Scalable Manufacturing of Energetic Materials

for Integrated Systems

Stephen Tse, Alberto Cuitino, Fernando Muzzio,

Assimina Pelegri, and Bernard Kear

School of Engineering, Rutgers University

Piscataway, NJ 08854

Inaugural Meeting of the National Energetic Materials Consortium

Texas Tech University

13 October 2015

Outline

Nanowire Synthesis of NanoEnergetics

Nanoparticle Synthesis of Cubic Boron Nitride

In-situ Laser-Based Diagnostics

Graphene Synthesis

Characterization and Continuous Automation of an Environmentally Green Primer

Nanowire Synthesis

Relevance -- Nanowires

Robust materials with improved properties are needed for structural, functional, and device applications

Of strong interest are functional one-dimensional nanostructures due to their unique and innovative applications in optics, optoelectronics, catalysis, and piezoelectricity

Semiconducting oxide nanowires constitute a unique group of 1D nanomaterials, which have well-defined and uniform shapes, stable surfaces, and single-crystal volumes

These properties are keys to nanoelectronic applications like use as field effect transistors, ultra-sensitive nano-size gas sensors, nanoresonators, and nanocantilevers

Relevance -- Nanowires

Moreover, nanowires of MoO3, CuO, WO3, Fe2O3, Bi2O3, and MnO2 can be exploited for tailored heat release in nano-energetic applications involving thermite reactions with nano-Al

substrate

metal-oxide

nanowire

Al coatingAl nanoparticle

metal-oxide

nanowire

substrate

Motivation

Many approaches have been used to prepare nano-wires/rods, such as vapor-liquid-solid growth, solution-liquid-solid methods, template mediate growth, electron beam lithography, and scanning tunneling microscopy techniques

However, these methods can be complex, involving pretreatment, catalysts, and vacuum systems, while still characterized by low single-nanowire growth rates and low total yield densities

Consequently, studies on nanoscale materials and their applications are presently limited due to lack of easy processes for high- rate, yield, purity, and orientation synthesis of such materials

The growth of metal-oxide nanowires over large areas remains especially challenging

Quasi 1-D Flame

Counterflow Diffusion Flame

Spontaneous Raman Spectroscopy

2x Nd:YAG LaserPulse-StretcherM

M

BSPower

Meter

Image Rotator

ICCD Camera

Prism

Imaging

Spectrometer

L

L

Raman Notch Filter

Achromats

Beam

Dump

Retroreflector

x

y

z3-D translation

CVD Chamber with optical access

Delay/Gate

GeneratorComputer

beam

Axi-symmetric counterflow diffusion flame

code

GRI-Mech 1.2 (32 species, 177 reactions)

Transport properties computed with

CHEMKIN subroutines

Boundary conditions at burners specify plug

flow inlet mass flux and temperature

Gas-Phase Simulation

Temperature & major species With correction from interference

from C-containing radicals

0.00%

10.00%

20.00%

30.00%

40.00%

50.00%

60.00%

-0.6 -0.3 0 0.3 0.6 0.9position/mm

0

500

1000

1500

2000

2500O2

CH4

H20

H2

Sum/4

T

0.00%

2.00%

4.00%

6.00%

8.00%

10.00%

12.00%

-0.6 -0.3 0 0.3 0.6 0.9position/mm

CO2

CO

C2H2

Flame Structure Validation (Raman)

15m

m

Air nozzle

CH4 + N2

Fuel nozzle

Substrate prober

z

Experiment and Flame Structure

Dense yield of nanomaterials grown directly on a tungsten substrate

Diameters of 20-50nm, lengths > 10µm, 10min sampling duration

EDX tungsten oxide

Aligned Tungsten-Oxide Nanowires

20 nm

Different crystal structures

include: cubic and monoclinic

WO3, tetragonal WO2.9, and

monoclinic W18O49

Indexed SAED pattern with the

first three highest intensities of

3.779Å, 3.126Å, and 2.67Å

match very well with the

tetragonal phase of WO2.9 with

lattice constants of a = 5.3Å, b

= 5.3Å, and c = 3.83Å (PDF

card #18-1417)

d-spacings correspond to {110},

{101}, and {200}, respectively

TEM of Tungsten Oxide (WO2.9)

10 nm

0.378 nm

[110]

Dislocation-free, single-crystalline

2-D Fourier transform pattern gives

average spacing for lattice planes of

3.78Å, which corresponds to the

reflections from d-spacings of (110)

planes of the tetragonal WO2.9 phase

Preferable growth along the [110]

direction

Crystallinity

Growth appears to be by vapor-solid (VS)

mechanism– no metal nanoparticle at its tip (VLS)

– thickening by a ledge-growth mechanism

20 nm

Growth Mechanism

Zinc Oxide

Molybdenum Oxide

Molybdenum oxide grown in the CH4

flame on the air side (z=+.83cm) at

low magnification (top) and high

magnification (bottom)

Molybdenum oxide grown in the H2

flame on the fuel side at 5,000X (top)

and 10,000X (bottom)

Fuel Side (2000K)Air Side (2000K)

Copper Oxide

Low magnification copper oxide

nanowires grown in a CH4 flame

(z=+0.97cm) (top)

Magnified FESEM image of

nanowires grown in CH4 (bottom)

Low magnification showing yield of

copper oxide from H2 flame

(z=+0.97cm) (top)

Typical image of copper oxide grown

in the H2 flame (bottom)

Air Side (900K)

Iron Oxide

Low magnification iron oxide

nanowires grown in a CH4 flame (top)

Magnified FESEM image of

nanowires grown in CH4 (bottom)

