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FORMATION OF ALUMINUM NANOPOWDERS AND THEIR APPLICATION IN NANOENERGETIC MATERIALS

FORMATION OF ALUMINUM NANOPOWDERS AND THEIR APPLICATION IN NANOENERGETIC MATERIALS. Dr. Jan A. Puszynski Chemistry and Chemical Engineering Department South Dakota School of Mines & Technology Rapid City, SD 57701 Tel: 605/394-5268 Fax: 605/394-5266 E-mail: Jan.Puszynski@sdsmt.edu. 1.5 nm.

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FORMATION OF ALUMINUM NANOPOWDERS AND THEIR APPLICATION IN NANOENERGETIC MATERIALS

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  1. FORMATION OF ALUMINUM NANOPOWDERS AND THEIR APPLICATION IN NANOENERGETIC MATERIALS Dr. Jan A. Puszynski Chemistry and Chemical Engineering Department South Dakota School of Mines & Technology Rapid City, SD 57701 Tel: 605/394-5268 Fax: 605/394-5266 E-mail: Jan.Puszynski@sdsmt.edu

  2. 1.5 nm 100 nm PARAMETRIC STUDIES: FORMATION OF ALUMINUM NANOPOWDERS

  3. Mathematical Modeling of Aerosol Dynamics

  4. Stages in Particle Formation

  5. Modeling the Aerosol Dynamics • The rate of change of various moments of the aerosol size distribution for the nth cell can be written by : First Moment, M1 Aerosol Surface Area, A Aerosol Number Density, N

  6. Modeling the Aerosol Dynamics • d1 , s1 , v1 are the monomer diameter, surface area and volume respectively. • The saturation ratio S is given by: • The nucleation rate I is given by:

  7. Schematic Representation of Cascade Flow Model

  8. Modeling the Aerosol Dynamics In the case of several CSTAGs (Continuous Stirred Tank Aerosol Generator) in series, the governing mass balance equation is given by:

  9. 2-D Temperature Profiles in the Al Nano-Powder Generator (PHe=5Tr)

  10. 2-D Temperature Profiles in the Al Nano-Powder Generator (PAr=5Tr)

  11. Axial Temperature Profiles in the Generator for Helium and Argon

  12. Median Particle Diameter vs. Inert Gas Pressure

  13. Characterization of uncoated and coated aluminum nanopowders. • DETERMINATION OF REACTIVE ALUMINUM CONTENT • Thermogravimetric method (TGA) • Volumetric method (VM) • Bomb calorimetry method (BCM)

  14. TGA of Aluminum Nanopowders 20.22 wt % of reactive aluminum 67.78 wt % of reactive aluminum

  15. Comparison of TGA, Volumetric, and Bomb Calorimetry Methods

  16. Surface Functionalization of Al Nanopowders And Their Reactivity with Moisture and Liquid Water • Mixing • Processing • Long-term stability

  17. Effect of Moisture on Aluminum Nanopowders

  18. Effect of Moisture (97% RH) on Coated and Uncoated Aluminum Nanopowders

  19. Ageing of Aluminum Nanopowders in Liquid Water

  20. Aged 0 hrs, 74 wt% reactive Al Aged 40 hrs, 59 wt% reactive Al Ageing of Aluminum Nanopowders 97% RH and 40oC

  21. Aged 80 hrs (97% RH), 0 wt% reactive Al Aged 60 hrs (97% RH), 17 wt% reactive Al Ageing of Aluminum Nanopowders

  22. Aluminum Nanopowder Coated with 4 wt% of Silane

  23. DISPERSION AND MIXING OF NANO-POWDERS

  24. Sedimentation of AluminumNano-powder in Hexane J Time: 30 sec Time: 50 sec Time: 5 min Time: 30 min Without dispersant With dispersant (2 wt% sodium dioctyl sulfosuccinate, SDS)

  25. Characterization of Mixing Quality of Binary Nano-powders (high resolution) Wet Mixing of Al(red) / TiO2(blue) System (with SDS dispersant): SE/Cameo Image 50,000X SE/BSE/Element Mapping 50,000X SE/Element Line Scan 50,000X

  26. Al-TiO2-mixture prepared in absolute ethanol with sodium dioctyl sulfosuccinate as surfactant. Sample after three line scans of 10 mm at 10000 X.

  27. Mixing Index for the Mixtures of Nanosized Powders Mixing Index AK,L for different samples 0.945 0.950 0.955 0.536 Wet mixing hexane Wet mixing ethanol(w/disp.) Wet mixing hexane (w /disp.) Dry mixing

  28. INVESTIGATION OF COMBUSTION CHARACTERISTICS IN SYSTEMS CONTAINING ALUMINUM AND METAL OXIDES NANOPOWDERS

  29. Adiabatic Temperature of Energetic Reacting Systems

  30. Schematics of the Burn Test Equipment

  31. t= 0.1 t= 100 t= 200 t= 300 t= 500 t= 600 t= 800 Reacting System: Nanosize Al (40 nm) and Nanosize Fe2O3 (Nanophase Technologies, Corp.) • Combustion Front Velocity: 30 m/s • Recording Speed: 8000 frames/sec • Playback Rate: 30 frames/sec

  32. t= 0.1 t= 50 t= 100 t= 150 t= 160 t= 170 t= 200 Reacting System: Nanosize Al (50 nm NSWC/IH)and Micronsize MoO3 (Climax Molybdenum Company) With Perforated Baffles

  33. Effect of Coating on Combustion Front Velocity Under Unconfined Conditions

  34. Effect of Coating on Ignition Delay Time Wt% of Coating Wt% of Coating Wt% of Coating

  35. Effect of Average Particle Size of Aluminum on Burn Rate in Al-CuO System

  36. Schematics of the pressure vessel equipment

  37. LEADS FROM THERMOCOUPLE TO DATA AQUISITION MOLYBDENUM IGNITION WIRE Aluminum loose powder Equipment for Burn test of Aluminum Pressure Vessel Experimental Set-up under confined conditions Alumin Boat Reactor Reactor AUTO TRANSFORMER FLANGE 2 FLANGE 1 REACTOR GAS INLET CAMERA PRESSURE GAUGE SAFETY VENT VALVE THERMOCOUPLE WIRES DATA ACQUISITION SYSTEM VACUUM PUMP

  38. Pmax IDT Pressure Responses in Al (uncoated)-CuO System

  39. Effect of Coating on Ignition Delay Time Wt% of Coating Wt% of Coating Wt% of Coating

  40. New experimental technique: Recoil force measurement during unconfined burn of a nanoenergetic mixture. Linear range: 0 – 1000 N Sensitivity : ~200 mV/1000 N Load cell (force transducer) : Entran Devices, Inc.

  41. Average recoil force during combustion of the MICs

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