MATTEO PASQUALI - Stanford Universitygcep.stanford.edu/pdfs/iq9bO_1Ib0rRuH_ve0A2jA/Pasquali-20071102-GCEP.pdf · MATTEO PASQUALI Department of ... (Steel 2 GPa, PBO 5.7 GPa, Aluminum

MATTEO PASQUALIDepartment of Chemical & Biomolecular Engineering,

Department of Chemistry,Carbon Nanotechnology Laboratory,

The Smalley Institute for Nanoscale Science & TechnologyRice University, Houston, TX

[email protected]

QUANTUM WIRESFOR GRID APPLICATIONS

Advanced Electricity Infrastructure WorkshopGCEP, Stanford, CA, 1 November2007

OUTLINE

TeamEnergy challenge and power transmissionCarbon NanotubesArmchair Quantum Wire

Expected featuresProgress so far

Production of single-chirality nanotubes

Separation of nanotubesSpinning of nanotube fibers

Perspective

Rick Smalley

WadeAdams

TEAM

Team effortThough process initiated by Rick Smalley & Wade AdamsIdea of the AQW: Rick Smalley et al.

Multidisciplinary, integrated projectChemistry, Physics, Chem. Eng., Materials ScienceJim Tour, MP, Boris Yakobson, Andy Barron, Jun Kono,

Bob Hauge, Howard Schmidt, Wen-Fang Hwang, et al

Hauge

Tour

Schmidt

YakobsonHwang

Barron Kono

Humanity’s Top Ten Problemsfor next 50 years

1. ENERGY2. WATER3. FOOD4. ENVIRONMENT 5. POVERTY6. TERRORISM & WAR7. DISEASE8. EDUCATION9. DEMOCRACY10. POPULATION

2007 6.6 Billion People2050 9-11 Billion People

RICK SMALLEY’S LECTURE QUIZ

05

101520253035404550

Oil

Coal

GasFiss

ionBiom

ass

Hydroe

lectric

Solar, w

ind, g

eothe

rmal

0.5

2003

05

101520253035404550

Oil

Coal

GasFus

ion / F

ission

Biomas

sHyd

roelec

tric

Solar, w

ind, g

eothe

rmal

2050

Smalley’s Terawatt Challenge

14 Terawatts

210 M BOE/day30 -- 60 Terawatts450 – 900 MBOE/day

Energy:The Basis of Prosperity

20st Century = OIL21st Century = ??

THE ENERGY REVOLUTION

Source: International Energy Agency

SOLAR CELL LAND AREA REQUIREMENTS

Nate LewisCal Tech

Total average daily solar flux: 165,000 TW6 Boxes at 3.3 TW each = 20 TWBoxes are in deserts, far from population centers…

Sou

rce:

NR

EL

US RENEWABLE RESOURCES MAP

Biomass potential: negative energy balance?Harvesting of renewables far from population centers

GEO

BIO

SUN

WIND

Source: DOE & Nate Lewis, Caltech

Currently, power is generated close to population centers

US POWER PLANT MAP

Currently, power plants are near population centersReason: limitations on long-distance power transmissionNuclear is a potential alternative: undesirable near cities

GLOBAL ELECTRICAL ENERGY GRID

Idea of a global grid introduced by Buckminster Fuller (~1970)Will be made of Fullerenes?

ALLOTROPES OF CARBON

SWNT: ROLLED-UP SHEET OF GRAPHITE

Mic

hael

Strö

ck Chirality (n,m) identifiesthe species

(n,0) and (0,m): zig-zag(n,n): armchair(n,m): chiral

•Metallic: n = m (bandgap = 0 eV) •Semi-metallic: n – m is multiple of 3 (“mod 3 tubes,” bandgap ~1-10 meV)•Semiconducting: n – m is not a multiple of 3 (bandgap ~0.5 - 1.0 eV; HiPco 0.8-1.4 eV)

Current methods produce mixtures of metallic/semi-metallic (1/3rd) and semiconductors (2/3rd) Length is polydispersePhysical and chemical polydispersity

SWNTs AS A CLASS OF MATERIALS

SWNT PROPERTIESExceptional mechanical strength

Tensile strength > 37 GPa(Steel 2 GPa, PBO 5.7 GPa, Aluminum 0.3 GPa)Young modulus ~ 0.62 – 1.25 TPa(Steel 0.3 TPa, PBO 0.36 TPa, Aluminum 0.07 TPa)

