Materials CNT

History• 1991 Discovery of multi-wall carbon nanotubes• 1992 Conductivity of carbon nanotubes• 1993 Structural rigidity of carbon nanotubes• 1993 Synthesis of single-wall nanotubes• 1995 Nanotubes as field emitters• 1996 Ropes of single-wall nanotubes• 1997 Quantum conductance of carbon nanotubes• 1997 Hydrogen storage in nanotubes• 1998 Chemical Vapor Deposition synthesis of aligned

nanotube films• 1998 Synthesis of nanotube peapods• 2000 Thermal conductivity of nanotubes• 2000 Macroscopically aligned nanotubes • 2001 Integration of carbon nanotubes for logic circuits• 2001 Intrinsic superconductivity of carbon nanotubes

Potential Applications

• Tips for Atomic Force Microscopy• Cells for hydrogen storage• Nanotransistors• Electrodes for electromechemical applications• Sensors of biological molecules• Catalysts• Reinforcement of composite materials• Semiconductor or metallic conductive

nanomaterials• Various aerospace applications


• Reinforcement within a polymeric matrix• Outstanding mechanical properties

– High Young’s modulus– Stiffness and flexibility– Unique electronic properties– High thermal stability

• The nearly perfect structure of CNTs, their small diameter, and their high surface area and high aspect ratio, provide an amazing inorganic structure with unique properties extremely attractive to reinforcing organic polymers


• Flat Panel Displays– Prototypes have been made by Samsung

• Gas-Discharge Tubes in Telecom Networks• Energy Storage• Electrochemical Intercalation of Carbon

Nanotubes with Lithium– CNTs can be used as the cathode to make a

battery hold 3x as much charge and output 10x as much power

• Nanoprobes and Sensors


• Use as coatings– Antistatic coatings– Flame barrier coatings– Fouling release coatings

• On boats to prevent marine life from adhering to the ship’s bottom


BMC bicycle frame made of nanotube-reinforced resin,

2005 Tour de France. ARKEMA belongs to the network of partners.


Markets

Energy Electronics AutomotiveStuctural

Composites Others

Battery WindSemicon and

Disk DriveITO

replacementElectrostatic

paintingFuel

systems AerospaceSporting goods

Thermal Management

Flame Retardant

CNT Performan

ce Attrib

ute

High electrical conductivity X X X X X X

High thermal conductivity X X X X

High tensile strength X X X X

High elasticity X X X

High absorbency X X X X

High aspect ratio (L/D) X X X X X X X X X X

Low weight X X X X X

Properties

• When small quantities of nanotubes are incorporated into the polymer, the electrical, optical and mechanical properties improve significantly

• CNTs in large amounts form clusters, diminishing their interaction

• The Young’s modulus of the multi-walled carbon nanotubes is 0 9 TPa⋅

Properties

Physical Properties of Carbon NanotubesBelow is a compilation of research results from scientists all over the world.

All values are for Single Wall Carbon Nanotubes (SWNT's) unless otherwise stated. Equilibrium Structure Average Diameter of SWNT's 1.2 -1.4 nmDistance from opposite Carbon Atoms (Line 1) 2.83 ÅAnalogous Carbon Atom Separation (Line 2) 2.456 ÅParallel Carbon Bond Separation (Line 3) 2.45 ÅCarbon Bond Length (Line 4) 1.42 ÅC - C Tight Bonding Overlap Energy ~ 2.5 eVGroup Symmetry (10, 10) C5V

Lattice: Bundles of Ropes of Nanotubes Triangular Lattice

(2D)Lattice Constant 17 ÅLattice Parameter: (10, 10) Armchair 16.78 Å (17, 0) Zigzag 16.52 Å (12, 6) Chiral 16.52 ÅDensity: (10, 10) Armchair 1.33 g/cm3

(17, 0) Zigzag 1.34 g/cm3

(12, 6) Chiral 1.40 g/cm3

Interlayer Spacing: (n, n) Armchair 3.38 Å (n, 0) Zigzag 3.41 Å (2n, n) Chiral 3.39 Å. Optical Properties Fundamental Gap: For (n, m); n-m is divisible by 3 [Metallic] 0 eV

For (n, m); n-m is not divisible by 3 [Semi-Conducting] ~ 0.5 eV

Electrical Transport Conductance Quantization (12.9 k )-1Resistivity 10-4 -cmMaximum Current Density 1013 A/m2

. Thermal Transport Thermal Conductivity ~ 2000 W/m/KPhonon Mean Free Path ~ 100 nmRelaxation Time ~ 10-11 s.

