“Peanut Particles” as Microscopic Transport Systems

http://phys.org/news/2013-11-peanut-particles-micro-scale-factories.html

This article describes “peanut particles,” colloidal particles made from hematite, which could be used on microscopic “assembly lines” to transport molecules. The particles operate using several chemical properties that we have discussed in class. Hematite, an iron oxide, is magnetic (due to unpaired electrons in its outer orbitals), so researchers can move the particles by manipulating magnetic fields. Our recent NMR labs have illustrated the importance of magnetic fields in identifying chemical compounds, and this experiment demonstrates another use of magnetism in chemistry. Secondly, the researchers used the natural decomposition of hydrogen peroxide into water and oxygen to create osmotic pressure, which propels the peanut particles. The decomposition of hydrogen peroxide is a spontaneous process; the entropy of the system increases since the products contain more moles of gas than the reactants. Finally, changes in pH determine the attraction or repulsion between the peanut particles. All of these processes, at least at the basic level, have been covered in class.

I found this article interesting because of its relevance to our class material. Although these researchers are going much more chemically in depth in their work than we are in class, the basic underlying principles they rely on, including paramagnetism, entropy, and pH, are the same as those we discuss, illustrating the way that chemical topics build on each other. On the other hand, I would have been interested to know more about the possible applications of these peanut particles. The article described how the particles could be used to transport cargo, but it didn’t really explain what the possible uses of microbiological cargo transport could be.

Submitted by: Amanda Jack