Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by blane.c, Oct 2, 2019.
Webinar tue. the 9th.
I expect the webinar is a sales pitch and will be way over my head, but it could be interesting.
A blurb from another site:
FWIW, a UK site lists the price of the graphene powder as about $185 per kg, but at the mixing rate specified above (0.17% by weight), 1 kg of the stuff should make almost 600 kg of finished CF/epoxy laminate. So, a few small airplanes. They sell samples of 250g for about $90, which would be enough for approx 330 lbs of final laminate at the above listed proportions.
Also, it would be very wise for anyone considering messing with this stuff to read up on nanoparticles and the hazards they might present. There's some evidence that the normal defenses our bodies employ are not effective at filtering out/getting rid of these unnaturally small particles, and that they can cross many biological barriers and remain inside organisms. Even particles that are not chemically active can cause mechanical damage to various structures, possibly including DNA. Most filters normally found in shops cannot protect against nanoparticles. Anyway--do your research and be aware that there are big gaps in our understanding of the health impact of some of these materials. Here's a sample of some of the research.
Geezus - how the hell do you work safely with the stuff?
Carefully wet it and keep it wet.
Can it be pre mixed with one part of the resin before purchase? Or is it still dangerous at that stage?
I really don't know much about it. The vendor sells it as a powder and as a water-borne paste. Obviously, of those two, we'd need the powder.
There may be some effective industrial hygeine protocols for working with it (maybe work outside with a positive air pressure mask, etc). Yes, perhaps you could send them resin and have them mix the graphene in, then add your hardener as needed. (And the product listed at one of the links on my earlier post is some sort of epoxy resin with graphene mixed in). But, mailing epoxy back and forth is also problematic. And, though I'd assume it stays well stuck to the cured epoxy, I'd want to verify that before doing any sanding, drilling, filing, etc.
The industrial safety and regulatory environment surrounding the use of nanoparticles is, IMO, too lax. We have good reason to believe they may possibly pose unique and not fully understood health and environmental challenges, but nobody has taken steps to restrict their use. It reminds me of the early days of industrial use of radioactive substances, though at this point we have no good excuse.
Sorry, this is a bit off topic.
In that Graphene Star link they sell resins with the Graphene in them in their products page.
Is anyone planning on watching the webinar? Its on at 2am here in Australia so I'll be giving it a miss.
Yes I plan to do so.
Please provide a summary/report if you can.
Stuff doesn't look too dangerous to work with
Well ... he lugs an O2 bottle with him wherever he goes now, and his liver is highly conductive, but othervthan that, no issues !
That's it - and he goes all hyper during electrical storms!
Oooh, invisible health damage, the kind your insurance company love's.
I still think it is interesting stuff.
Yes, I do, too. It seems a bit too much like magic ("psst--spend $100 for 8 oz of this powder and you'll have enough to do your whole plane. You can reduce the amount of CF in your layups by 30%--saving a lot of weight and $$ in carbon fiber and epoxy"). Still, there could be something to it. I'd like to be sure there are no long-term issues, and maybe the best way to know about that is to see if the big airplane makers are using it.
Maybe it is in boats, atv's or other stuff?
It could be, but airplane design from major manufacturers is very conservative. That's what I want. If an ATV's fender develops a crack in 20 years, it's not going to bring down the company. If the stabilizers on Boeing's 7X7s start snapping off--that's serious.
Hereby the summary of the graphene webinar, orginised by The Graphene Council, presented by Terrance Barkan.
The beginning of the webinar covered the definitions of graphene. Graphene is defined as a two dimensional form of carbon, just a single atom thick bonded in a honeycomb shape. Different forms of graphene exist in which the difference is the amount of layers present. Varying from one to 10 atomic layers thick depending on the definition used.
Even though the base material, graphite, is cheap the price of grapene is pretty expensive per kilogram. Between 100 - 2000$/kg for 3 to 20 atom layers thick. This group of graphene should be commerically available. The single sheet graphene is currently extremely expensive, the slides indicated even up to $500,000/m^2. For composite applications the 10-20 range would be most usefull.
The benefit is that only little amount by weight percentage has to be used to show a significant effect. Mostly 0.5% weight fraction was mentioned. This reduces the total cost to more manageble amounts.
Graphene has an extremely large surface area; roughly 2300/m^2 per gram of graphene. Hence it remains very easily airborne this poses health risks. It was stressed that contact should be prevented. The same PPE used for other nano materials should be used for graphene as well. Especially the powder form is dangerous and it should only be handled by the production facility. Sanding and cutting of materials in which graphene is embedded should be no issue at all.
40 major application areas were identified of which composites is one of the larger sectors, the material has many usefull properties:
It is extremely strong and stiff, can be 97% transparent when a single layer thick. It increases conductivity both electrically and thermally. It can add strength, flexural strength (+20%) , elongation (+12%) (0.5% graphene added to polyester glass rods by http://nanoxplore.ca/) . Impact toughness (+50%), lighter frame (-30%) increased interlaminar shear stress (+70%) for the Dassi Interceptor Graphene bicycle frame. Reduced mass from 950 to 750 grams. It was stated that with nylon plastic even improvements of 400 to 500% were found, not yet officially published. (I guess without fibres this is). Used to improve lightning strike resistance on a carbon fibre plate (6x through thickness improved conductivity) which prevented punch through compared to the non graphene infused panel. Usefull in both thermosets and thermoplastics (all kinds), and many many more other applications.
Niagara Water infused graphene in PET water bottles and was able to obtain a FDA approval for food safety (or still in the process, not sure). https://xgsciences.com/materials/polymer-composites/thermoplastics/
It was stressed that the type of graphene used, should be tuned to the application to have the best result for the required properties.
About 300 companies outside China work with graphene, compared to 5000 ish in China (heavily subsidised).
Currently about 6000 metric tonnes are produced per annum, There are no large barriers preventing large scale ramp up to meet future demands.
Recording can be found here:
Many thanks Soaring Eagle - great report!
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