Scale-Up of Carbon Nanotube Synthesis at the Jefferson Lab
Free Electron Laser: From Research to Production
4The College of William and MaryDepartment of Applied Science
Michael W. Smith1, Kevin Jordan2, Cheol Park3, Michelle Shinn2, Brian Holloway4,
1NASA Langley Research Center
2Thomas Jefferson National Accelerator Facility
Funding by NASA AMPB, ASOMB, C&I,ONR, State of Virginia, Luna Innovations
3National Institute of Aerospace (NIA) - NASA
Why Make Carbon Nanotubes with the Jefferson Lab FEL?
Laser Ablation/Oven technique makes the “best” material, but in tabletop form is limited to small quantities (<= 200 mg/hour with a typical pulsed Nd:YAG laser apparatus)…
Jlab FEL is unique, it has:⇒ High average power (up to 10 kW)⇒ Tunable wavelength⇒ Underlying ultrafast pulse structure (sub-picosecond
pulses at 9 MHz for the current work)
…can this give a high volume stream of nanoparticulate catalyst and highly excited carbon stock for nanotube formation?
150 µm10 nsec = 10 feet
FEL
Ultr
afas
t Abl
atio
n
10-1
00 n
sec
Abl
atio
n
km’s/sec
four pulses
Desirable Nanotube Properties for Multi-functional Fiber-Reinforced Composites, (etc.)
Single wall.Long. High Quality (clean, straight, defect-free walls).Pure/Purifiable.Dispersable.Specific Chirality (conduction and sensing).Specific Diameter (bonding and intermolecular interactions)
Low “Quality” Nanotubes(bulk Chinese product)
Image Credits: Dr. Roy Crooks (Swales/NASA LaRC), Contributed via Cheol Park (NIA/NASA LaRC)
High Res SEM, 2005 FEL Raw Material
Image Courtesy: Ron Quinlan, College of William and Mary
High Res SEM, 2005 FEL Raw Material
Image Courtesy: Ron Quinlan, College of William and Mary
High Resolution TEM (2001) FEL MaterialShows Single Walls of Individual Tubes
Original Front-Pumped Chamber (2000-2001)
Vacuum chamber (1000 C, 500 torr)1” dia. Graphite/catalyst target
NanotubeFormation Vortex
Input FEL beam
Plasma plume
Argon drift flow
Schematic of First Side-Pumped Synthesis Chamber (2001, shutdown)
Chamber (1000 C, 760 torr)
Argon heater
Graphite/catalyst targetSpindle
NanotubeSprayInput FEL beam
Plasma plume
Sonic nozzle
Schematic RF-Induction Heated Side-Pumped Synthesis Chamber (2005-present)
1.
2.
5.
1. Graphite core2. Insulation3. Purge vessel4. Purge gas5. 3.5 kW RF coil6. Insulation7. Spindle8. Target w/catalyst9. Orifice plate10. Porous plug
heater11. Pyrometer port12. Input FEL beam13. Nanotube spray
3.
6.
7.8.
9.10.
11.
13.
4.
12.
Chamber Core with Orifice Plate
7.5 kW Induction Heater with Graphite Test Block
Apparatus, Overhead View
FEL Beam Path
Chamber, Hot Zone
Target Loading
Chamber, Upstream End
Chamber, Upstream End
8/05, Rig installed in Lab 1
8/05, Rig installed in Lab 1
8/05, Opening Production Collector
8/05, Collector with 1 gram raw SWNT
8/05, Laden Collector
8/05, Cleaning Collector
8/05, Couple of grams of raw SWNT
8/05, Raw SWNTs in the jar, One Hour Exposure, Yield ~10%
4/05/06, 7.5 grams Raw Material Collected1.25 Hour Exposure, Est. Yield 50-80%
4/05/06, Used Target, 75 Minutes Elapsed Time
Fresh Target
Expended Target
SEM of Current High Yield Raw Material on Holey Carbon Substrate
…A Brief Digression on the Application of Raman Spectroscopy to the Analysis of Single Walled Carbon
Nanotubes…
High Res SEM, June 2005 Raw Material
Image Courtesy: Ron Quinlan, College of William and Mary
Laser Purification of August 2005 SWNT, 785 nm
10% power, dirty spot, 8.26.05.630_2
-0
50
100
150
200
250
300
350
400
Int
50 X after 5sec 100%
