Lawrence T. DrzalLawrence T. Drzal

Dept of Chemical Engineering and Materials ScienceComposite Materials and Structures Center

Michigan State UniversityEast Lansing, MI-48824

drzal@egr.msu.edu

I) Exfoliated Graphite NanoI) Exfoliated Graphite Nano­­Platelets and Platelets and II) Metal Nano Particles as II) Metal Nano Particles as

Multifunctional Materials for Polymers Multifunctional Materials for Polymers and Energy Storageand Energy Storage

NANO Material Portfolio

Halloysite Nanotubes

Cellulose Nanowhiskers

0.3 nm

NanoGraphite Platelets

Nanoclay

Boron Nitride NanoPlatelets

Vapor Grown Carbon Fibers

Carbon Nanotubes

Boron Nitride Nanotubes

Graphite NanoPlatelets ­ xGnP

3.35 Å

Carboxyl

PyroneLactone

C

O

C OO

OH

O

OH

OOH Hydroxyl

CarbonylNHNH2

Amine Imine

• Layered Natural Mineral

• Layers can be intercalated and exfoliated into nanosize platelets with high aspect ratio

• Basal Plane is inert (sp2 + π)• Existence of functional groups

at the edges can lead hydrogen or covalent bond with polymer matrix

• Nanocomposite propertiesmechanical, electrical, thermal and barrier properties

• Estimated Cost <$10/lb7nm

Nanoreinforcements & PropertiesNanoreinforcements & Properties

1.5 g/cm3

8 – 16 x 10-6

insulator

insulator1010 Ω cm

10 GPa

~ 130 GPa

Hydrogen Bond

Cellulose

Needle-Whisker

Cellulose Nanowhisker

~2.0 g/cm3

~1 x 10-6

conductor ~3000W/m K

insulator

?

~1 TPa

Hydrogen bond

Boron Nitride

PlateletCylinder

Exfoliated h-BNBN Nanotubes

NT 1.2 – 1.4 g/cm3

VGCF 1.8-2.1 g/cm3

-1 x 10-6

3000 W/m K (NT)20-2000 W/m K (VGCF)

NT ~ 50 x 10-6 Ω cmVGCF 5-100x10-3 Ω cm

(NT 180 GPa)VGCF 3-7 GPa

NT 1.0-1.7 TPaVGCF 0.25-0.5 TPa

π - π

Graphene(chair, zigzag, chiral)

CylinderNT ~1nm X 100nm

VGCF ~20nm X 100um

Carbon NanotubeVGCF

2.8 – 3.0 g/cm3

8 – 16 x 10-6

6.7 x 10-1 W/m K

1010 – 1016 Ω cm

~1 GPa

0.17 TPa

Hydrogen bondDipole-Dipole

SiO2, Al2O3, MgO,

K2O, Fe2O3

Platelet~1nm x 100nm

Exfoliated Clay

~(10-20 GPa)TENSILE STRENGTH

-1 x 10-6 29 x 10-6

COEF. THERMAL EXP.

3000 W/m K 6 W/m K

THERMAL CONDUCTIVITY

GraphiteNanoPlatelets

~2.0 g/cm3DENSITY

~ 50x10-6 Ω cm~ 1 Ω cm

ELECTRICALRESISTIVITY

~1.0 TPaTENSILE MODULUS

π - πINTERACTIONS

GrapheneCHEMICAL STRUCTURE

Platelet~1nm X 100nm

PHYSICAL STRUCTURE

Multifunctionality Attainable with xGnP

– Mass Reduction (low density, low concentration)– Increased Stiffness (high aspect ratio)– Increased Toughness (engineered interfacial adhesion)– Electrical Conductivity (electrostatic dissipation, electrostatic

painting, electromagnetic shielding)– Thermal Conductivity (lower C.T.E., higher Tult)– Improved Appearance (scratch resistance)– Barrier to Permeants (platelet morphology)– Reduced Flammability (less combustible material)– Surface Conductivity (controlled deposition and alignment)– Intra and Interlaminar Strengthening and Toughening– Composite Transverse Properties

Thermal Conductivity

00.10.20.30.40.50.60.70.80.9

1

ControlEpoxy

3 vol% MWEx.Gr

3 vol% CF 3 vol%VGCF

3 vol% CB

(W/g

*K)

Flexural Modulus of Nylon 6 Composites

0

2000

4000

6000

8000

10000

12000

14000

0 5 10 15 20 25[Vol%]

