MURI: Nano-Engineered Energetic Materials
Transcript of MURI: Nano-Engineered Energetic Materials
MURI: Nano-Engineered Energetic Materials
• Ralph G. Nuzzo – Gregory S. Girolami– Anatoly I. Frenkel– Ray Twesten
The Frederick Seitz Materials Research Laboratory And School of Chemical Sciences
University of Illinois at Urbana-Champaign
MURI Interaction Chart
Dynamics GroupUIUC/PSU
Engineering GroupPSU
Materials GroupPSU
CharacterizationFS-MRL/CMM/UIUC
Significant Research Expertise: Al Synthesis, Fabrication, and Surface Chemistry
• SAMs on Al– “Spontaneously Organized Molecular Assemblies; I. Formation, Dynamics
and Physical Properties of n-Alkanoic Acids Adsorbed from Solution on an Oxidized Aluminum Surface,” Allara, D. L.; Nuzzo, R. G. Langmuir 1985,1, 45-52; “Spontaneously Organized Molecular Assemblies; II. Quantitative Infrared Spectroscopic Determination of Equilibrium Structures of Solution Adsorbed n-Alkanoic Acids on an Oxidized Aluminum Surface,” Allara, D. L.; Nuzzo, R. G. Langmuir 1985, 1, 52-66“Self-Assembled Monolayers of Long-Chain Hydroxamic Acids on the Native Oxide of Metals,” Folkers, J. P.; Bucholz, S.; Laibinis, P. E.; Gorman, C. B.; Whitesides, G. M., Nuzzo, R. G. Langmuir 1995, 11, 813-824.
• Al CVD Processes– “Metal-Organic Low Pressure Chemical Vapor Deposition of Aluminum,”
Green, M. L.; Levy, R. A.; Nuzzo, R. G. Thin Solid Films 1984, 114, 367-377; “Surface Organometallic Chemistry in the Chemical Vapor Deposition of Aluminum Films Using Triisobutylaluminum: b-Hydride and b-AIkylElimination Reactions of Surface Alkyl Intermediates,” Bent, B. E.; Nuzzo, R. G., Dubois, L. H. J Am. Chem. Soc. 1989, 111, 1634-1644; “The Adsorption and Thermal Decomposition of Trimethylamine Alane on Aluminum and Silicon Single Crystal Surfaces: Kinetic and Mechanistic Studies,” Kao, C.-T.; Dubois, L. H.; Zegarski, B. R.; Nuzzo, R. G. Surf. Sci. 1990, 236, 77-84; “Aluminum Thin Film Growth by the Thermal Decomposition of TriethylamineAlane,” Dubois, L. H.; Zegarski, B. R.; Gross, M. E.; Nuzzo, R. G. Surf. Sci. 1991, 244, 89-95.
• Al Surface Chemistry– 2 Patents and 10 additional Publications
Energetic Materials: Model Systems
• Model Clusters from Molecular Precursors
• Composites from Aerosol and Particle Spray Deposition Processes
• Shock Physics Targets• New Energetic Materials• Surface Chemistry• Materials Characterization
High-Energy Aluminum Nanoparticles• High surface area aluminum nanoparticles
would be ideal high-energy materials • A few examples of small aluminum clusters
have recently been described (reductive syntheses), but there are no investigations of their use as high energy materials
• The Al nanoparticles consist of metallic aluminum cores surrounded by a monolayer of a protective shell
• 10 and 100 aluminum atoms and particle diameters between 0.5 and 1.3 nm
Generalize and Expand Synthetic Approaches
Size Effects in Size Effects in Nanoscale MaterialsNanoscale Materials
Specificeffects
Smoothsizeeffects
Bulk valueχ(∞)
n-β
n‘Small’‘Large’∞
χ(n)
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Adapted from: Jena, P; Khanna, S.N.; Rao, B.K. Physics and Chemistryof Finite Systems: From Clusters to Crystals (NATO-ASI Series). 1992(Deventer: Kluwer).
Woltersdorf, J.; Nepijko, A.S.; Pippel, E. Surf. Sci. 1968, 12, 134.
Ionization Potential as a function of particle size.
The Need: Full Characterization/Understanding of Structure and Properties at all Length Scales
Nanoscale Energetic Materials: Structural
Characterization
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k (Å-1)
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High-Resolution TEM: <1 nmHigh-Resolution TEM: <1 nm
0.68Å0.68Å
Al(i-Bu)2Cl + K → K2Al12(i-Bu)12
W. Hiller, K. W. Klinkhammer, W. Uhl, J. Wagner H. Angew. Chem. Int. Ed. Engl. 1991, 30, 179.
AlCl·Et2O + LiN(SiMe3)2 → Al69[N(SiMe3)2]133-
H. Köhnlein, A. Purath, C. Klemp, E. Baum, I. Krossing, G. Stösser, and H. Schnöckel Inorg. Chem., 2001, 40 , 4830.
AlI + LiN(SiMe3)2 →Al77[N(SiMe3)2]202-
Aluminum cluster (far right) consists of nested shells containing (from left to right) 13, 44, and 20 aluminum atoms
A. Ecker, E. Weckert, and H. Schnöckel Nature 1997, 387, 379.
Generalize to Aluminum Clusters with Sizes Ranging to 100 nm
• New SAMs for Cluster Passivation and Size Control•Thermal Cluster Growth
• Ligand-Directed Association• Directed Synthesis
Nitrogen Adsorptionm2/g5–10Specific Surface Area
Laser Microtracµm10% <0.3Avg. 1.2
Particle Size Distribution (Volume Basis)
ASTM D4894°C°F
325 ±5617
Melting Peak Temperature
ASTM D4894g/L300Average Bulk Density
Test MethodUnitsValueProperty
Typical Property Data for Zonyl® MP 1100
Dispersible to ~0.2 µm Particles
Nanoparticle Metal/Fluorocarbon Composites
PFK/PFE
Thermal Spray Deposition
(e.g. TMAA / TiCl4 / MP 1100)
Nanoscale Metal/Fluorocarbon Composites II
Controlled Pore Sizes Ranging from 100 to 50 nm
Infuse with Activator
CVD Growth
CVD Growth
Soft Lithography-based Patterning Of Si/Thin Film Materials
200µm
200µm
200µm
200µm
• Large Area, 100 nM Feature Sizes Demonstrated• Polymer and Inorganic Substrates• Varied Forms and Pitches Tolerated
• Large Area Patterning• Lift-off/Wet Etch/RIE Patterning• Decal Transfer is Activated: Registration
“Solid Inks”: High Performance Thin Film Transistors as Printable Devices
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I DS(
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VGS(V)
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-3V/-5V-1V
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S D
Rogers et al. (APL)
Top View Micrograph
PI
Shock Physics Targets• New SAMs for PassivatingPlanar Al Surfaces
– Siloxane Ladders– Silamides– Oligoalkyls
• Planar Multilayer Stacks– Metal/Oxidizer/Metal…
• Lithographic Targets for Shock Experiments
– Decal Multilayer StacksPrinting “Solid Inks”
40 µm
2 µm
•Solid Organic Oxidizers• Metal Microstructures
A Large Area Printed Organic Thin Film (NAO) on Al/Si