Low magnification showing dense

yield of iron oxide from H2 flame (top)

Typical image of iron oxide grown in

the H2 flame(bottom)

Air Side (1000K)

Energetics

Nanoscale energetic materials have the potential for

enhanced energy release and mechanical properties, versus

their conventional counterparts

Energetic nanomixtures and nanocomposites e.g. Thermite

reactions (Al/MoO3, Al/CuO, Al/WO3, Al/Fe2O3, Al/Bi2O3, and

Al/MnO2)

– Based on intermolecular, rather than intramolecular, reactions,

energetic nanocomposites require intimate mixing of the

reactants on the nanometer length scale

– The use of nanoscale structures enhance chemical kinetics due

to their high surface area and short diffusion length

– Given the proximity and uniformity of the fuel and oxidizer

nanostructures, the final nanophase composite can be extremely

dense in energy and capable of generating high power

Densities and Reaction Enthalpies

From Ed Dreizin

0

20

40

60

80

100

120

He

at R

ele

ase

H

[kJ/c

m3]

Al-

MoO

3

Al-

CuO

Al-

WO

3

Al-

Fe2O

3

Al-

Bi2

O3

Al-

MnO

2

Al-

Ni

B-T

i

B-Z

r

Al-

Teflon

Full OxidationThermite/Intermetallic Reaction

0

1

2

3

4

5

6

7

8

Th

eo

retica

l M

axim

um

D

en

sity [g

/cm

3]

• Wide range of

material densities is

readily available (Al-Teflon composite

shown for comparison)

• Reaction enthalpies

are very high

• Oxidation of the

reaction products by

ambient air adds

significant

combustion energy

Relevance -- Nanowires

Moreover, nanowires of MoO3, CuO, WO3, Fe2O3, Bi2O3, and MnO2 can be exploited for tailored heat release in nano-energetic applications involving thermite reactions with nano-Al

substrate

metal-oxide

nanowire

Al coatingAl nanoparticle

metal-oxide

nanowire

substrate

Nanoenergetic Materials for MEMS

Zhang et al., Applied Physics Letters, 2007

– Grew CuOx nanowires by thermal oxidation of electroplated Cu

layer

Nanoenergetic Materials for MEMS

Menon et al., Applied Physics Letters, 2004

– embedded an array of Fe2O3 nanowires inside a thin Al film

(1) Electrochemical anodization of Al foil to form nanoporous

alumina templates

(2) Fe nanowire fabricated inside nanopores by electrochemical

deposition

(3) Etching of alumina walls to reveal Fe nanowires

(4) Fe nanowires oxidized into Fe2O3 nanowires by annealing

Experiment Set-up

W

Burner

Burner

Al coatingWO2.9 NW

Step 2

Bath

Al

Step 1 Step 2

Electrodeposition Procedure

• Tungsten oxide nanowires array fabricated by flame synthesis

method.

• Al layer with thickness of ~16nm directly deposited on the

surface of WO2.9 nanowires by the ionic-liquid

electrodeposition method under an inert atmosphere.

• A 1.5:1 molar ratio of aluminum chloride and 1-ethyl-3-

methylimidazolium chloride ionic liquids were employed as the

electrolyte at room temperature.

• The working electrodes were a tungsten wire with WO2.9

nanowires grown on its surface and an aluminum wire. A

potential of -1.5 V DC was applied for 15 minutes to fabricate

the desired coaxial WO2.9/Al nanowires.

Jiang, T.; Chollier Brym, M. J.; Dubé, G.; Lasia, A.; Brisard, G. M.

Surf. Coatings Technol. 2006, 201, 1–9.

Morphology

(a) (b)

(a) Low magnification FESEM image of as-synthesized tungsten oxide

nanowires array by flame synthesis method and side-view image of the array

showing well-aligned vertical growth (insert).

(b) Low magnification FESEM image of as-grown WO2.9/Al coaxial nanowires

after electrodeposition and high magnification FESEM image of the coaxial

nanowires (insert).

Morphology and Elemental Composition

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

Inte

nsi

ty (

a.u

.)

Energy (keV)

CO

Al

W

W

W Cl Cl

10 nm5 1/nm

[110]

WO2.9

20 nm

WO2.9

Al

(e)

HRTEM Structure Characterization

• Atomically abrupt interface

• Transition monolayer

Combustion Reaction

Al-Coated MoO2 Nanoplates

MoO2 thickness ~74 nm

MoO2 /Al thickness ~200 nm

Al layer thickness ~63 nm

45 min deposition time other than 15 min for

WO2.9/Al system to verify the time effect

MoO2 MoO2/Al

Nanoparticle Synthesis of Cubic Boron Nitride

Potential Defense Application(s):• Nano-ceramic composites provide superior hardness, stiffness,

bend strength, tensile strength and fracture toughness. • Robust materials of high strength and enhanced toughness are

needed for many applications, including heavy and light

(including transparent) armor, gun-barrels and liners, machine

tools, lubrication-free bearings, and optoelectronic devices in

harsh environments.

Nanocrystalline Cubic Boron Nitride

Scientific/Technical Approach Summary:

Program Approach:

Pathway to Goal:

• Plasma synthesis and consolidation will be used to produce ~1-2cm diameter (~0.5-1cm) thick nanocrystalline c-BN samples.

New Insights/Innovations:• Synthesize and consolidate

nanopowders of the c-BN to produce

extended-solid nanomaterials with

superior hardness, stiffness, bend

strength, tensile strength, and fracture

toughness.

• Reducing the grain size of single- or

multi-phase materials to nanoscale

dimensions yields significant

improvements in mechanical properties

(> 1.5 times).