[MPa

]

xGnP-1xGnP-15CFGFVGCFNanomer I34.TCNCloisite 93A

Flexural Strength of Nylon 6 Composites

0

50

100

150

200

250

0 5 10 15 20 25[Vol%]

[MPa

]

xGnP-1xGnP-15CFGFVGCFNanomer I34.TCNCloisite 93A

Permeability of Nylon 6 Films

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

5 10 15 20 25 30 35 40[Hour]

[cm

3/m

2*da

y*at

m]

Control N63v%xGnP-15um/N63v%xGnP-1um/N63v%CF/N63v%GF3v%VGCF/N63v%Nanomer/N63v%Cloisite/N6

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

-1.00 0.00 1.00 2.00 3.00 4.00 5.00

Log(Freq/Hz)

Log(

Z/oh

m*c

m)

Control Epoxy1.0Vol% Exfoliated Gr2.0Vol% Exfoliated Gr3.0Vol% Exfoliated Gr

Static DissipationElectrostatic Painting

EMI/RFI Shielding

xGnP + Thermoset & Thermoplastics

3.35 Å

Carboxyl

Pyrone Lactone

C

OC O

O

OHO

OH

OOH Hydroxyl

CarbonylNHNH2Amine Imine

xGnP Nanoparticles Applied to Carbon Fiber Surfaces in Epoxy Composites

Flexural Strength in Transverse Direction

0

10

20

30

40

50

60

70

80

90

100

Control xGnP Coated sample

[MPa

]

Short Beam Shear Strength

0

10

20

30

40

50

60

70

80

90

100

Control xGnP Coated sample

[MPa

]

Flexural Modulus in Transverse Direction

0

1

2

3

4

5

6

7

8

9

10

11

Control xGnP Coated sample

[GPa

Mechanical and Electrical Properties Mechanical and Electrical Properties of Glass fiber/CaCOof Glass fiber/CaCO33 /UPE/UPE

A= 28%(glass fiber) + 47% (CaCO3) + 23%(UPE)= composite (xGnP™ 0%)

B= 28% (glass fiber /1.0% xGnP™­1) + 47% (CaCO3) +23%(UPE)= composite (xGnP™ 0.3%)

C= 28% (glass fiber) + 47% (CaCO3 /2.1% xGnP™­1) +23%(UPE)= composite (xGnP™ 1.0%)

D= 28% (glass fiber) + 47% (CaCO3 /3.2% xGnP™­1) +23%(UPE)= composite (xGnP™ 1.5%)

E= 28% (glass fiber) + 47% (CaCO3 /4.3% xGnP™­1) +23%(UPE)= composite (xGnP™ 2.0%)

F= 28% (glass fiber) + 38% (CaCO3 /10% xGnP™­1) +29%(UPE)= composite (xGnP™ 3.8%)

753 728649692

417

665

0

200

400

600

800

1000

A B C D E F

Impa

ct s

treng

th (J

/m)

0

2

4

6

8

10

0 1 2 3 4xGnP-1 wt.%

log

(Res

istiv

ity) (

R in

Ohm

s.m

)

0

2

4

6

8

10

12

log

(Res

istiv

ity) (

R in

Ohm

s/sq

)

Volume resistivitySurface resistivity116132157124119113

1816

18 19 1919

0

40

80

120

160

200

240

A B C D E F

Flex

ural

stre

ss (M

Pa)

0

5

10

15

20

25

30

Flex

ural

mod

ulus

(GPa

)Stress ModulusStrength Modulus

Flex

ural

str

engt

h

Metal NANO­Particles + Nanographite Platelets

Size (0.5 – 10nm)Composition

ConcentrationDispersion

Metal Nanoparticles

SizeUtilization

CompositionDistribution

SizeSurface Chemistry

Dispersion

xGnP + NanoparticlexGnP

xGnP-supported Pt catalysts in various sizes produced by MSU techniques

hydrophobic/hydrophilic xGnP dispersed in water

(300-500um) (300-500 um) (15-100 um) ( < 1um) 3~4nm 2~3nm

1~2nm < 1nm

Surface chemistry

control

Drzal Group methodConventional

60wt.% Pt 60wt.% Pt

Metal NANO Particles on Graphene

Pt Ru

Pd PtRu Au

0

10

20

30

40

50

60

1.0~1.5 1.5~2.0 2.0~2.5 2.5~3.0 3.0~3.5 3.5~4.0

Particle size (nm)

Freq

uenc

y (%

)

