I would have to look back but it is not much compared to the payback.
At the moment it is all about the "quality" of graphene. The cost factor will come in time.
I just read this great piece on ADVFN
So I have gone through the data in the article "the Worldwide Graphene Flake Production" and I am going to share the highlights for those who can't access the content or are too lazy... I mean busy
First, the authors have characterized "graphene" flakes from 60 UNNAMED producers worldwide, so we do not know whether Versarien's Nanene or GNP-HP are amongst these...
What we do know is the following:
-Out of 36 companies, no company is currently producing above 50% graphene content... only one company produces 40-50% graphene flakes, and 2 companies produce 30-40% graphene. The majority of the companies are producing less than 10% graphene content, so they are essentially 90% graphite.
- Most companies do not control at all the distribution of the number of layers of their flakes, all samples actually contain some graphene, but it is often lost in a sea of graphite. So some companies claim to be making graphene when their product is actually 1% graphene...
- only 17 products have a carbon content of 90-100%, all the other samples had less than 90% carbon. They do not differentiate within the 90-100% range, although 99% carbon is probably way better than 92%...
Similarly, only 7 samples had more than 50% sp2 bonds (crystalline graphene should have 100% sp2 bonds).
So most products are heavily contaminated.
-Then the lateral size... only one company with an average lateral size of 11-100 microns, 1 company in the 5.1-7 microns range, and 2 companies in the 3.1-5 microns range. 85% of companies produce a lateral size under 2 microns, which is essentially useless for mechanical properties according to many previous posts although I have not checked that myself.
They do highlight the fact that they haven't tested all the products out there and they may have missed some high-quality graphene platelets on the market.
Also, I find it really annoying that they haven't linked the various properties that they have measured, what I mean is they do not explain whether the sample with a lateral size of 11+ microns is one of those with a high graphite content, or whether it has a high or low carbon content... They could have been a lot more transparent in the way they presented the data! and they could have named the producers as well.
Bottom line is most of the graphene companies out there produce either fake graphene which is essentially graphite and/or flakes with a tiny lateral size and/or heavily contaminated flakes.
Now what we know about Nanene, according to its data sheet:
- 60% under 5 layers
- 90% under 10 layers
- 98% carbon purity
- lateral size under 10 microns
So according to this data, Nanene was not one of the products tested in this paper and is superior to all the graphene platelets that were tested.
But could it be that it is one of them? in which case probably one of the 3 samples only that contained 90% flakes under 20 layers (the issue I have with data transparency in the article shines here, under 20 layers could be 11 or could be 19, huge difference!!). But if it is one of them then there is still room for improvement, especially regarding the graphite to graphene yield and the sp2 hybridisation (related to contamination and defects).