Low density ~ 1.4 g/cm3(Steel ~8 g/cm3, PBO 1.6 g/cm3, Aluminum 2.7 g/cm3)

Electrical resistivity ~ 1 μΩ cm(Copper 1.7 μΩ cm, Silver 1.55 μΩ cm, Al 2.7 μΩ cm)

Thermal conductivity ~ 3000 W / m K(Diamond ~ 2000 W / m K)

The ultimate polymerThe ultimate carbon material

Review by Baughman et al., Science, 297, 787 (2002)

CONDUCTIVITY OF SWNTs

Measurements on individual metallic SWNT on Si wafers with patterned metal contactsSingle tubes can pass 20 uA for hoursEquivalent to roughly a billion amps per square centimeter!Conductivity measured twice that of copperBallistic conduction at low fields with mean free path of 1.4 micronsSimilar results reported by othersDespite chemical contaminants and asymmetric environment

Dekker, Smalley, Nature, 386, 474-477 (1997). McEuen, et al, Phys.Rev.Lett.84, 6082

RESONANT QUANTUM TUNNELING

Conductance in parallel end-to-end contact ~ single SWNTMisalignment reduces conductance (up to ~10 times)

Buldum and Lu, Phys. Rev. B 63, 161403 R (2001).

Cable of all-aligned armchair SWNTsExceptional potential current carrying capacity

Estimated >1 Billion Amps / cm2 (McEuen et al, IEEE Trans.

Nanotech., 1, 78, 2002)Current technology (steel reinforced aluminum) has1000-5000 Amps / cm2

Combination ofHigh electrical conductivity (~ twice copper at RT)High thermal conductivity (~ diamond)High stiffness: Young Modulus ~0.6-1 TPaSteel 0.3 TPa, Aluminum 0.07 TPa

Low density: 1.4 g/cm3

Steel 8 g/cm3, Aluminum 2.7 g/cm3

THE ARMCHAIR QUANTUM WIRE

Review by Baughman et al., Science, 297, 787 (2002)

ARMCHAIR QUANTUM WIRE PROJECTExpected Features1-10x Copper Conductivity6x Less MassStronger Than SteelZero Thermal Expansion30x Power Density vs. Cu/Al

Key Grid BenefitsReduced Power LossLow-to-No Sag Reduced MassHigher Power Density

SWNT Technology BenefitsType & Class SpecificHigher PurityLower CostPolymer Dispersible

EXPECTATIONS: AQW ON THE GRID

Key Benefits• Eliminate Thermal Failures• Reduce Wasted Power• Reduce Urban R.O.W. Costs• Enable Remote Generation

MAKING THE AQW

What needs to be done:Go from single SWNTto macroscopic material

All-armchair SWNTspreferably all same type

Large quantityAlign and transform into fiber

THREE WAYS OF GETTING IT DONE

Route #1:Sort large amount of armchair SWNTsProcess into fibers

Route #2:Sort minute amount of armchair SWNTsCloneProcess into fibers (maybe on the fly)

Route #3:Grow directly SWNTs of single-chirality by tuning catalyst (variant of cloning)

Process into fibers (maybe on the fly)

ARMCHAIR QUANTUM WIRE PROJECT

initialSWNTsupply

HiPcoCoMoCATLaser-oven

Carpets…

sorting&

separations

1 ng

1 g(enriched)

cutting&

cloning100 X

7 pass:100 kg

1%

99%

fiberspinning

modulusstrength

densityelectrical cond.

thermal cond.

property maps

y

x

applicationsprototype

applications

Selective elimination by electrical breakdown –Collins et al., Science 2001

Covalent functionalization – Strano et al., Science 2003Selective adsorption – Chattopadhryay et al., JACS 2003Ion exchange chromatography – Zheng et al., Science 2003Electrophoresis – Heller et al., JACS 2004Density gradient ultracentifugation –

Arnold et al., Nature Nanotech. 2006Dielectrophoresis – Krupke et al., Science 2003

Separation very difficultLow solubilityMinimal physicochemical differences (except DEP)

Some methods appear scalable, but not highly selectiveOther methods have high selectivity, poor scalability Modeling may help scale-up

SOA: SWNT TYPE SEPARATION METHODS

DENSITY GRADIENT ULTRACENTRIFUGATION

Sort by density SWNTs of different diameterhave (slightly) different density

Does not quite sort by typePossible when few SWNTs present(e.g., CoMoCAT)

Arnold et al, Nature Nanotech,1, 60 2006Hersam

SOA: SINGLE-CHIRALITY CATALYTIC GROWTH

Growth of single type from specific catalystCurrent opinion: SWNTs grow out of liquid metal droplets (catalyst)Droplet (particle) size controls SWNT sizeNarrowest distribution: CoMoCAT

Templated substrateSelectivity by diameter

How to go from diameter to type?