Metal Nanoparticles on Graphene and other Surfaces

Commercial Pt/CB Pt/CB-MSU

Pt/SWNT-MSU Pt/MWNT-MSUPt/GNF-MSU

MSU synthesize smaller particles with better dispersion on any MSU synthesize smaller particles with better dispersion on any carbon surface without a harsh pretreatmentcarbon surface without a harsh pretreatment

Advantages of MSU process

Advantages of xGnP over other state­of­the­art carbon materials?• The highest oxidation resistance and the highest crystallinity• The low impurities• The most cost­effective• The morphology to enhance contact with reactants

Advantages of MSU technique in depositing nanosized metals and oxides?• Simple, fast and economical process • Easy to tune the size / dispersion of metals• Versatile to apply for any solid support, • Highly active, large surface to volume ratio and easily accessible

+

Hydrogen StorageHydrogen StorageFuel CellsFuel Cells SupercapacitorsSupercapacitors BatteriesBatteries

1. Pt, Pd1. Pt, Pd……on xGnPon xGnP

2. 2. PtMPtM alloys on xGnPalloys on xGnP

3. 3. AuAgAuAg on xGnPon xGnP

4. 4. AuMAuM alloys on xGnPalloys on xGnP

5. WC/xGnP Hybrid5. WC/xGnP Hybrid

1. Pseudocapacitors1. Pseudocapacitors

•• Metal oxide/xGnPMetal oxide/xGnP

(RuO2, (RuO2, CuOCuO,,…………))

•• CP/xGnPCP/xGnP

* CP: conducting * CP: conducting

polymerspolymers

2. EDLC2. EDLC

•• Increase surface Increase surface

areaarea

of xGnPof xGnP

•• Oxidation of xGnPOxidation of xGnP

1. Non1. Non‐‐Li BatteryLi Battery

•• conductive conductive

enhancer inenhancer in

cathodecathode

2. Li Battery2. Li Battery

•• AnodeAnode

•• CNF/xGnP CNF/xGnP

compositecomposite

•• Metal oxide/xGnPMetal oxide/xGnP

(MnO2, SnO2, (MnO2, SnO2,

SiO2SiO2…….).)

•• Nano metals/xGnPNano metals/xGnP

1. Direct application1. Direct application

2. Pillared xGnP2. Pillared xGnP

3. M/xGnP (M=Pd, Ni.)3. M/xGnP (M=Pd, Ni.)

Applications of xGnP: Energy Devices*

* combined * combined

with metalswith metals

Fuel Cell Li Ion BatteryHigh performance, inexpensive xGnP-

supported electrocatalysts for hydrogen-oxygen fuel cells

Gas supply &

current collector PEM

PtxGnP

• Reduction of Pt usage• Pt-free catalysts

Nanosized metal oxide coated and surface modified xGnP for anode and

cathode in Li Ion batteries

• Superior long-term stability of anode material and battery recharging performance

separator

nanocompositeanode

Current collector e.g. Al or Cu foil

Current collector

Al foil

Cell housing

+-

cathode

Liquid/polymer electrolyte

Li+

Electrolyte

xGnP anode

Li ionMetal element

HH

HH

H

oxidation

Lithiation

COOLiOLi

OLI

OLi

COOLi

Glass slide coated with xGnP with ~80% Glass slide coated with xGnP with ~80% transmission in visible spectrumtransmission in visible spectrum

0

10

20

30

40

50

60

70

80

90

500 700 900 1100 1300 1500 1700 1900

W avelength (nm)

Tra

nsm

ittan

ce (%

)4 nm

20 nm

10 nm

Monolayer of graphene covering a glass slide. Transmission ~75% from 500 to 2000nm.Conductivity ~1000 S/cm

‘‘xGnPxGnP’’ Exfoliated Graphite NanoExfoliated Graphite Nano­­PlateletsPlatelets

DRZAL xGnP Group

Sanjib BiswasHuang WuXian JiangJinglei Jiang

Anchita MongaHiroyuki Fukushima, PhD

InHwan Do, PhDHwan Man Park, PhD

Wanjun Liu, PhDXiaobing Li, PhD

Award Winner 2007

MSU SpinMSU Spin--off Company:off Company: XG Sciences, XG Sciences, Inc. Michael R. Knox, CEOInc. Michael R. Knox, CEO

ChemicalIndustry

Sensors

Bioproducts

Fuel Cell

Li Battery

Applications of Graphite NanoPlatelets (xGnP) with Nanosized Metals and Metal oxides

Solar Cells

Super-capacitor

H2 Storage

Polymer Multi-

functional Additive

H2 Production