3rd German-Japanese Symposium on Nano Structures (OZ-10)

Our aerospace engineer Carsten Scharfenberg attended the 3rd German-Japanese Symposium on Nano Structures (OZ-10) in order to gain more information about ALICE, a recent alternative rocket propellant.

Here is Carsten´s report:
As I’m striving towards a bigger understanding on Alice propulsion technologies I attended OZ-10. This is a conference on recent advances in nano technologies organized by ZOZ GmbH – a german company that is a global player in nano materials.

The questions I hoped to get an answer to were: 1. Where to obtain nano aluminum? 2. If it is too expansive: How to produce it on my own? 3. How to deal with the powder itself? Especially: What safety requirements do I have to meet?

I got most of the answers but first of all I will cover the conference itself. It took place in the townhall of Wenden, which is a small town in the german countryside. I planned to arrive one day before the beginning of the conference. Alas, these plans were foiled by the storm “Xanthia” which caused damage to the railway power lines so I was forced to interrupt my journey for one night some hundred kilometers before reaching my destination. Nevertheless participants arrived from all over the world, especially from the far east (there were referees from Japan, Korea, Taiwan and China) – even the US Airforce was present. The main topics of this conference were: surface coatings and new high performance materials in mechanical engineering, in battery storage technologies and in hydrogen storage technologies. The absolute highlight of the conference – from my point of view – was the presentation of Zentallium (by Bayer MaterialScience) which is an alloy of aluminum and carbon nano tubes that is somewhat lighter than pure aluminum but as strong as steel.

I soon figured out that I was exactly in the right place to learn about nano aluminum as some of the attendants had lots of experience with this material. But I also had to hear that I severly underestimated the dangers of nano aluminum. Fresh aluminum surfaces are highly reactive. So if nano aluminum that was produced in an oxygen-free athmosphere is exposed to air it bursts into flames immediatly. This was known to me before, but what I did not know is that even nano aluminum with an oxide layer (so it is stable in air) can cause dust explosions. Also mixing the powder with water is dangerous if the oxide layer is too thin. So it is important to control the thickness of the oxide layer or alternatively the layer of some chemical deactivation agent.

Because of these dangers (and because of its short lifetime) it is not easy to buy nano aluminum. Big companies will only deliver to other big companies or governmental institutions. But it is possible to cheaply buy aluminum powder with a particle size of a few mircrons. This would be a good starting point for further milling to a smaller size. For this purpose we could build a simple ball mill on our own – the only challenge would be to figure out good milling parameters to actually achieve nano sized powder. Nevertheless safety measures have to be applied that can only be met by bigger institutions. So my next goal will be to find support by universities.

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