-0
50
100
150
200
250
300
350
400
Int
500 1000 1500 2000 2500 3000 Raman shift (cm-1)
Raman spectrum from low yield raw material
Raman spectrum from modified raw material
(purified by 785 nm irradiation)
Laser Purification of August 2005 SWNT, 785 nm
10% power, dirty spot, 8.26.05.630_2
-0
50
100
150
200
250
300
350
400
Int
50 X after 5sec 100%
-0
50
100
150
200
250
300
350
400
Int
500 1000 1500 2000 2500 3000 Raman shift (cm-1)
G Band to D band ratio is a measure of sample purity…
this one’s pretty low, ~3:1, wantto see more like 100:1
G
D
D Band is measureof amorphous carbon
content
Laser Purification of August 2005 SWNT, 785 nm
10% power, dirty spot, 8.26.05.630_2
-0
50
100
150
200
250
300
350
400
Int
50 X after 5sec 100%
-0
50
100
150
200
250
300
350
400
Int
500 1000 1500 2000 2500 3000 Raman shift (cm-1)
G
High Energy Band for SWNT’s hastwo peaks (not multiwall). G1 is
Around 1590 cm-1 (less for MWNT)
Laser Purification of August 2005 SWNT, 785 nm
10% power, dirty spot, 8.26.05.630_2
-0
50
100
150
200
250
300
350
400
Int
50 X after 5sec 100%
-0
50
100
150
200
250
300
350
400
Int
500 1000 1500 2000 2500 3000 Raman shift (cm-1)
Position of RBM (RadialBreathing Mode)
indicatesSWNT diameter
Laser Purification of August 2005 SWNT, 785 nm
10% power, dirty spot, 8.26.05.630_2
-0
50
100
150
200
250
300
350
400
Int
50 X after 5sec 100%
-0
50
100
150
200
250
300
350
400
Int
500 1000 1500 2000 2500 3000 Raman shift (cm-1)
Raman spectrum from low yield raw material
Raman spectrum from modified raw material
(purified by 785 nm irradiation)
Eight Position Sampling Chimneys Used for Fast Optimization Runs
Eight Position Sampling Chimneys Used for Fast Optimization Runs
G band Rises with Increasing Spin Rate at High Metal Catalyst Fraction
-0
200
400
600
800
1000
1200
1400
1600
1800
2000
2200
2400
Ram
an in
tens
ity
500 1000 1500 2000 2500 3000 Raman shift (cm-1)
12 Hz Rotation Rate
0.5 Hz Rotation Rate
Dylon Target, Ni:Co 2:2 atomic percent catalyst
G band Drops with Increasing Spin Rate at Low Metal Catalyst Fraction
4
-0
100
200
300
400
Int
5
-0
100
200
300
400
Int
6
-0
100
200
300
400
Int
500 1000 1500 2000 2500 3000 Raman shift (cm-1)
Dylon Target, Ni:Co 0.5:0.5 atomic percent catalyst
12 Hz Rotation Rate
0.5 Hz Rotation Rate
6 Hz Rotation Rate
Target Grain, Dylon vs. EDM GraphiteOptical Microscopy of Ablated Surface
Beam Track ~100 µm
1 mm 1 mm
SEM/EDS Image of Dylon/Phenolic Resin Target(carbon dark, metal catalyst is light)
Image Courtesy Jianjun Wang, College of William and Mary
SEM/EDS New, Fine-Grained Target(carbon dark, metal catalyst is light)
Image Courtesy Jianjun Wang, College of William and Mary
Raman Spectra, March 1-2, 2006
3.02.06chmn1
10
Int
3.02.06chmn1b
0 500In
t
3.2.06chmn1c
-0 1000In
t
3.02.06chmn2
-0 200In
t
3.02.06chmn3
-0
200
Int
3.02.06chmn4
10 Int
3.2.06chmn5
0
100
Int
3.2.06chmn6
-0 50
Int
3.2.06chmn7
-0 100In
t
3.2.06chmn 7b
-0 50
Int
3.2.06dst_near
10 Int
3.2.06dst_far
-0 100
Int
3.01.06tubeflake
-0 100In
t
3.01.06tubescrapings
-0
Int
500 1000 1500 2000 2500 3000 Raman shift (cm-1)
March 2006, Raman Spectra, Chimneys 1,6,7
3.2.06chmn1c
0
500
1000
1500
Int
3.2.06chmn7
-0
50
100
150
Int
3.2.06chmn6
-0
20
40
60
Int
200 400 600 800 1000 1200 1400 1600 Raman shift (cm-1)
Highest spin rate 18hz = 1080 RPM, loosest focus (+5.5 cm)
Lowest spin rate, tight focus
Used Target, March 06, Showing Thermal Damage
Comparison of FEL Synthesis with Commercial Methods
raw_HIPCO_3.11.05
-0
2000
4000
