Letter regarding red/gray chip analyses
The following letter (with minor edits) has been sent to a scientist who recently contacted me regarding his intention to perform a study of the WTC dust, particularly the red/gray chips that we found in WTC dust samples. Included are some comments on a report by James R. Millette on red material which he found in WTC dust, sent to me by this scientist as a PDF file.
Dear [Interested Scientist],
Yes, I would encourage you to do a follow-up study on the World Trade Center dust, after you have carefully read our “Active Thermitic Materials...” paper. [Niels Harrit, Jeffrey Farrer, Steven Jones, et al. "Active Thermitic Material Discovered in Dust from the 9/11 World Trade Center Catastrophe", THE OPEN CHEMICAL PHYSICS JOURNAL, April 2009.]
Among the most salient observations in that paper are these:
1. the observation of elemental-iron-rich spheres in the ash following ignition of the red/gray chips in the Differential Scanning Calorimeter (DSC),
2. the sharp peaking of the heat-traces in each case for the ignition of red/gray chips in the DSC (Figure 19).
Therefore, I am pleased that you propose to do DSC analyses along the lines that we preformed; as you noted, James Millette did NOT do DSC analyses at all for his report MVA9119. What a shame, really, and I hope you will do better as you propose.
The presence of reduced iron (less oxygen than needed for even FeO) in these spheres (see our Figures 20 and 21) implies that a transfer of oxygen has taken place, from iron oxide to aluminum. High temperatures are also needed for the formation of iron-rich spheres (spheres formed from liquid due to surface tension), further indicating a highly exothermic thermitic reaction.
When Dr Farrer burned epoxy paint in the DSC, it gave a very broad thermal trace, NOT at all like the spiked exothermic DSC peak in our Fig 19. This is one of the many tests he did to check things.
Also, we checked the electrical resistivity of several paints – consistently orders of magnitude higher than that of the red material. We reported the resistivity of the red material in our paper, page 27 in the Journal. Millette did not report any electrical resistivity measurements. This measurement is rather easy to do so I was surprised when he failed to do this straightforward test. There is a lot of red material of various types in the WTC dust, so one must be careful to make sure it is the same as what we studied, and not some other material.
You suggest that you would like to ignite the red material in an inert atmosphere, which is not a bad idea but there are caveats. Dr Farrer of our team contacted one of the LLNL scientists about this issue, and was informed that the LLNL tests of nano-thermite were performed in air; which is why we did our tests in air also. Thus, we could make direct comparisons with the LLNL data on nano-thermite fabricated at the LLNL laboratory.
Later, we mixed up some ultra-fine aluminum and iron-oxide powders thus making a type of nano-thermite (but with no organic matrix). This was run in the DSC at BYU in an inert atmosphere up to 700C – and it did not ignite! We concluded that oxygen may be important to get the reaction initiated.
You say that the exothermic peaks we observed in the DSC (our Figure 19) could be due to burning of epoxy paint. Not according to our experiments -- that is, when Dr Farrer burned epoxy paint in the DSC, it gave a very broad thermal trace, NOT at all like the spiked exothermic DSC peaks in Fig 19. Igniting paint in the same DSC is one of many tests performed to double-check our experiments, and I urge you to do similar tests.
Please keep these facts in mind as you undertake DSC studies – which I welcome! Yes, I was surprised that James Millette did not even perform DSC studies.
Another key observation that we made:
3. Migration of aluminum in the red material as it was soaked for hours in MEK solvent, evident from Figure 15 in our paper.
If you compare frames c) aluminum and e) silicon in Fig. 15, you will see regions where the aluminum is clearly separated from the silicon. This argues against the red material being kaolinite as you and Millette suggest.
We performed experiments soaking epoxy paint chips in MEK as well. As we reported in our paper, the red material swells but remains hard under forceps after soaking for many hours. OTOH, the epoxy paint became very flimsy after soaking in the MEK for a similar length of time. This is yet another test which distinguishes the red/gray chips from paint!
