Cerium Oxide as a biocide

It's been a few weeks since a new use for rare earths was published.

http://www.thestatesman.com/supplements/taking-a-leaf-out-of-nature-s-book-1490737594.html

Taking a leaf out of Nature’s book

• S Ananthanarayanan | New Delhi
  
  March 29, 2017 | 03:17 AM

Seawater, like the rest of the environment, is teeming with bacteria and other miniature life forms. Stationary structures like buoys, off-shore platforms or aquaculture nets get quickly covered by colonies of barnacles, bacteria and algae. The hulls of ships are known to get overgrown with organisms within a few months of an overhaul. The higher drag that ships experience has been reported to increase fuel costs by 28 per cent.

Most things we handle like packaging material, door handles, keyboards, pipes that bring us water, also get covered with bacteria, which lead to the spread of infection. It is the same in medical practice and patients in treatment run serious risks of contracting bacteria from devices like cathe-ters or tubes that deliver blood, saline or drugs.

The scale of the problem led Karoline Herget, Patrick Hubach, Stefan Pusch, Peter Deglmann, Hermann Götz, Tatiana E Gorelik, Il’ya A Gural’skiy, Felix Pfitzner, Thorben Link, Stephan Schenk, Martin Panthöfer, Vadim Ksenofontov, Ute Kolb, Till Opatz, Rute André and Wolfgang Tremel, of the Johannes Gutenberg University, Mainz, the Taras Shevchenko National University of Kyiv, Ukraine and at the laboratories of the giant chemical company, BASF, at Ludwigshafen, to seek a solution in the way seaweeds, which spend their lives in sea water, remain free of bacterial fouling. The team reports in the journal, Advanced Materials of the development. It is building on earlier work by Tremel and colleagues, of a material that simulates the working of natural enzymes to inhibit the build-up of algae and bacteria on plant surfaces.

The team hence synthesised nanorods, 20 to 100 millionths of a metre long and 10 millionths of a metre wide, and embedded the nanorods in paints to be used in panels immersed in marine water. “Steel panels with cerium oxide coatings can be exposed to seawater for weeks on end without becoming covered by bacteria, algae, molluscs, or barnacles. Reference samples with conventional water-based coatings develop massive fouling over the same time period,” says a press release by the Johannes Gutenberg University.