Post on 24-Feb-2019
Carbon Nanotubes: Synthesis and Functionalization
L. ValentiniL. Valentini
Materials Engineering Centre, INSTM, UdR Perugia Materials Engineering Centre, INSTM, UdR Perugia -- UniversitUniversitààdi Perugia, di Perugia,
Loc. PentimaLoc. Pentima Bassa Bassa -- TerniTerniWebsite: Website: http://www.unipg.it/materialshttp://www.unipg.it/materials
NanoTech Lab @ TERNISurfaces, Thin films & Nanostructures
STNSTN
Dr.ssa Ilaria Armentano
Dr. Francesco Mengoni
Dr.ssa Federica Meloni
Prof. J. M. Kenny
Dr. Luca Valentini
Unique Properties of Carbon NanotubesUnique Properties of Carbon Nanotubes
Graphene sheet SWNT
• Size: Nanostructures with dimensions of ~1 nm diameter (~20 atoms around the cylinder)
• Electronic Properties: Can be either metallic or semiconducting depending on the diameter or orientation of the hexagons
• Mechanical: Very high strength and modulus. Good properties on compression and extension
• Heat pipe and electromagnetic pipe• Single nanotube spectroscopy yields structure• Many applications are being attempted worldwide
Applications for NanotubesApplications for NanotubesScanning tips and ElectronicsScanning tips and Electronics
S.J. Tans et al. Nature, 393, 49 (1998)
Field Emitter
TransistorSTM/AFM tipsSTM/AFM tipsDirect Analysis of DNADirect Analysis of DNASemiconductor devicesSemiconductor devicesField EmittersField Emitters
New Materials
Fullerene C60 inside nanotubes
Imaging biological molecules
AFM image of Immunoglobulin G resolved by nanotube tips
Challenges for Carbon Nanotube Research
• Control synthesis process to produce tubes with same diameter and chirality
• Until control of synthesis process is achieved, develop effective separation methods:
metallic from semiconductingby diameterby chirality
• Develop method for large-scale, cheap synthesis• Improve nanotube characterization and
manipulation • Develop commercial scale applications
Defects in CNTsDefects in CNTs1Point defects such as Point defects such as
vacanciesvacanciesTopological defects caused Topological defects caused by forming pentagons and by forming pentagons and heptagons e.g. 5heptagons e.g. 5--77--77--5 5 defectdefectHybridization defects Hybridization defects caused due to caused due to functionalization
Ibridizzazione sp31
functionalization
10 nm
1Ref: S Namilae et. al. (2001)
Defects in CNTsDefects in CNTs
1200 1400 1600 1800
SWNTs
Inte
nsity
[arb
. uni
ts]
Wavenumber [cm-1]
F. Mercuri et al., J. Phys. Chem. B (submitted)
Role of Interfaces in CompositesRole of Interfaces in Composites
Critical issues in nanotube compositesCritical issues in nanotube composites–– DispersionDispersion
Load transfer effected by interface characteristicsLoad transfer effected by interface characteristicsInterfaces further affect electrical propertiesInterfaces further affect electrical propertiesInterface Interface Bounding surface with physical / Bounding surface with physical / chemical / mechanical discontinuitychemical / mechanical discontinuity–– Strengthening of interfaces in conventional Strengthening of interfaces in conventional
compositescompositesChemical reactionChemical reactionSurface asperities on fiberSurface asperities on fiber
In CNT composites In CNT composites chemical attachmentschemical attachments
Experimental approach: Plasma TreatmentElectric Fields
π stacking• Techniques
TGAFT-IR (KBr)UV-Vis SEMTEM
Functionalization of CNTsFunctionalization of CNTs
Plasma deposition of fluorinated carbon films on single-walled carbon nanotubes
1000 2000 3000 4000
Tran
smitt
ance
[arb
. uni
ts]
Wavenumber (cm-1)
SWNTs
10 nm 5 nm
1000 2000 3000 4000
F-SWNTs
C=CCF
Tras
mitt
ance
[arb
. uni
ts]
Wavenumber [cm-1]
10 nm
5 nm
PECVD Fluorination of SWNTs (TGA)
200 400 600 80030
40
50
60
70
80
90
100
In Air
Res
idua
l Mas
s [%
]
Temperature [°C]