• Ability to make large monoliths by

working with end-user companies (e.g.

DI, Megadiamond) that have up to

30,000 ton presses.

Precursor

Plasma

gas

Auxiliary

gas

RF Coil

Evaporation

Dissociation

Reaction

Condensation

Nucleation

Quenching

Cold Substrate

Synthesis Parameters• RF power

• Gas (Ar, H2, N2, CH4)

• Ambient pressure & gas

• Mass flow rates

• Precursor loading

• Substrate temperature

• Substrate voltage bias

• Substrate distance

In-Situ Laser-Based

DiagnosticsGas-Phase diagnostics

• Temperature (SRS, FRS, OES. LIF)

• Chemical species (SRS, LIF, OES)

• Flow field velocity (PIV)

Particle diagnostics

• Composition (LIBS)

• Crystallinity (Raman)

• Size/Distribution (LII)

Ex-Situ Powder Characterization

• Phase & crystallinity (XRD)

• Morphologies & primary particle size (TEM)

• Aggregate particle size (DLS)

Computational Modeling

Gas-Phase phase

• Temperature

• Chemical species

• Flow field velocity

Particle growth & transport

• Sectional Model (precursor

decomposition, nucleation,

surface growth, coagulation,

coalescence)

• Aerosol dynamics

• Powder surface area (BET)

• Particle size distribution (nano-SMPS)

• Precursor conversion (TGA)

Correlation Correlation

Optimize

ProcessPredict & Guide

Experiments

ValidationPrecursor

Plasma

gas

Auxiliary

gas

RF Coil

Evaporation

Dissociation

Reaction

Condensation

Nucleation

Quenching

Cold Substrate

Synthesis Parameters• RF power

• Gas (Ar, H2, N2, CH4)

• Ambient pressure & gas

• Mass flow rates

• Precursor loading

• Substrate temperature

• Substrate voltage bias

• Substrate distance

In-Situ Laser-Based

DiagnosticsGas-Phase diagnostics

• Temperature (SRS, FRS, OES. LIF)

• Chemical species (SRS, LIF, OES)

• Flow field velocity (PIV)

Particle diagnostics

• Composition (LIBS)

• Crystallinity (Raman)

• Size/Distribution (LII)

Ex-Situ Powder Characterization

• Phase & crystallinity (XRD)

• Morphologies & primary particle size (TEM)

• Aggregate particle size (DLS)

Computational Modeling

Gas-Phase phase

• Temperature

• Chemical species

• Flow field velocity

Particle growth & transport

• Sectional Model (precursor

decomposition, nucleation,

surface growth, coagulation,

coalescence)

• Aerosol dynamics

• Powder surface area (BET)

• Particle size distribution (nano-SMPS)

• Precursor conversion (TGA)

Correlation Correlation

Optimize

ProcessPredict & Guide

Experiments

Validation

Metastable Nanopowder synthesis: plasma and flame synthesis, with in-situ laser-based diagnostics, computational modeling, and powder characterization

Consolidation: high pressure / high temperature (e.g. 5GPa / 1000°C)

4.5mm

Synthesis of < 20nm nanoparticles of metastable (high-pressure, extended solid phase) cubic boron nitride (c-BN)

95%c-BN 17nm grainbulk sample

B

C N

BN

B4+C

“C3N4”

B2CN2

BC2NBC4NBC3N

B4N

mol-%

B

mol-%

B

mol-% C

“C3N4”Cdiamond

c-BN

B4C

TiCSiC

Al2O3 TiN

Si3N4

super

hard

hard

hardness

B

C N

BN

B4+C

“C3N4”

B2CN2

BC2NBC4NBC3N

B4N

mol-%

B

mol-%

B

mol-% C

B

C N

BN

B4+C

“C3N4”

B2CN2

BC2NBC4NBC3N

B4N

mol-%

B

mol-%

B

mol-% C

“C3N4”Cdiamond

c-BN

B4C

TiCSiC

Al2O3 TiN

Si3N4

super

hard

hard

hardness

“C3N4”Cdiamond

c-BN

B4C

TiCSiC

Al2O3 TiN

Si3N4

super

hard

hard

hardness

Self nanocomposite of superhard (extended

solid - cubic) and tough (equilibrium –hex) nanograined

phases

B

C N

BN

B4+C

“C3N4”

B2CN2

BC2NBC4NBC3N

B4N

mol-%

B

mol-%

B

mol-% C

“C3N4”Cdiamond

c-BN

B4C

TiCSiC

Al2O3 TiN

Si3N4

super

hard

hard

hardness

B

C N

BN

B4+C

“C3N4”

B2CN2

BC2NBC4NBC3N

B4N

mol-%

B

mol-%

B

mol-% C

B

C N

BN

B4+C

“C3N4”

B2CN2

BC2NBC4NBC3N

B4N

mol-%

B

mol-%

B

mol-% C

“C3N4”Cdiamond

c-BN

B4C

TiCSiC

Al2O3 TiN

Si3N4

super

hard

hard

hardness

“C3N4”Cdiamond

c-BN

B4C

TiCSiC

Al2O3 TiN

Si3N4

super

hard

hard

hardness

Nanocrystalline Cubic Boron Nitride Monolith

Dimer-stabilized {100} Facets

<Cube Nanoparticle: NVE 400K>

Minimize ground state energy: dangling bonds -> dimerization

<Relaxed structure at ground state>

Similar to silicon {100} surface reconstruction

Phase Separation Driven Melting

0 ps 500 ps 1 ns

2 ns 3 ns 3.5 ns

2-fold boron corner

boron rich

core

Nitrogen rich

shell

• NVT simulation: T=3340K Corner-initiated melting

boron cluster

C-BN NPs: Mixture of {100} & {111} Facets

• Computational extensive NVT simulations: temperature is around

2900K

41

<2.04 nm: NVT 50ns >

<2.55 nm: NVT 50ns >

<3.57 nm: NVT 40ns >

Mishima O, Era K. Science and technology of boron nitride.

