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Home , Carbon nanotube

u 2010 , 6 2010 - il 5 pr A il 5

Nanotubes Mohammad F. Islam

http://islamgroup.cheme.cmu.ed Department of Chemical Engineering and of Chemical Department Korea-US NanoForumSeoul, Korea 2010, Department of & Engineering of Materials Science Department

Carbon

of Nanotubes 100g PRF - Novel Dispersion and Self-Assembly Funding Agencies NSF: CBET-0708418, DMR-0619424 and DMR-0645596 ACS Sloan Foundation DARPA ) s l a i ater Outline Mil M

t f o S to

on i uct d le Wall Carbon Nanotubes (SWNTs Purification, Dispersions and Their Properties g • ntro Idi Sf Sf Idi I Sin Conclusions • • • • Introduction

- Introduction

Soft Materials - ) SWNT Nanotube ( Single wall Carbon ) C60 MWNT “” Multiwall Carbon Nanotube (

Introduction to Single Wall Carbon Nanotubes SWNTs have extraordinary anisotropic properties

~1 nm 100 nm – 10,000 nm

SWNT Strength (~100x )

Tensile strength ~200 GPa Electrical Conductivity (~) Stiffness ~1 TPa Dekker et al., Nature 386, 474 (1997) Elongation ~30% Salvetat et al., PRL 82, 944 (2000) ~3x Diamond

Incorporate anisotropic properties of SWNTs into composites s. l a i ost mater h

. d length nanotubes. vents an l and n so i clean on i

Challenges , spers di diameter van der Waals attraction: 40 KBT/nm omogeneous Large scale production of Hdiiildhil H Control of Determination of bulk properties and structural behavior. Effective integration into composites. Controlled integration into electronic circuits. • • • • • • , 1362 (2005) 306 Hata et. al., Science Research Experience 2007 Research Experience for Undergraduates

Synthesis of SWNTs ) -1 nm

20 nm

2 Collect O wavenumber (cm nanotubes 2 500 1000 1500 2000 fractionated magnetically H

with

5 0

. .

3.0 25 2 2.0 1.5 10 1 0.5 0.0

sity x 10 x sity n n Inte 5 , 589 (2005) burn

4 air magnet

wet

Nature Materials Nature Standard wet air burn withMild acid reflux H Magnetic gradient fractionation anneal

Fractionated

Purification of SWNTs suspension Purification only Flow in nanotube H (Tesla) nm

LMNT puried and Fractionated and puried LMNT HiPCO Purified and Fractionated and Purified HiPCO 20 nm LMNT Purified LMNT HiPCO Purified -12 -8 -4 0 4 8 12

3 2 1 0

-1 -2 -3 /mg) x 10 x /mg) u u (em M -3 micelle Oil droplets water + water Shake group

d + ea

h c + Surfactants hili rop d y + H d hili h d + Surfactant oil water Hydrophobic tail 0 m 2.50 5.00  2.50 5.00 0 + Na - -2 3 DDBS SO a 2x10 N DDBS 2 months , 269 (2003) 3 -4 100 - 6x10 TX 25 H Nano Letters 12 -4 C Dispersing SWNTs: Our Work SDS 5 days 5 days 3x10 Sodium Dodecyl Benzene Sulfonates (NaDDBS) Time: SWNTs: Surfactant:

Metallic (x5)

ion s Emis s Semiconducting (x10) Gate Voltage (V) 50 40 30 20 10 0

-10 -5 0 5 10

6 5 4 3 2 1 0

t (nA) t Curren Wavelength (nm) Optical Properties , 589 (2005) , 589

4 800 1200 1600

0.5 0.4 0.3 0.2 0.1 0.0

ance b b Absor erties Nature Materials p

Purified and Suspended SWNTs Are Undamaged Electrical Pro ) 3

aterials Density (g/cm Materials K) - (W/m esoporous M

Mesoporous Thermal Conductivity weight - to - light M -light strength

high

Ultra-light structural media Ultra-light structural Radiation detector Thermal insulator Battery electrode

: Ultra- Ultra-light Highly porous materials Very high strength Very high surface-area-to-volume ratio Conductivity (S/cm) Silica N/A ~ 0.003 0.0019 ~ 0.1 Aerogels Aerogels: Ultra type Electrical -1 , 168102 (2004) 10 93 Phys. Rev. Lett. network

Strong network -2  10 

Rigidity Percolation at low -3 10 5 4 3 2 1 0 -1

Network formation 10 10 10 10 10 10 10

) a a (P G' , s s odulu M M ateau Pl , 168102 (2004) 93 , 313 (2006) 6 Phys. Rev. Lett. NanoLetters

Aerogels concentration Increasing CNT

CNT Aerogels CNT gels do not break apart , 661 (2007) 3 19 0.02 g/cm Advanced Materials Density:

Aerogels

CNT Aerogels 1 µm , 661 (2007) 10 µm 19 /g 2 20 nm Advanced Materials osts p Electrical Conductivity up to ~10 S/cm Surface area 1860 m Thermal Conductivity ~0.3 W/m-K el g gp 100g

SWNT Aerogels SWNT Aero 3 g/cm mg

0.02 100g weight on 3 aerogel posts weight

12.8 mg ~8,000x Total aerogel mass: own weight 3 µm Density Supports at least 8 . 08 0 4 . Voltage (V) 04 0 0

Aerogels 0 750 -750 1500 Current (mA) -1500 CNT Aerogels 4 . 04 0 - 8 . 08 0 - 2005 y l arge l 17, 1186, ty i v Vacuum removed i uct d Adv. Mater. conductivity on unaffected by backfilling CdC iil l various substances • composite Improved • • Can be backfilled with

Resin “wicks” into sample

Backfilling with epoxy Fracture - Complete fill Vacuum Epoxy + cross linker Epoxy + cross Epon 828 Resin +EpiKure 3234 Crosslinker Aerogel , 075505 (2002) 89 PRL

Fusing CNT Aerogel , 17 (2008) 3 Nature Nanotech.

Fusing CNT Aerogel

functional

ncrease. i creating

s may l for

a i er t used

be properties

e ma

b u t can

CNT Aerogel electronic e nano

th

f the

irradiation

Fusing CNT Aerogel o on th

reng t effect

localized s

ll Irradiation with moderate doses may increase the conductivity of Spatially localized irradiation can be used for creating functional e overa beneficial Increase the tensile strength of macroscopic nanotube products. the tensile strength of macroscopic nanotube Increase

Is it possible to fuse CNTs in 3D structure? Irradiation gives rise to covalent bonds between the tubes. Th llA beneficial effect t on the electronic properties nanotube networks. th f th t b t i l i electronic nanotube-based devices.  CNT Aerogel

Fused CNT Aerogel CNT Aerogel

Fused CNT Aerogel Defects on CNTs A fused CNT junction A

CNT Aerogel

Fused CNT Aerogel

Voltage (V)

CNT Aerogel HP holder_400V_annealing Outside_hole Outside_carbontape_200V_annealing

Fused CNT Aerogel -5 -4 -3 -2 -1 0 1 2 3 4 5

8 7 6 5 4 3 2 7 1 0

- -8 -1 -2 -3 -4 -5 -6

) J (A/cm J 2 and arge l , ht g li ht strength ra- lt u d ase bd b mechanical e b u tb t increase to ally conducting porous structure – CNT on nano b car points d e Conclusions bl d junction at -assem lf se fused 100g d e t be ca i r b can a fbif td e surface area-to-volume ratioaerogel. electric W CNTs thermal properties. • •