SWNTs F-SWNTs 25°C F-SWNTs 200°C
200 400 600 800
60
70
80
90
100 In Nitrogen
Res
idua
l Mas
s [%
]
Temperature [°C]
F-SWNTs 25°C SWNTs F-SWNTs 200°C
STM
200 400 600 8000
20
40
60
80
100
120
140
160
CF4
COF2
CO2
DTG
[µg/
µgi*m
in]
Temperature [°C]
SWNTs F-SWNTs 25°C F-SWNTs 200°C
F-SWNTsSWNTs
500 1000 1500 2000 2500 3000 3500 4000
NH
NH2
Tras
mitt
ance
[arb
. uni
ts]
Wavenumber [cm-1]
DETA F-SWNTs+DETA
1000 1050 1100 1150 1200 1250
CN Region
Tras
mitt
ance
[arb
. uni
ts]
Wavenumber [cm-1]
DETA F-SWNTs+DETA
Sidewall Functionalization of SWNTsthrough CF4 Plasma Treatment and Subsequent Reaction with Aliphatic
Amines (DETA)
- F +
HF
25°C
RNH-
L. Valentini et al., Chem. Phys. Lett.(accepted)
TGA
500 1000 1500 2000 2500 3000 3500 4000
Tras
mitt
ance
[arb
. uni
ts]
Wavenumber [cm-1]
F-SWNTs/Butilammina
500 1000 1500 2000 2500 3000 3500 4000
Stretching C-H
bending N-H
Stretching C-Nbending N-H
16103370
3290
Tras
mitt
ance
[arb
. uni
ts]
Wavenumber (cm-1)
FTIR
- F +25°C
HF
SWNTs/BuF-SWNTs/Bu
F-SWNTs and Subsequent Reaction with Butylamine
200 400 600 8000.1
1
10
100
Butylamine+F-SWNTs
F-SWNTs
Butylamine
Res
idua
l Mas
s [%
]
Temperature [°C]
- RNH
“An overwhelming Butylamine fraction is
distributed over SWNTssidewalls. These molecules
are chemically attached there.”
Chemical Gating and Photoconductivity of CF4 Plasma Functionalized Single-Walled Carbon Nanotubes by Butylamine
-10 -5 0 5 109,6x10-7
9,6x10-7
-7
9,7x10-7
9,8x10-7
9,8x10-7
F-SWNTs
I sd [A
]
Vg [Volt]
-10 -5 0 5 102,386x10-4
2,388x10-4
2,390x10-4
2,392x10-4
2,394x10-4SWNTs
I sd [A
]
Vg [Volt]
9,7x10 9,0x10I
-10 -5 0 5 108,0x10-10
8,5x10-10
-10
9,5x10-10
1,0x10-9
1,1x10-9
Butylamine+F-SWNTs
sd [A
]
Vg [Volt]
0.0 3.5x103 7.0x103 1.1x104 1.4x104
2.0x10-8
2.2x10-8
2.4x10-8
2.6x10-8
2.8x10-8Butylamine+F-SWNTs
I SD [A
]
Time [s]
L. Valentini et al., J. Appl. Phys. (submitted)
200 400 600 800
0
20
40
60
80
100
0.00
0.02
0.04
0.06
0.08
APTES
T/°C
Templated Assembly of 3-Aminopropyltriethoxysilane at the
Surface of F-SWNTs
- F +
HF 200 400 600 800
0
20
40
60
80
100
-0.01
0.00
0.01
0.02
0.03
0.04
0.05
0.06
T/°C
APTES+SWNTs
200 400 600 80030
40
50
60
70
80
90
100
-0.001
0.000
0.001
0.002
0.003
0.004
0.005
0.006
0.007
F-SWNTs+APTES
T / °C
Selective Functionalization of Metallic Single-Walled Carbon Nanotubes by Conducting Dendrimer (poly(amidoaminepoly(amidoamine)) PAMAM PAMAM
functionalizedfunctionalized withwith naphthalenediimdenaphthalenediimde groupsgroups))
100 120 140 160 180 200
176 (1.43)(18,0)
176 (1.43)(18,0)
165 (1.49)(15,6)
162 (1.53)(14,8)
150.3 (1.65)(12,12)
146,8 (1.69)(19,4)
Inte
nsity
[arb
. uni
ts]
Wavenumber [cm-1]
SWNTs PAMAMC polymer-coated SWNTs
20 nm20 nm
20 nm
FET PAMAMC/SWNTs
-10 -5 0 5 100.0
1.0x10-11
2.0x10-11
3.0x10-11
4.0x10-11
5.0x10-11
6.0x10-11
I sd [A
]
Vg [V]
SWNTs (Lsd
16 µm and W 100 µm)
S.J. Tans et al. Nature, 393, 49 (1998)
-10 -5 0 5 103.2x10-7
3.3x10-7
3.4x10-7
3.5x10-7
3.6x10-7
I sd [A
]
Vg [V]
PAMAMC polymer-coated SWNTs-FET device
-20 -15 -10 -5 0 5 10
4.5x10-5
4.5x10-5
4.5x10-5
4.5x10-5
I sd [A
]
Vg [V]
SWNTs (Lsd 8 µm and W 100 µm)
GrowthGrowth of of selfself--assembledassembled CNTsCNTs bybyPECVDPECVD
Q
Substrato Si
Q + Plasma CH4
CNT
Ni
Pt
Influence of Ni Catalyst LayerNi = 20nmNi = 20nmNi = 5nmNi = 5nmNi = 3nmNi = 3nm
Influence of Pulsed Plasma Mode10-1s10-3s 10-2s
L. Valentini et al., Chem. Phys. Lett. 387 (2004) 356
Electrically Switchable Carbon NanotubeHydrophobic Surfaces
M. Grujicic et al., AppliedSurface Science 206 (2003)
167
R. Pati et al., APL 81 (2002) 2638
500 1000 1500 2000 2500 3000 3500 4000
(d,e)(c)(b)
(a)
Abs
orba
nce
[arb
. uni
ts]
Wavenumber [cm-1]
FTIR spectra obtained under exposure to H2O without (a) an electrical field and at different frequencies (b) 1 Hz, (c) 100 Hz, (d) 1
KHz and (e) 1 MHz (1V ac excitation wave).