Electric Refractory Materials. 2000:495-556

<2.55 nm: NVT 50ns >Kagamida M, Kanda H, Akaishi M, Nukui A, Osawa T,

Yamaoka S.

Crystal growth of cubic boron nitride using Li3BN2 solvent

under high temperature and pressure. J Cryst Growth.

1989;94(1):261-269 .

Orientation Alignment and Grain Growth

100ps, T=2900K 38ns, T=3050K

0ps

• 50-ns NVE simulation with initial T=2815K

(100K~200K below melting temperature)

• Two octahedron nanoparticles align

gradually at temperature exceeds 2900K

• At 38ns, the temperature reaches 3050K

(above melting temperature)

Rapid Grain Growth at High Temperature

<100ps, T=3050K>

<8ns, T=3125K>

<12ns, T=3230K>

<15ns, T=3320K>

<16ns, T=3540K>

Initial T=3020K

(~ melting temperature)

<top view> <front view>

Competition between

grain growth

&

phase separation

In-situ Laser-Based Diagnostics

Research Paradigm

Precursor

Plasma

gas

Auxiliary

gas

RF Coil

Evaporation

Dissociation

Reaction

Condensation

Nucleation

Quenching

Cold Substrate

Synthesis Parameters• RF power

• Gas (Ar, H2, N2, CH4)

• Ambient pressure & gas

• Mass flow rates

• Precursor loading

• Substrate temperature

• Substrate voltage bias

• Substrate distance

In-Situ Characterization

Gas-Phase diagnostics

• Temperature (SRS, FRS, OES. LIF)

• Chemical species (SRS, LIF, OES)

• Flow field velocity (PIV)

Particle diagnostics

• Composition (LIBS)

• Crystallinity (Raman)

• Size/Distribution (LII)

Ex-Situ Powder Characterization• Phase & crystallinity (XRD)

• Morphologies & primary particle size (TEM)

• Aggregate particle size (DLS)

Computational Modeling

Gas-Phase phase

• Temperature

• Chemical species

• Flow field velocity

Particle growth & transport

• Sectional Model (precursor

decomposition, nucleation,

surface growth, coagulation,

coalescence)

• Aerosol dynamics

• Powder surface area (BET)

• Particle size distribution (nano-SMPS)

• Precursor conversion (TGA)

Correlation Correlation

Optimize

ProcessPredict & Guide

Experiments

ValidationPrecursor

Plasma

gas

Auxiliary

gas

RF Coil

Evaporation

Dissociation

Reaction

Condensation

Nucleation

Quenching

Cold Substrate

Synthesis Parameters• RF power

• Gas (Ar, H2, N2, CH4)

• Ambient pressure & gas

• Mass flow rates

• Precursor loading

• Substrate temperature

• Substrate voltage bias

• Substrate distance

In-Situ Characterization

Gas-Phase diagnostics

• Temperature (SRS, FRS, OES. LIF)

• Chemical species (SRS, LIF, OES)

• Flow field velocity (PIV)

Particle diagnostics

• Composition (LIBS)

• Crystallinity (Raman)

• Size/Distribution (LII)

Ex-Situ Powder Characterization• Phase & crystallinity (XRD)

• Morphologies & primary particle size (TEM)

• Aggregate particle size (DLS)

Computational Modeling

Gas-Phase phase

• Temperature

• Chemical species

• Flow field velocity

Particle growth & transport

• Sectional Model (precursor

decomposition, nucleation,

surface growth, coagulation,

coalescence)

• Aerosol dynamics

• Powder surface area (BET)

• Particle size distribution (nano-SMPS)

• Precursor conversion (TGA)

Correlation Correlation

Optimize

ProcessPredict & Guide

Experiments

Validation

In-Situ Raman of Nano-Aerosol

Technique to characterize nanoparticles during gas-phase synthesis

Validation and calibration with titania (and alumina) nanoparticles– Powder on glass slides at RT with in-situ optics layout

– Nanoparticle-seeded co-flow jet diffusion (phase evolution at high temperatures)

– Application during flame synthesis of titania

– Application during plasma synthesis of c-BN

2x Nd:YAG LaserPulse-StretcherM

M

BSPower

Meter

Image Rotator

ICCD Camera

Prism

Imaging

Spectrometer

L

L

Raman Notch Filter

Achromats

Beam

Dump

Retroreflector

x

y

z3-D translation

CVD Chamber with optical access

Delay/Gate

GeneratorComputer

beam

Spontaneous Raman

100 200 300 400 500 600 700

Raman Shift (cm-1

)

Inte

nsi

ty (

a.u.)

145 (Eg)

397 (B1g)

516 (A1g+B1g)

639 (Eg)

100 200 300 400 500 600 700

Raman Shift (cm-1

)

Inte

nsi

ty (

a.u.)