HiPco

CoMoCATResasco

SOA: SEEDED GROWTH/CLONING

Amplification of SWNTsDocking: reduce catalyst particle at endof SWNT with minimal etching,leaving activated catalyst in intimatecontact with SWNT

Growth: cause the seed to growin a CVD chamber. LongerSWNT should be identical to originalone (seed)

Smalley, Tour, Barron, et al, Rice U

Smalley et al, JACS 2006

Seed: 200nm long; amplified: 6.7 μm longSeed and amplified SWNT have same diameter (~0.7 nm)Same chirality not yet provenLow yield: few seeds regrow on surfaces; looking for alternatives

SOA: SEEDED GROWTH/CLONING

SOA: SPINNING OF SWNT FIBERSFour main methods

From water-surfactant suspension (Poulin et al, CNRS Bordeaux)General route; SWNT manufacturing unimportantSome surfactant/polymer may remain in fiber

From a carpet/forest (Baughman et al, UT Dallas)Will be great if cloning is done on carpetsWorks for long CNTs (~1 mm OK)Never demonstrated on SWNTs

From gas-phase reactor (Windle et al, Cambridge)Will be great if “magic” catalyst can be foundWill work for long SWNTs (~1 mm OK)

From LC solution (Rice U)General route; SWNT manufacturing unimportantWill work for medium-length SWNTs(~1 μm proven, maybe ~10 μm)

Baughman

Poulin

Windle

SPINNING FIBERS FROM WATER-SURFACTANTPoulin et al, CNRS Bordeaux

Vigolo et al, Science 290, 1331 (2000)

25 μm

hydrophobic(C-12 chain)

SWNT

charged group(sulfate)

SPINNING FIBERS FROM A CARPETBaughman et al, UT Dallas

Zhang et al, Science 306, 1358 (2004)

DIRECT FIBER SPINNING FROM FURNACEWindle et al, U Cambridge (UK)

Li et al, Science 304, 276 (2004)

SWNT-ACID LIQUID CRYSTAL

Acid protonate the SWNTs: stabilizationA liquid crystal forms at high SWNT

concentrationSimilarities with rodlike polymers (Kevlar)Liquid crystal morphology depends on

type of acid (sulfuric vs. chlorosulfonic)Stable for months; no chemical reactions

7% wt in ClHSO3, cross polars, 0 and 90°

20 μm

DILUTE SEMIDILUTE

ISOTROPICCONCENTRATED

LIQUIDCRYSTALLINE

Ramesh et al, J. Phys. Chem. B, 2004Davis et al, Macromolecules, 2004

600 ppm wt. 6% wt.

FIBERS FROM SWNT/ACID

Highly aligned fibers; diameter ~20-70 μmContinuous process

Ericson et al, Science, 2004

TYPICAL ACID-SPUN SWNT FIBER

Excellent macrostructurePoor mesostructure (bundles), will affect transport

Ø=37±3µm

Ø=50±2µm

ASSESS WAYS OF GETTING IT DONE

Route #1:Separate large amount of SWNTsProcess into fibers

Large scale separation for fiber spinningWe need a miracle (breakthrough)We know a few places where to look

Flow-dielectrophoresisSelective reactions

Fiber spinningWe have two routes: surfactant, acidEach needs scientific engineering

Flow-DEP

Route #2:Separate minute amount of SWNTsCloneProcess into fibers (maybe on the fly)

Small scale separationWe have a route: CoMoCAT

+ density gradient ultracentrifugationCloning

Concept ~ proven (on surfaces, chirality?)We need a miracle (breakthrough)We know where to look

Fiber spinningTwo routes: surfactant, acidMaybe carpet and/or direct

ASSESS WAYS OF GETTING IT DONE

Route #3:Grow directly SWNTs of single-chirality by tuning catalyst (variant of cloning)

