What you may think of as an irritating, orange-red rust gradually eating away at metal surfaces, is actually just one form of a multipurpose tool with life-saving capabilities. Rust is really just iron oxides. Interestingly, less is more when it comes to the iron oxides. Some of these uses require nano-sized particles of iron oxides; particles no larger than 100 nanometres in width.
Researchers at NMMU’s Centre of Excellence for High Resolution Transmission Electron Microscopy (HRTEM) are hard at work to both synthesise and analyse iron oxide nanoparticles, for a range of applications. Matthew Coombes, PhD student at the Centre for HRTEM, sums up the uses of iron oxides: “From pigment dyes, catalysis and the removal of heavy metal ions from water, to biomedical and sensing applications and magnetic storage devices, iron oxide nanoparticles have found a place in almost every possible area of application.”
As just one example of the huge scope of possible applications of rust: consider for a moment magnetite, a type of iron oxide (ratio of three iron atoms and four oxygen atoms). When in nanoparticle size, it becomes superparamagnetic. This means that it may be really strongly magnetized when placed in a magnetic field, making it easily detectable by a method such as Magnetic Resonance Imaging (MRI). MRI Scanning is an essential diagnostic tool used by the medical profession today that allows us to visualise structures in the human body. By surrounding the magnetite nanoparticles with chemicals or drugs that help the nanoparticles to travel to a specific organ or tumor, and injecting them into a body, you can “stain” the area that you want to examine. This allows us to visualise diseased or damaged organs within the human body.
As to side effects, you needn’t worry about any form of poisoning from the nanoparticles – they are non-toxic to humans.
And the price tag for so much functionality? With iron being the fourth most abundant element on earth, they are relatively cheap to produce.
Writers: Crystal Clitheroe & Matthew Coombes