It has previously been shown that liquid microstructures can be observed, in their natural state, by use of Environmental SEM (ESEM). In order to take full advantage of the ability to observe the dynamics of complex fluids, efforts are now being directed at developing in situ experimental methodologies. For example, we have recently shown that the coalescence of oil droplets in emulsion systems can be observed in real time. The purpose of the present study is to tackle the challenge of making EM observations of complex fluids under electrical stress (and ultimately electrical & mechanical stress combined) by subjecting particle dispersions to an electric field.
The technique of attracting charged particles to one of two electrodes (electrophoresis) is commonly used as a means of determining the nature and density of charges on such particles. Another technique, using uncharged particle systems, involves applying an electric field across a sample as well as, for example, a shear strain (electro-rheology).