Process into fibers (maybe on the fly)Most elegant route

Fundamental understanding of SWNT growth still evolving

Current understanding:liquid phase catalystdiameter selectivity possible

type selectivity unlikelyFiber spinning

Two routes: surfactant, acidMaybe carpet and/or direct

ASSESS WAYS OF GETTING IT DONE

liquid C

gas

SUMMARY ASSESSMENT

Direct single-chirality growthWe need a miracleWe don’t know where to look

CloningSort-of proven (surface, chirality?)We need a miracleWe know where to look

Fiber spinningWe have four routesNeed scientific engineering

NeedBright, enthusiastic peopleFunding

Humanity’s Top Ten Problems for next 50 years

1. ENERGY2. WATER3. FOOD4. ENVIRONMENT 5. POVERTY6. TERRORISM & WAR7. DISEASE8. EDUCATION9. DEMOCRACY10. POPULATION 2003 6.5 Billion People

2050 10-12 Billion People

RICK SMALLEY’S LECTURE QUIZ

POPULATION

National Geographic Nov 2002

POPULATION

For the first time in history, we now live in a small island

Fully connected, interdependent

Nowhere to go (for a long time)

Insular civilizations (Jared Diamond)

Expanded and overtaxed environment until they collapsed

Learned to control harvest rate and limited population

Technology only makes the problem worse

Creates transient “excess” of resources

Albert Bartlett, “The Essential Exponential”

If then kxdtdx

=0 ,)(lim >∀∞=

∞→ktx

t Bartlett

Diamond

POPULATION

Quick mnemonic: at k% growth rate, the doubling timeis Td = 100 ln2/k = 70/kAt 1% population growth rate:

At 2 kW/person, we run out of solar power in 1) 100 years (AD 2100)2) 1,000 years (AD 3000)3) 10,000 years (AD 12000)4) 100,000 years (AD 102,000)5) Ridiculous: we cannot possibly run out of solar power!

POPULATION

Quick mnemonic: at k% growth rate, the doubling timeis Td = 100 ln2/k = 70/kAt 1% population growth rate:

At 2 kW/person, we run out of solar power in 1) 100 years (AD 2100)2) 1,000 years (AD 3000)3) 10,000 years (AD 12000)4) 100,000 years (AD 102,000)5) Ridiculous: we cannot possibly run out of solar power!

At that time, we will have 2 m2/person of space!At 0.5% population growth rate, we run out of solarpower (and space) in AD 4000!

POPULATION

Current estimates predict that population growth will stopin about 70 years

Estimates of population growth are highly inaccurate beyond average life expectancy (currently ~ 65 yr)

Situation is better now than in the 1960s

We need to remain conscious of it

PREDICTED

CONTRIBUTORS

PhD Students: Virginia Davis, Lars Ericson, Hua Fan, Nick Parra-Vasquez, Richard Booker, Yuhuang Wang, Naty Behabtu

UG Students: J. Sulpizio, Valentin Prieto, Jason Longoria, Robby Pinnick, Jon AllisonPostdocs: Pradeep Rai, Haiquing Peng, S. Ramesh, Rajesh Saini, Micah GreenScientists: Carter Kittrell , Wen-Fang Hwang, Howard SchmidtRice Faculty: Boris Yakobson, Ed Billups, Wade Adams, Robert Hauge, Rick SmalleyU. Penn: Jack Fischer, Karen Winey, Wei Zhou, Juray Vavro, Cszaba Guthy

ACKNOWLEDGEMENTSFUNDING

Office of Naval Research / DURINTAir Force Office of Scientific ResearchAir Force Research LabNational Science FoundationNASA Welch FoundationTexas Advanced Technology Program

REFERENCES (email [email protected])Phase Behavior and Rheology:

Davis et al., Macromolecules, 37, p. 154 (2004)Zhou et al., Phys. Rev. B, 72, 045440 (2005)Pasquali et al., US Patent 6,962,092 (2005)Parra-Vasquez et al., Macromolecules, 40, p. 4043 (2007)

Solubility and Protonation:Ramesh et al., J. Phys. Chem B, 108, p. 8794 (2004)Rai et al., J. Am. Chem. Soc., 128, p. 591 (2006)

Fiber Spinning and PropertiesEricson et al., Science, 305, p. 1447 (2004)Wang et al., Chem. Mater., 17, p. 6361 (2005)Smalley et. al., US Patent 7,125,502 (2006)

RICK SMALLEY

Be a scientist, save the world!