Rutile (Ref. [43])

Anatase (Ref. [43])

Anatase (Raman microscope)

146 (Eg)

398 (B1g)

516 (A1g+B1g)

639 (Eg)

197 (Eg)

Powder Characterization

In-situ Calibration with Seeded Flame

N2 w/o TiO2

N2 w/TiO2

Vibration

Air

Oxidizer

(Air)

Facility Air

Cylinder Gases

Exhaust

(Through

Liquid N2

Trap)

CH4N2

Aerosol

Feeder

Quartz cylinder

Co-flow flame

Laser beam

N2 w/o TiO2

N2 w/TiO2

Vibration

Air

Oxidizer

(Air)

Facility Air

Cylinder Gases

Exhaust

(Through

Liquid N2

Trap)

CH4N2

Aerosol

Feeder

Quartz cylinder

Co-flow flame

Laser beam

100 200 300 400 500 600 700

Raman Shift (cm-1

)

Inte

nsi

ty (

a.u

.)

g:15.0mm, 1715K, 65mW

f:12.5mm, 1554K, 65mW

e:10mm, 1533K, 60mW

d:7.5mm, 1386K, 60mW

c:5.0mm, 1253K, 60mW

b:2.5mm, 763K, 30mW

a:0.0mm,664K, 30mW

R R

R

A

AA

A

A

A

ARR

100 200 300 400 500 600 700

Raman Shift (cm-1

)

Inte

nsi

ty (

a.u

.)

g:15.0mm, 1715K, 65mW

f:12.5mm, 1554K, 65mW

e:10mm, 1533K, 60mW

d:7.5mm, 1386K, 60mW

c:5.0mm, 1253K, 60mW

b:2.5mm, 763K, 30mW

a:0.0mm,664K, 30mW

R R

R

A

AA

A

A

A

ARR

100 200 300 400 500 600 700

Raman Shift (cm-1

)

Inte

nsi

ty (

a.u

.)

g:15.0mm, 1715K, 65mW

f:12.5mm, 1554K, 65mW

e:10mm, 1533K, 60mW

d:7.5mm, 1386K, 60mW

c:5.0mm, 1253K, 60mW

b:2.5mm, 763K, 30mW

a:0.0mm,664K, 30mW

R R

R

A

AA

A

A

A

ARR

100 200 300 400 500 600 700

Raman Shift (cm-1

)

Inte

nsi

ty (

a.u

.)

g:15.0mm, 1715K, 65mW

f:12.5mm, 1554K, 65mW

e:10mm, 1533K, 60mW

d:7.5mm, 1386K, 60mW

c:5.0mm, 1253K, 60mW

b:2.5mm, 763K, 30mW

a:0.0mm,664K, 30mW

R R

R

A

AA

A

A

A

ARR

100 300 500 700

Raman shift (cm-1

)

Inte

nsi

ty (

a.u

.)

a:2.5mm, 907K

b:7.5mm, 1305K

c:12.5mm, 1420K

d:17.5mm, 1493K

e:22.5mm, 1600K

A

A AA

Flame

Cooling Water

Cooled

substrate

Flat Flame Burner

Premixed H2 + O2

&

Precursor vapor + Carrier gas

Flame

Cooling Water

Cooled

substrate

Flat Flame BurnerFlat Flame Burner

Premixed H2 + O2

&

Precursor vapor + Carrier gas

In-Situ Raman of Nanoparticles

MD of Nanoparticles

Experimental setup

55

Schematic of the stagnation swirl flame setup for TiO2 nanoparticle

synthesis and the temperature along axis (measured by N2 Raman)

0 4 8 12 16300

600

900

1200

1500

1800

2100

Tem

per

atu

re (

K)

Distance from nozzle, h (mm)

Schematic of the laser diagnostic system

Nd:YAG Laser

532nm / 355nm

ICCD

Prism

Prism

Image

Rotator

Lens

Achromats

Burner

1.5GHz Oscilloscope

Computer

Laser Beam

Beam

DumpPhotodiode

Aperture

PMT

Stage 1

Stage 2

Stage 3

TriVista

Sketch of the laser diagnostic system

Particle characterization

57

20 30 40 50 60 70 800

1000

2000

3000

4000

5000

Inte

nsi

ty (

counts

)

2(deg)

XRD anatase (with database marked as red lines)

TEM particle size 6-8 nm (2mm above substrate and on substrate)

XRD and TEM of particles

Typical LIBS signal from Ti atomic emission

58

496 498 500 502 504 5060

5000

10000

15000

20000

25000

30000

Inte

nsity (

a.u

.)

Wavelength (nm)

516 518 520 522 524 5260

3000

6000

9000

Inte

nsity (

a.u

.)Wavelength (nm)

Emission spectra acquired from a laser excitation of 532nm (35mJ/pulse, 28J/cm2),

Ti atomic spectra from NIST database marked by red lines.

Signal detected from particles on substrate not excited by flame

Al signal detected from Al2O3 particles broad applicability

Low laser energy (28J/cm2), no visible plasma

Existence of free electron plasma-proof

Peak fitting of Ti atomic emission with a laser fluence of 28J/cm2

line broadening Stark broadening

Gas breakdown Calibration of Stark broadening

parameter via comparing the broadening parameter of Ti

and N Stark broadening parameter

Electron

density

3×1017

cm-3

498 500 742 744 746 7480

2000

4000

6000

8000

10000

1200096 J/cm

2, gas breakdown, 900ns delay

Inte

nsity (

a.u

.)Wavelength (nm)

Ti atomic lines

N atomic lines

498 500 740 742 744 746

0

5000

10000

15000

20000

25000

30000

28J/cm2, no gas breakdown, no delay

Inte

nsity (

a.u

.)