The IR spectra obtained at different frequencies under exposure to H2O show that the transparency tends to decrease when increasing the applied frequency. The results obtained suggest that the main contribution to the
interaction between water vapor molecules and the nanotube is associated to adsorbate-dipole/nanotube-dipole interactions.
L. Valentini et al., Diamond and Related Materials 14 (2004) 121.
The NanoChan ProjectThe NanoChan ProjectNano Channel Template: fabrication of a photovoltaic device.
TWO nanotechnologies involved:
1. Nanochannels built in the self-assembled CNTs template with regular and uniform pattern
2. Carbon nanotubes grown by self-assembling on Pt electrodes
Optimize CN properties in order to use themas charge collectors between an activemedium and the readout electronics and study the coupling
Optical Window
R/O electronics
Basic idea
NanotubeNanotube arrayarray
NanoNano--heterohetero--junctionsjunctions
Si
Ligth
Channels for charges
transportation
n-type a-C:H(F) nanochannel
p-type CNTs array
Plasma CF4
Substrate Si
-3 -2 -1 0 1 2 31E-101E-91E-81E-71E-61E-51E-41E-3
a-C:H:F/CNTsCur
rent
[A/c
m2 ]
Voltage [V]
CONCLUDING REMARKSCONCLUDING REMARKS
☺ Research on nanotubes and nanowires show much interesting science with potential for applications☺ Attaching chemical groups to the sidewall of CNTs to modify the properties as needed for applications
Chemical modification of the sidewall may improve the adhesion characteristics of CNTs in a host matrix to make compositesChemical or photosensors
☺ Fluorination of SWNTs with CF4 gas has been shown to attach F covalently to the sidewall☺ Cold plasma approach to functionalization
BUT
Major challenges still exist:- Low material cost, - High durability,- Control of materials properties,- Self-assembly of large numbers of components.
SEM - TEM, Raman, Synthesis of PAMAMProf. S. Russo (Dip. di Chimica e Chimica Industriale, Università di Genova)Dr. Laura Ricco (Dip. di Chimica e Chimica Industriale, Università di Genova)Dr. Jenny Alongi (Dip. di Chimica e Chimica Industriale, Università di Genova)Dr. A. Mariani (Dip. Di Chimica, Universitàdi Sassari)
AcknowledgmentsTGA - FTIRDr. D. Puglia (Dip. di Dip. di Ingegneria Ingegneria CivileCivile e e AmbientaleAmbientale, , Università di PerugiaUniversità di Perugia)Dr. I. Armentano (Dip. di Dip. di Ingegneria Ingegneria CivileCivile e e AmbientaleAmbientale, , Università di PerugiaUniversità di Perugia)Dr. J. Macan (Sveuciliste u Zagrebu)
Funding:Ministry of Education, University and Research through the PRIN, FIRB projectsThe National Consortium of Materials Science and Technology (INSTM)
e-BEAM LithographyDr. G. Pennelli (Dip. di Ingegneria dell' Informazione: elettronica, informatica, telecomunicazioni, Università di Pisa)
Molecular DynamicProf. A. Sgamellotti (Dip. di Chimica, ISTM – CNR, Università di Perugia)Dr. F. Mercuri (Dip. di Chimica, ISTM –CNR, Università di Perugia)