New Developments 1/1/17

A new generation of bubble pressure tensiometers, including BPA-2P and BPA-2S , as follow up developments of the excellent predecessors BPA-1P and BPA-1S , are available more...

New Books 1/1/17

Textbook “Dispersionseigenschaften - Stabilität, 2D-Rheologie, 3D-Rheologie“ This textbook contains the main fundamental knowledge on interfaces, colloidal systems more...

Latest events 1/1/17

2D-3D Rheology and Stability of Disperse Systems - User Workshop, May 8-10, 2017, Berlin-Schönefeld, Germany In May 2017 the 2D-3D Rheology and Stability of Disperse more...


Foams and Thin Films

Schaum Photo

Foam Analysis

The properties of foams formed from a certain surfactant or polymer solution cannot be forecasted from knowing the solutions surface properties. Even knowledge on respective foam films is not sufficient to know in advance the final foam behavior. Therefore, a direct characterization of real foams is essential for many applications. The principle of the FA is different from all other existing foam instruments. Although the foam generation is made in a standard way by pressing gas into a solution through a porous glass frit, the analysis of the produced foam is different from other instruments. The FA has two sets of sensors for measuring foamability, stability and drainage, one being an electric conductivity and the other an optical sensor. For transient foams which are not very stable, the instrument provides mainly the foam volume as a function of injected gas volume. For very stable foams the application of a partial vacuum to the foam column accelerates the drainage and the foam breaks down. This strategy make a quantitative analysis of a foam possible which otherwise would be stable even over days.
Thin Film Analysis

Thin films are the main elements of a foam or emulsions and therefore a characterization of their main properties, i.e. the thickness and the stability, is essential. The TFA provides such measurements. The thickness of foam films is measured by an interferometric method. The stability studies are done with the same and via a camera mounted to the used inverse microscope the process of film thinning, the appearance of black spots and black films can be recorded.