Monitoring and Predicting Emulsion Stability of Metalworking Fluids by Salt Titration and Laser Light Scattering Method

The prediction of emulsion stability is very important in the study, formulation, quality control, and technical service of metalworking fluids. Conventional emulsion stability test methods can be very time consuming. One quick method to determine emulsion stability is to titrate an emulsion with a salt solution until the emulsion separates. The salt (or electrolyte) concentration at which an emulsion starts to separate is called the critical coagulation concentration (CCC). The higher the CCC value, the more stable the emulsion. Another technique, called laser light scattering method, collects transmission and backscattering light by scanning emulsion samples with a laser. It is a very useful instrument to monitor emulsions and dispersions in kinetic studies of emulsion stability. The response of the laser light scattering method is very sensitive to any change in emulsion or dispersion stability. It has also been utilized in the quick selection of additives in semisynthetic metalworking fluids formulation. Presented at the STLE Annual Meeting in Las Vegas, Nevada, May 15–19, 2005 Review led by Jerry Byers KEY WORDS: Metalworking FluidsEmulsion StabilitySalt TitrationLaser Light Scattering Method Notes Presented at the STLE Annual Meeting in Las Vegas, Nevada, May 15–19, 2005 Review led by Jerry Byers