Wavelength (nm)

Ti lines

N lines

LIBS for measurement of particle volume fraction

61

The increase of signal intensity versus particle

volume fraction (controlled by the loading rate of precursor)

2D measurement

62Two-dimensional distribution of particle-phase Ti imaged with a

500 nm band pass filter (FWMH 10 nm), laser fluence 24J/cm2

Low-intensity LIBS with subsequent resonant excitation

New emission line at 497.534nm

Much stronger than other emissions – better detection threshold

Comparison of the emission spectra from a) 532nm and b) 355nm laser excitation

496 497 498 499 500 501 502 5030

3000

6000

9000

12000

50

1.4

28

nm

50

0.7

20

nm

49

9.9

51

nm

49

9.1

07

nm

Inte

nsity (

a.u

.)

Wavelength (nm)

49

8.1

73

nm

532nm excitationa)

496 497 498 499 500 501 502 5030

3000

6000

9000

12000

497.5

34nm

Inte

nsity (

a.u

.)

Wavelength (nm)

501.4

28nm

500.7

20nm

499.9

51nm

499.1

07nm

498.1

73nm

b) 355nm excitation

Confirmed by Ti particles only (in Ar atmosphere)

Discussion

• 355 nm laser line is actually

354.70nm.

– Resonant excitation

• Combine phase selective

LIBS and resonant

enhancement

– Phase-selectivity (particles only)

– Select lines or atoms to excite

– Enhance the emission signal

w 1F°

1.502 eV

2.506 eV

4.997 eV

Lase

r lin

e3

54

.70

2 n

m

Emis

sio

n li

ne

49

7.5

34

nm

a 1G

b 1D

Diagram for resonant excitation of the

titanium neutral atoms

Graphene Synthesis

Motivation

• Common methods for graphene/CNT/diamond synthesis include arc discharge, laser ablation, and chemical vapor deposition (CVD)

• But, large-scale applications require synthetic methods that are continuous, energy efficient, and do not require expensive starting materials

• Flame synthesis is scalable and offers potential for high volume production at reduced cost

• Flames readily provide temperatures and carbon speciesneeded for graphene/CNT/diamond growth

Details of Multiple IDF Burner

Air AirAirAir Air AirAir

Fuel Fuel FuelFuel FuelFuel FuelFuel

Pyrolysis Vapors

(Rich in Cn & CO)

Inverse

Diffusion

Flame

Air AirAirAir Air AirAir

Fuel Fuel FuelFuel FuelFuel FuelFuel

Pyrolysis Vapors

(Rich in Cn & CO)

Inverse

Diffusion

Flame

Honeycomb Structure

Oxidizer

Fuel

Flame Synthesis of Graphene on SubstratesO

X

i

d

i

z

e

r

F

u

e

l

O

X

i

d

i

z

e

r

F

u

e

l

O

X

i

d

i

z

e

r

F

u

e

l

O

X

i

d

i

z

e

r

F

u

e

l

O

X

i

d

i

z

e

r

F

u

e

l

F

u

e

l

Hydrogen +

Pyrolysis Vapors

Flame

Quartz

Extension/Nozzle

Graphene on Cu or Ni

Open to

Ambient

Memon N. K, Tse S. D, et. al. Flame Synthesis of Graphene Films in Open Environments. Carbon 2011; 49(15):5064–70.

Hydrogen + Pyrolysis Vapors

Few-layer Graphene on Cu or Ni

Flame

O

X

i

d

i

z

e

r

F

u

e

l

O

X

i

d

i

z

e

r

F

u

e

l

O

X

i

d

i

z

e

r

F

u

e

l

O

X

i

d

i

z

e

r

F

u

e

l

O

X

i

d

i

z

e

r

Flame Synthesis

Multiple

Inverse-

Flame

Synthesis

Burner

Hydrogen

Pretreat-

ment

Raman and PL

TDL Detector

Graphene Transfer

Srivastava A et. al. Chemistry of Materials 2010.

Raman Spectrum of Graphene

Ferrari, a; et al. Physical Review Letters 2006, 97, 1-4.

Kim, K. S. et. al. Nature 2009, 457, 706-10.

D peak at 1351 cm-1, which is

due to the first-order zone

boundary phonons and is

used to determine the

disorder present in the

graphene

G peak at 1580 cm-1, which is

related to the bond stretching

of sp2 bonded carbon atoms

2D peak at 2700 cm-1, which

is caused by the second-order

zone boundary phonons

Ratio between the intensities

of the G peak (IG) and the 2D

peak (I2D) provides an

estimate of the number of

layers

For mono and bi-layer

graphene, this ratio is

<1

If > two layers are

present, ratios ranging

from 1.3 to 2.4 have

been reported for FLG

Graphene Growth on Cu (950°C)

A B

20 μm1200 1400 1600 1800 2000 2200 2400 2600 2800 30000

1000

2000

3000

4000

5000

6000

7000

8000

9000

Raman Shift (cm-1)

Inte

nsi

ty (

a.u

.)

1400 1800 26002200

D

G

2D

C

1.71.3

Cu IG/I2D peak position

1.4 1.5 1.6

1 2 3 4 5 6 7 8 9 10 11

1

2

3

4

5

6

7

8

9

10

11

1.3

1.35

1.4

1.45

1.5

1.55

1.6

1.65

1.7

2 μm

D

400 450 500 550 600 650 70081

82

83

84

85

86

87

88

89

Wavelength (nm)550 650

Tran

smit

tanc

e (%

)

82

450

84

86

88E

50 100 150 200

0

-5

5

3.95 nm

Distance (nm)

He

igh

t (n

m)

100 nm

F

• IG/I2D peak provides an estimate of the number of layers

• FWHM of our 2D peak is 75 cm-1, consistent with FLG grown at atmospheric pressure

• Transmittance (2.3% per layer) of our FLG films at 550 nm is 86%, correlating to 6 layers

• AFM: 4nm thickness 4-8 monolayers of graphene

Graphene Growth on Cu – XPS

280 281 282 283 284 285 286 287 288 289 290 2910

1

2

3

4

5

6

7

8

9

10x 10

4

C - C C - O C = O

282 284 286 288 290

Inte

nsi

ty (

a.u

.)

