Facility for Absorption and Surface Tension studies (FASTER)
The purpose of FASTER is to study the links between the physical chemistry of the droplets interface, the liquid films and the collective properties of an emulsion. One of the most relevant problems in emulsion technology concerns the control of emulsion stability.
For example, high stability and methods of long term stability prognosis are necessary for emulsions in foods, cosmetics, pharmacy etc. However separation of the two phases followed by destabilisation is required in waste water processing and oil recovery.
In both cases, the target can be achieved by introducing specific additives (like surfactants) which adsorb on to and modify the properties of droplet interfaces. Thus, it is clear that the adsorption of surface active molecules plays a fundamental role in emulsion science.
However, at present, the links between the physical chemistry of the droplet’s interface to the collective properties of an emulsion are only qualitative, so that the criteria used in industry are mainly empirical. FASTER is aimed at reducing this gap, which is today an important limitation of emulsion science and the further development of applications.
The FASTER experiment will address single and multiple interfaces, as affected by various surfactants. An important part of the programme aims at establishing links between emulsion stability and physic-chemical characteristics of droplet interfaces. Together with the FASES experiment, the team will generate a model of emulsion dynamics to be transferred to industrial applications.
The measurements will be carried out by applying periodic stimuli to a drop of liquid surrounding by another liquid (non miscible with the drop). The difference of pressure ΔP across the drop interface is calculated from the pressures measured in the two liquids. The frequency of the stimuli can be varied up to 1000 Hz and the amplitude up to 20% of drop diameter (diameter is about 0.8 mm). A camera will measure the profile of the drop. The exploitation of the results is carried out on ground.
There are two independent cells:
Cell#1 is composed of a drop of water in a paraffin oil matrix (70 cm3) in injection of surfactant Span 80 for about 1.9 cm3.
Cell#2 is composed of a drop of water in a hexane matrix (70cm3) in injection of surfactant C13DMPO and CTAB for about 1.9 cm3.
Last update: 12 April 2011