For the characterization of emulsions, essentially the evolution of drop size distribution with time includes all important information. Unfortunately, there is no commercial instrument that allows a general study of this behaviour. Main problem is the automation of such an analysis and the interference of sedimentation/creaming processes.
For foams the situation is quite different, as there are various commercial instruments on the market. Most of them are based on the procedure proposed by Ross and Miles, i.e. on the measurement of the breakdown of a foam column to half of its height. Some instruments also measure the drainage as function of time, however, mainly under not well defined conditions. The Foam Analyzer FA 2 produced by SINTERFACE is the first instrument that allows to determine drainage and stability of a foam under standardized conditions, i.e. as a function of applied partial vacuum. This provides the possibility of a quantitative correlation between foam and foam film properties and gives access to a deeper understanding of processes stabilizing and destabilizing foams.
The tool DBMM, the Drop Bubble Micro Manipulator, represents a unique opportunity to mimic the situation in foams and emulsions. Two bubbles or drops can be formed at the tip of a capillary, each, and then manipulated against each other, as it is the case in real liquid disperse systems. Even the asymmetric case of a bubble and a drop can be created (see also R. Miller and L. Liggieri (Eds.), Bubble and Drop Interfaces, in “Progress in Colloid and Interface Science”, Vol. 2, Brill Publ., Leiden, 2011, ISBN 978 90 04 17495 5).
SINTERFACE