250 300 350 400 450 5000.5

1

1.5

2

2.5

3

3.5

4

4.5

5

5.5

6x 10

5

C 1s

O 1s

Binding Energy (eV)

Binding Energy (eV)

Inte

nsi

ty (

a.u

.)

Bae, S.; et. al. Nature Nanotechnology

2010, 5, 1-5.

• H2O product at high temperatures can result in oxygen doping of graphene

• However, with abundant H2 present in the post-flame species, and at relatively ‘‘low’’

growth temperatures (950C), such oxidation reactions are minimized

• XPS of the C 1s peak (main peak at 284.4 eV) indicates that most of the atoms are in

the sp2 C state

• Less than 10% of oxygen incorporation (e.g. CO) less than that for CVD-grown

Graphene Growth on Ni, Co, Cu-Ni (850°C)

5 1/nm

B

1200 1400 1600 1800 2000 2200 2400 2600 2800 3000

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

1200 1400 1600 1800 2000 2200 2400 2600 2800 3000

-500

0

500

1000

1500

1200 1400 1600 1800 2000 2200 2400 2600 2800 3000-3000

-2000

-1000

0

1000

2000

3000

4000

5000

6000

Inte

nsi

ty (

a.u

.)

1400 1800 26002200

D

G2D

Raman Shift (cm-1)

Cu-Ni Alloy

Co

Ni

a b

150nm

70nm

50nm

ID/IG = C (λ) / La

• ID/IG is used as a metric for the disorder present in the graphene, which

develops from domain boundaries, wrinkles, edges, impurities, and other

factors

• A lower D peak, compared to that for Cu (~45nm), is observed for all three

substrates

• The relatively higher D peak for the Cu–Ni alloy is likely due to the presence

of Cu, and to the increased role of a surface growth mechanism

Experimental setup

P

R

E

C

U

R

S

O

R

F

U

E

L

O

X

I

D

I

Z

E

R

F

U

E

L

F

U

E

L

O

X

I

D

I

Z

E

R

F

U

E

L

O

X

I

D

I

Z

E

R

F

U

E

L

F

U

E

L

O

X

I

D

I

Z

E

R

P

R

E

C

U

R

S

O

R

F

U

E

L

Quartz enclosure

Cu Substrate

Pyrolysis Vapors

Photograph of multiple

inverse-diffusional-flame

Hydrogen flame

Open

atmosphere

Top view

G

D

2D

1350 1580 2700

IG/I2D=0.5 2D peak up-shifted 7 cm-1 and its FWHM = 39 cm-1

Characterization of Monolayer graphene films

The slight up-shift of 2D peak is caused by a small percentage of Bilayer films.

IG/I2D= 0.46

Characterization and Continuous Automation

of an Environmentally Green Primer

Tasks for Paste-Like Material

• Rheology

– Designed device for rheology measurement

– Study on placebo materials Device for filled weight study

– Designed device to fill cups and study weight variability

» First generation device (non energetics) was machined and studied

» Energetics filling device was machined and transferred

» Dosating study on placebo materials completed

• Modeling

– Implemented modeling method using DEM

Task for Slurry Materials

• Rheology

– Implemented technique for rheology measurement

– Started study on placebo materials

• Device for filled weight study

– Designed device to fill cups and study weight variability

» Device was transferred

» Study on placebo materials

• Modeling

– Implemented modeling method using CFD software

Characterization of

Pastes/Wet Powders

• GOAL: To find a placebo material that behaves similarly to

energetic material by matching packing behavior

• Placebo characterization was performed on a small scale (20-

100mg) and a larger scale (4-20g)

• Small scale compressibility experiments were performed at

Rutgers and at Picatinny using sister devices (ARES and

RDA-III)

• A novel small scale attachment was designed by Rutgers and

machined to perform compressibility tests on the ARES and

RDA-III

• Compressibility testing of live material was performed on the

Picatinny RDA-III

Characterization of

Pastes/Wet Powders

• Larger scale placebo characterization was performed at

Rutgers using a Freeman FT4 Powder Rheometer

• Compressibility results obtained by the ARES and RDA-III

were compared to FT4 results to validate the novel cup and

piston design

• Using the FT4, several characterization methods were

implemented to test the flow and packing properties of

placebo material: Compressibility, Permeability, Flow Energy,

Shear

Placebo

Glass beads

0

5

10

15

20

25

30

35

40

45

50

0.1 1 10 100 1000 10000

Vo

lum

e %

Size (micron)

Blue: 1-20 um

Orange: 53-45 um

Red: 106-90 um

Yellow: 300-250 um

Blue: 1-20 µm Orange: 53-45 µm Red: 106-90 µm Yellow: 300-250 µm

d10 (µm) 1 45 91 244

d50 (µm) 6 50 102 276

d90 (µm) 11 55 114 309

boy

Compressibility

• Measures cohesion by relating it to the amount of entrapped air

• Technique shows general correlation to particle size and therefore cohesion, but some exceptions exist

• Commercial equipment use vessels ranging from 10 to 85mL

• We have developed a test that uses ~30mg of material

– Cup size is 5mm in diameter and 1.5 –5mm in depth

• Procedure:– Sample is loaded into vessel

– Piston is lowered at a constant rate of 0.005mm/s

– The vertical position of and the force exerted on the piston is recorded in time

