A New Technological Era? [Archive] - Striper Talk Striped Bass Fishing, Surfcasting, Boating

Saltheart

02-24-2013, 01:51 PM

We worked with Pyrolytic carbon some 35 years ago. This is a carbon made by depositing decomposed carbon black on charged surfaces at very high temps.. the reason we like pyrolytic carbon was because it had very directional heat transfer properties. It has virtually no conductivity in the through thickness direction (between atom planes) but has the conductivity of copper in the in plane directions. Essentially heat flows to atoms in the same planes but not to atoms in the planes above and below them.

I then got into what is called highly oriented pyrolytic carbon. In this process we took regular PVD pyrolytic carbon and hot pressed it at temps of about 3000C to "iron" the wrinkles out of the pyrolytic carbon layers. this method made materials with very flat layers of carbon atoms. these flat layers were used to make X-ray monochrometers. You shoot Xrays of varying wavelengths into the highly oriented carbon layers but only very specific wavelengths interact well with the specific layer spacing thus producing large amounts of X-rays at a specific wave length.

Now heres the funny part. The pieces we hot pressed would have non oriented carbon layers along the outside surfaces and edges because of the uneven way the starting samples were cut. We got rid of these unoriented carbon layers by peeling them off using scotch tape. These single atom layers were simply throne away until we got to a nice even surface of highly oriented layers , then the material was tested using X-rays to confirm they would function as monochrometers.

Well anyway , it is now known that the stuff we peeled off using scotch tape and threw away as waste were in fact single layer Graphene. This (the making of graphene) all happened 35 + years ago. We just didn't know what we had. :)

Yes the Mil and everyone else on the planet it interested in single layer carbon sheets as shown in the video. They are also interested in non planer structures of carbon like long fibers and even what are called carbon dots (3D , 2D and 1D structures where the through thickness dimension is a single atom layer thick) . There is also a big interest in these structures as well as the planer graphene shown in the video if they can be deposited on certain substrates as well as just on their own. Deposited on substrates they can form Quantum Wells and Quantum Dots. Very interesting area of nano materials.