Electrophoresis

Electrophoresis is a separation technique based on differential transport of electrically charged species. The discovery of electricity was paralleled with an understanding of electrophoretic phenomena and consequently, this separation technique can be considered as classical.

Over the last two decades, all electrophoretic techniques have undergone an explosive growth, especially as concerns the analytical applications of the capillary version of electrophoresis. Nevertheless, there are only few publications describing the applications of this technique to the separation of charged particles. This can be explained by the fact that separation in electrophoresis is primarily based on differences in electric charge density which is inherently related to the size of the separated particles. As described in the section on HC, the effective size of the particles includes the thickness of the electric double layer which varies with the ionic force of the suspending liquid. This means that whenever the size separation concerns the particles in their natural environment, their effective size includes the electrostatic double layer and separation can be carried out by using electrophoretic transport processes. As the electric charge contains information on the nature of the particle surface, separation by elec-trophoresis is certainly a useful technique when used appropriately.

The general theory of electrophoretic separations applies to particle separations as well. This has been discussed above in respect to electric FFF. As the applications of electrophoretic techniques to particle separations are still very limited, it is impossible to review this technique as fully as for the other separation methods. Only one recent example, an interesting separation of polyaniline and silica particles, is shown in Figure 16.

Figure 16 Electropherograms of the individual polyaniline (PANI) and silica composite particles and of the separated mixture of both obtained by capillary electrophoresis.
Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

Get My Free Ebook


Post a comment