– The density of the powder bed as a function of applied normal stress is calculated

0.5

0.7

0.9

1.1

1.3

1.5

1.7

0 500 1000

De

nsi

ty (g

/cm

3)

Applied Normal Stress (kPa)

Compressibility:

FT4 vs Small Scale Cup and Piston

0

0.5

1

1.5

2

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Bu

lk D

ensi

ty

Applied Normal Stress

Yellow - Dry Yellow - 5%WaterYellow - 10%Water Yellow - 15%WaterYellow - 20%Water

0

0.5

1

1.5

2

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Bu

lk D

ensi

ty

Applied Normal Stress

Red - Dry Red - 5%waterRed - 10%water Red - 15%waterRed - 20%water

275micron

100micron

0

0.5

1

1.5

2

2.5

0 20 40

De

ns

ity (

g/c

m3

)

Stress (kPa)

100 microns

0% 5%

10% 15%

20%

0

0.5

1

1.5

2

2.5

0 20 40

De

ns

ity (

g/c

m3

)

Stress (kPa)

275 microns

0% 5%

10% 15%

20%

Compressibility:

FT4 vs Small Scale Cup and Piston

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Bu

lk D

ensi

ty

Applied Normal Stress

Orange - Dry Orange - 5%Water

Orange - 10%Water Orange - 15%Water

Orange - 20%Water

50micron

5micron

0

0.5

1

1.5

2

2.5

0 10 20 30 40 50

De

ns

ity (

g/c

m3

)

Stress (kPa)

50 microns

0% 5%

10% 15%

20%

0

0.5

1

1.5

2

2.5

0 10 20 30 40 50

De

ns

ity (

g/c

m3

)

Stress (kPa)

5 microns

0% 5% 10%

15% 20%

0

0.25

0.5

0.75

1

1.25

1.5

1.75

2

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Bu

lk D

en

sit

y

Applied Normal Stress (kPa)

As Received 2wt% Water5wt% Water 10wt% Water15wt% Water 17.5wt% Water20wt% Water 22.5wt% Water

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0 5 10 15 20

Bu

lk D

en

sit

y [

g/c

m3]

Piston Pressure [kPa]

DEM

FT4

EDEM Simulations – Dry Beads

Matching Compressibility Data

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0 5 10 15 20

Bu

lk D

en

sit

y [

g/c

m3]

Piston Pressure [kPa]

DEM

FT4

275 mm (within 1%)

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0 5 10 15 20

Bu

lk D

en

sit

y [

g/c

m3]

Piston Pressure [kPa]

DEM

FT4

100 mm (within 1%)

50 mm (within 2%)

EDEM Simulations – Dry Beads

Matching Compressibility Data

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 5 10 15 20

So

lid

s F

racti

on

Stress on Piston [kPa]

FT4 5% DEM, V = 0.1

FT4 10% DEM, V=0.2

0

0.2

0.4

0.6

0.8

0 5 10 15 20

So

lid

s F

racti

on

Stress on Piston [kPa]

ft4

DEM

100 micron

5%water

50 micron

Remarks

• The compressibility tests on the novel cup and piston devices

show that the live material match well with multiple placebos

• Cup filling with live material will be performed at Picatinny

• Cup filling experiments at Rutgers will be carried out with the

placebo material

• Simulations show comparable compressibility results and will

be used to perform cup filling simulations

PASTE CUP FILLING

95

EDEM of Dosating

A model created with DEM that pushes the collected particles out of the nozzle

(rose colored) by a plungers (purple) into a cup (green). The progression of

the plunger pushing the sample out of the tube and into the cup can be seen

from left to right for each tube size.

Placebo Cup Filling Device

Manual tests proved feasibility.

Able to fill 5 cups at a time and up to 100 cups.

Variability will depend heavily on the material properties.97

Machined dosating device

Energetic Cup Filling Device

99

Small Scale Dosating Device

Slurry Rheology

• Placebo viscosity was obtained using low and high viscosity

Brookfield DV-III Rheometers

• ARES Rheometer was used to obtain viscosity measurements

for MIC

• Contact angle and density were also obtained

• Using these properties, simulations can more accurately

represent the system

101

Placebo Study:

Effect of Nano-sized Alumina

Loading on Polymer Solutions

0

500

1000

1500

2000

2500

3000

3500

4000

0 100 200

Vis

co

sit

y (

cP

s)

Shear Rate (1/s)

In 1 wt% HPMC

1% 3%

5% 10%

wt%

0

500

1000

1500

2000

2500

3000

3500

4000

0 50 100 150 200 250

Vis

co

sit

y (

cP

s)

Shear Rate (1/s)

In 1wt% HEC

0% 1%

3% 5%

wt% Alumina

Slurry Cup Filling Simulations

• Using these properties, simulations can more accurately represent the system

• Slurry simulation velocity magnitude (m/s) (colors) and surface of slurry (gray).

105

Remarks

• Rutgers will be performing cup filling experiments with

placebos

• MIC cup filling to be performed by Picatinny

• Cup filling of MIC has been successfully performed by

Innovative Materials and Processes (IMP)

106

Post-docs

– Gang Xiong (synthesis, laser diagnostics)

– Zhizhong Dong (nanowire, nanoparticle synthesis)

– James Scicolone (green primer automation)

Graduate students

– Chris Stout (nanoparticle synthesis)

– Hua Hong (graphene synthesis)

– Bill Mozet (PLD)

– Michelle Lee (MD simulations)

Collaborators

– Keivan Esfarjani

Funding

– National Science Foundation

– Army Research Office

– U.S. Army

– DARPA

– Office of Naval Research

Acknowledgements