Int
3.15.06.9pm_prod
-0
500
1000
1500
Int
4.5.06.prod.cu
500
1000
1500
Int
carbolex_rcvd_01
500
1000
Int
500 1000 1500 2000 2500
Raman shift (cm-1)
HipCO (Hi pressure CO CVDw/Gas Phase Catalyst)
FEL Laser Ablation, 6 g/hr run
FEL Laser Ablation, variation
Arc Discharge, Carbolex
Comparison of FEL Synthesis with other Commercial Methods (4/5/06)
raw_HIPCO_3.11.05
-0
2000
4000
Int
3.15.06.9pm_prod
-0
2000
4000
Int
4.5.06.prod.cu
-0
2000
4000
Int
carbolex_rcvd_01
-0
2000
4000
Int
500 1000 1500 2000 2500
Raman shift (cm-1)
HipCO (Hi pressure CO CVDw/Gas Phase Catalyst)
FEL Laser Ablation
FEL Laser Ablation, variation
Arc Discharge, Carbolex
Latest Comparison of FEL Synthesis with Unpurified HipCO (4/12/06)
raw_HIPCO_3.11.05
1000
2000
3000
4000
5000
Int
4.12.06.prod.drker_area
1000
2000
3000
4000
5000
Int
4.12.06.prod.can_bottom
1000
2000
3000
4000
5000
Int
200 400 600 800 1000 1200 1400 1600 1800 Raman shift (cm-1)
HipCO (Hi pressure CO CVDw/Gas Phase Catalyst)
FEL Laser Ablation, 2 g/hr run
FEL Laser Ablation, variation
Latest Comparison of FEL Synthesis with Unpurified HipCO (4/12/06)
raw_HIPCO_3.11.05
1000
2000
3000
4000
5000
Int
4.12.06.prod.drker_area
1000
2000
3000
4000
5000
Int
4.12.06.prod.can_bottom
1000
2000
3000
4000
5000
Int
200 400 600 800 1000 1200 1400 1600 1800 Raman shift (cm-1)
HipCO (Hi pressure CO CVDw/Gas Phase Catalyst)
FEL Laser Ablation
FEL Laser Ablation, variation
Variability of Radial Breathing ModesComparison of FEL with other Methods
raw_HIPCO_3.11.05
0
1000
2000
3000
Int
3.15.06.9pm_prod
200
400
600
800
Int
4.5.06.prod.cu
200
400
600
Int
carbolex_rcvd_01
500
1000
Int
100 150 200 250 300 350
Raman shift (cm-1)
HipCO (Hi pressure CO CVDw/Gas Phase Catalyst)
FEL Laser Ablation
FEL Laser Ablation, variation
Arc Discharge, Carbolex
FEL CNT RBM (tube diameter) Variations with Wavelength and Focusing Condition
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
850
900
950
Ram
an in
tens
ity
140 160 180 200 220 240 260 280 300 Raman shift (cm-1)
1.6 µmat thresh
1.6 µmabove thresh
2.8 µmat thresh
1.6 µmat tightfocus
Engineering:Demonstrated high yield, HipCo-level-quality SWNT production at a production rate of 2-10 g/hour (10 to 50 X HipCo or Nd:YAG synthesis rates) at ~750 Waverage power, at 1.6 micron.
Developed specialized fine-grain FEL CNT target made in-house for < $10/lb.
Developed RF-heated laser oven apparatus (flow geometry, heat transfer/temperature distributions, target holder, production and sampling collectors, scanning and other remote controls, and visualization).
Physics:Found that the highest average yield is always at “incipient extinction”(the largest laser spot size before the plasma goes out.)
Found that the highest yield flakes of raw material always contain the smallest diameter tubes (the “smoking gun” pointing to ultrafast ablation effects).
Showed that RBM (tube diameter) varies with laser condition at a given wavelength as well as with wavelength.
Conclusions
Production at 750 W quasi cw is now routine, and will continue as required, but main focus will be on scale-up with:
Shorter Wavelengths and Higher Power (and more temporal stability)!
----------------
Projections?
At least 20-40 g/hour of highest grade material, ~5 times more forlesser grades (straight linear extrapolation).
“Designer” tubes with selectable diameter. (length?, chirality?)
More access to higher quality tubes with more choice regarding important properties => real progress in applications.
Future