Common Ground: Carbon and Corrosion
Development of the ability to refine and use metals has ever been a defining factor of human technological advancement. As soon as we discovered the advantages of tools that were more durable and could hold a sharper edge than stone or wood we started to dominate our natural predators and form civilisation. The advent of iron allowed efficient agriculture, steel provided protection and sturdier housing, whilst copper served as the infrastructure for the age of electricity.
Nowadays much of our modern industry would not function without the technological capabilities accessible through the use of metals. In Australia the mining industry alone contributes roughly 8.4% of the national gross domestic product annually, or $121 billion dollars in more understandable terms (Australian Bureau of Statistics, 2010). So it stands to reason that there is a lot of research being conducted into how to make the industry more efficient and reduce the costs of maintaining the infrastructure we put in place.
The next advancement in metallurgical science? Graphene.
Recently researchers from Monash University and Rice University published a paper in Carbon in which they revealed that a thin coating of graphene makes copper almost 100 times more resistant to corrosion than when untreated. This discovery is remarkable simply because all other techniques previously used to preserve copper (polymer coating, etc) have only ever yielded five or six times the protection.
Graphene (pictured right) is a single atom thick layer of carbon atoms that exhibits a number of stunning mechanical properties, including great strength and flexibility. A microscopic coating of graphene on a copper surface results in an invisible, highly durable shield that prevents access from corrosive oxidants in the surrounding environment. This has a staggering number of applications, ranging from safer underwater cable-laying to longer-lasting synthetic organ implants.
The research team used a process called chemical vapour deposition (CVD) at temperatures between 800 and 900 degrees Kelvin to apply the graphene layer. After application the copper sample was tested for corrosion susceptibility in a saline water solution, showing very little rust when compared to an untreated sample. Dr Banerjee, who performed many of the experiments drawn upon in the study, has stated that the group is currently investigating the viability of use on metals other than copper, as well as a means of applying the graphene coating at lower temperatures so as to increase market potential.
It would seem that, once again, one of the many forms of carbon-carbon structures has proved irrevocably useful in the development of more efficient industrial technologies. What other surprises does nanotechnology have in store?