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Old 3rd April 2009, 06:55 PM   #56
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Originally Posted by ElMondoHummus View Post
Sunstealer, I'm not positive this is paint. Then again, I'm not sure if there are classes of silicon based paints that are not soluble in methyl ethyl ketone (MEK).

There are other classes of anticorrosive coatings. I wonder if that's what this could be that. I simply don't know enough about the composition of the towers to know if any were applied to the steel.

BTW, while I have you here: On p. 13 of this new paper, there's some X-EDS spectroscopy that Jones et. al. is claming demonstrates that the FE to O ratio is 2 to 3, therefore validating the notion that this is indeed Fe2O3. I haven't gone back to look at your posts regarding interpreting EDX, so I'm not sure how solid this identification is (my undergrad work had me do CGs and NMRs, and that was years ago, so I don't even remember much of that). Does that specific point seem solid to you?

They haven't provided any figures or calculations nor said what the software package is for converting their qualitative data (the spectra) to a quantitative one which will then give you actual compounds present. So no they can't just say that the ratio is 3:2 but I'll check when I've got more time to digest the paper because they are clearly looking at proving aluminium powder iron III oxide. TBH if it's unreactive thermite then with the SEM they should be able to pickout individual particles of Aluminium and iron III oxide, instead we see some form of iron oxide and a spectra with Aluminium, Silicon and Oxygen in with distinct crystollographic shapes and they claim the Oxygen is on the surface of the aluminium (how they tell this I don't know).

I was expecting some proper analysis using XRD (x-ray diffraction) because this would then definitely give the compounds present and their amounts and prove once and for all what the chips are actually made of. They keep using EDS and whilst the graphs look pretty and fool those who don't have any experience they simply cannot be used for a quantitative analysis so their claims are pretty poor.

I'm actually interested in Figs 24-27 and Fig 8. On first looking at fig 8 along with the spectra the dark crystals and platelets looks like Kaolin/Kaolinite. Whilst the smaller brighter crystals look a bit like SiO2 but they have EDS data showing predominantly Fe and O in those regions.

Note how in fig 25 they pick up Titanium which will almost certainly be TiO2 which is a whitener and used in paint.

I'm sure that what gives the game away with regard to this material being red paint or potentially an anti-corrosion coating is the fact it's clearly dual layer. Could even be a primer with paint.

Themite is just a mix of fine iron oxide and aluminium powder (and sometimes Sulphur, Potassium Permanganate, Barium Nitrate). It won't form a dual layer because you require the mixture to be as well mixed as possible for it to work, it's effectively homogeneous.

It's late for me now, but I'll go over that paper a bit more closely to actually see what their claims are. You never know they could be right.
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