids, were evaluated. The influence of the emulsifier type and its concentration on emulsion properties (droplet size distribution, zeta potential, creaming stability, and contact angle or work of adhesion) was studied. O/W emulsions were prepared with 3% (w/w) base oil content and three different emulsifiers (anionic, non-ionic and cationic surfactants). The base oil was a mixture of a synthetic poly-α-olefin and a trimethylol propane trioleate ester, and emulsifier concentrations were close to and above their critical micelle concentrations (CMC). Experimental results show that emulsifier concentration plays a key role on the properties studied. The O/W emulsion characterisation leads to relationships between interfacial properties and lubricating behaviour, which seems to be controlled by the interactions between the oil droplets and metal surfaces.