Dr Farrer and I did some work with Transmission Electron Microscopy after the paper was published, looking at aluminum-containing platelets which we were able to isolate quite well in the thin sample. We found that the Al and Si are in fact NOT in equal amounts; the Al:Si ratio came out to approximately 0.92 (based on atomic wt %, TEM focused on a platelet.) How could this be the mineral kaolinite as you suggest, for which the Al:Si ratio is exactly 1.0? Formula: Al2Si2O5(OH)4 .
The accuracy of the TEM analysis should allow you (and Millette) to determine if you are indeed looking at the same material that we reported on, beginning with the Al:Si ratio.
I encourage you to do TEM analysis as we have done. Studying electron-diffraction patterns obtained with the TEM, Dr. Farrer found that that the iron-oxide was in the form Fe2O3. He did not see a pattern demonstrating that aluminum was in a form he recognized by this method, which surprised us. There are possible explanations for this; see for example http://www.tms.org/pubs/journals/jom/0203/perepezko-0203.html . I'll leave it at that for now. I have encouraged Dr. Farrer to write up and publish his TEM findings. Did Millette see an electron diffraction pattern demonstrating that aluminum occurs in the form of kaolinite? His report does state:
Millette report: "TEM-SAED-EDS analysis of a thin section of the red layer showed equant-shaped particles of iron consistent with iron oxide pigments and plates of kaolin clay (Figures 20 and 21). The matrix material of the red coating layer was carbon-based. Small numbers of titanium oxide particles consistent with titanium dioxide pigment and some calcium particles were also found (Appendix F).”
We did TEM analysis also, years ago now, but we did not see any titanium in the red/gray chips! (Referring specifically to the clean-surface chips; see Figs. 6 and 7 in our published paper.) More and more, it appears that Millette was simply not looking at the same material that we studied.
Why would he not measure the electrical resistivity of his red material (discussed in our paper) right off? That's what gets me – he could have saved himself a lot of time. Finally he gets to TEM analysis, and finds that he has titanium oxide! How can he claim its the same material? What a waste of time. I hope you will not make the same mistake.
Steven E. Jones
Note added, based on comments received 9-9-12 from Dr. Jeffrey Farrer.
1. Dr. Farrer contacted Dr. Tillotson of LLNL regarding the LLNL production and ignition of nano-thermite; Dr Tillotson said the experiments were likely done in atmosphere. After publication of our paper, others have suggested that the experiments in the LLNL publication were performed in an inert atmosphere; so the picture is not clear to us at this time and further contact with the LLNL scientists is advised. It would be best to run studies in both atmosphere and in an inert gas.
2. The DSC run with the ultra-fine aluminum and iron-oxide (which did not ignite in atmosphere) may have been heated to approximately 800 degrees centigrade. Jeff will check his notes.
3. It would be desirable for the interested scientist to do more tests in the DSC of the type we did with epoxy paint. We have a sample of actual primer paint used on the World Trade Center, available for testing. The XEDS analysis shows that this WTC-paint has a chemical signature which dramatically differs from that of the red material we reported on (Figure 7 in our paper).
4. The interested scientist is encouraged to do the MEK-soak test along with SEM analyses.
5. With regard to the 0.92 ratio, Jeff notes that he did not use standards for the TEM/XEDS analysis so this ratio could be consistent with unity. The interested scientist is encouraged to use standards for the TEM/XEDS so this ratio can be pinned down definitively.
6. Jeff notes that in his TEM analyses he observed “very small (nanometer-scale) Pb particles in the TEM samples” as well as strontium and chromium in small amounts. (Much of the TEM analysis was performed at higher magnification than used in the SEM analysis done in the paper.) Thus, red/gray chips which match ours will show these same elements under TEM analysis.
I (Dr. Jones) have searched Millette's plots and see no indication of strontium (Sr) or lead (Pb) in his samples, but he does report titanium (Ti) which we do not see. Thus, his samples do not appear to be the same material as what we reported on.