Presentation is loading. Please wait.

Presentation is loading. Please wait.

Like SHS, is loose powder ignition a key process within mechanochemical reactions (ball milling), or is it just an anomaly for Cu 2 O? J. Zeck, Dr. Takacs,

Similar presentations


Presentation on theme: "Like SHS, is loose powder ignition a key process within mechanochemical reactions (ball milling), or is it just an anomaly for Cu 2 O? J. Zeck, Dr. Takacs,"— Presentation transcript:

1 Like SHS, is loose powder ignition a key process within mechanochemical reactions (ball milling), or is it just an anomaly for Cu 2 O? J. Zeck, Dr. Takacs, and Dr. Bakhshai Goucher College Baltimore, MD

2 Stainless Steel Milling Vials What exactly is ball milling? SPEX 8000 Mixer Mill 3CuO + 2Al  Al 2 O 3 + 3Cu 2CuO + Ti  TiO 2 + 2Cu example reactions:

3 Ignition time (seconds) Vial temperature (Celsius) Trends in Temperature When Ignition Occurs in Individual Samples

4 Ignition Trends from Summer 2001 Work

5 New material systems that have been investigated: Bi 2 O 3 + 2Al  Al 2 O 3 + 3Bi 3Ag 2 O + 2Al  Al 2 O 3 + 6Ag 3CuS+ 2Al  Al 2 S 3 + 3Cu 3Cu 2 S + 2V  V 2 S 3 + 6Cu 3CuS + 2V  V 2 S 3 + 3Cu 3ZnO + 2Al  Al 2 O 3 + 3Zn Ignition No ignition 3CuO + 2Al  Al 2 O 3 + 3Cu 2CuO + Ti  TiO 2 + 2Cu 3PbO + 2Al --> Al 2 O 3 +3Pb

6 Cu Oxide Ignition Trends; as previously looked at Comparison of CuO System’s Ignition Times as mixed with Aluminum and Titanium Powders

7 6CuO + 2Al  3Cu 2 O + Al 2 O 3 3Cu 2 O + 2Al  Al 2 O 3 + 6Cu 3CuO + 2Al  Al 2 O 3 + 3Cu Instead of single step: A two step reaction: may contribute to additional transitory region ΔH= 287.7 kcal/mol ΔH= 304.8 ΔH= 270.6

8 3CuO + 2Al  Al 2 O 3 + 3Cu

9 Is it just the copper that is causing the transitory regions? a look into bismuth... Bi 2 O 3 + 2Al  Al 2 O 3 + 3Bi

10 Would the ignition affects of ductile silver compare with copper? 3Ag 2 O + 2Al  Al 2 O 3 + 6Ag

11 How do the ignition times of lead oxide compare? 3PbO + 2Al --> Al 2 O 3 +3Pb

12 Is the anomaly just unique to the copper oxides or does it apply more generally to other copper compounds as well? 3CuS+ 2Al  Al 2 S 3 + 3Cu

13 Examples of Relative Linearity of Temperature Changes due to Ignition in various systems

14 Atomic Force Microscopy Investigation: CuO/Al 2 Gram Powder Sample—Layer Study

15 Atomic Force Microscopy Investigation: CuO/Al 5 Gram Powder Sample—Layer Study

16 Conclusions … Alternate process to established SHS Isolated case–exhibited only in Copper Oxides Cu2O– critical mass transition only CuO– critical mass and exponential decay transitions


Download ppt "Like SHS, is loose powder ignition a key process within mechanochemical reactions (ball milling), or is it just an anomaly for Cu 2 O? J. Zeck, Dr. Takacs,"

Similar presentations


Ads by Google