Elastic Behavior Young's Modulus (SWNT) ~ 1 TPaYoung's Modulus (MWNT) 1.28 TPaMaximum Tensile Strength ~ 100 GPa

http://www.pa.msu.edu/~adamsth3/nanotube/opticalproperties.html

http://www.pa.msu.edu/~adamsth3/nanotube/electricaltransport.html

http://www.pa.msu.edu/~adamsth3/nanotube/thermaltransport.html

Mechanical Properties of Engineering Fibers

Fiber Material Specific Density E (TPa) Strength (GPa) Strain at Break (%)Carbon Nanotube 1.3 - 2 1 10-60 10HS Steel 7.8 0.2 4.1 < 10Carbon Fiber - PAN 1.7 - 2 0.2 - 0.6 1.7 - 5 0.3 - 2.4Carbon Fiber - Pitch 2 - 2.2 0.4 - 0.96 2.2 - 3.3 0.27 - 0.6E/S - glass 2.5 0.07 / 0.08 2.4 / 4.5 4.8

Kevlar* 49 1.4 0.13 3.6 - 4.1 2.8Kevlar is a registered trademark of DuPont.

Properties

Table 2. Transport Properties of Conductive Materials

Material Thermal Conductivity (W/m.k) Electrical ConductivityCarbon Nanotubes > 3000 106 - 107Copper 400 6 x 107Carbon Fiber - Pitch 1000 2 - 8.5 x 106Carbon Fiber - PAN 8 - 105 6.5 - 14 x 106

Properties

Properties

Properties• Electrical conductivity:

Carbon nanotubes are conductors or semiconductors, based on coiling helicity. Their conductivity ranges from 1 S/cm to 100 S/cm. This property has been calculated and verified in experiments.

• Thermal conductivity:Carbon nanotubes feature thermal conductivity close to that of diamond (3000 J/K), the best thermal conductor known.

• Mechanical performance:In the hexagon plane, the Young’s modulus for carbon nanotubes has been theoretically evaluated at 1TPa. Together with this outstanding strength, carbon nanotubes boast high flexibility and good plasticity.

• Adsorption:

Nanotubes were first studied with the objective of becoming a means of storing hydrogen for the new fuel cells. Although this application has been gradually discarded, the fact remains that nanotubes have an empty space around the cylinder axis which can constitute a nanotank. The specific surface of nanotubes is approximately 250 m2/g, imparting good adsorption capacity.

Properties

• CNTs have been shown to possess many extraordinary properties such as strength 16X that of stainless steel and with a thermal conductivity five times that of copper.

• aspect ratio (length over diameter) ranges from 1,000 to 1,000,000

• Electrical Resistivity: 10 -4 Ω-cm• Current Density: 107 amps/cm2

• Thermal Conductivity: 3,000 W/mK• Tensile Strength: 30 GPa• Elasticity: 1.28 TPa

Properties

Properties

• Nanotube Research Articles\Overall\nanotube composites.pdf

• Very good article explaining the basics of CNT’s

Properties

Filling CNTs

CNT–Polymer Interfacial Strength

Effects From Size

Additives• Additives can aid in the dispersion of the CNTs

Functionalized CNTs

• Oxidation on the surfaces of these materials are useful moieties in order to bond new reactive chains that improve solubility, processability and compatibility with other materials and, therefore, improve the interfacial interactions of CNs with other substances

• The most important impact has been produced by oxidation methods which, in addition to reducing impurities, cause chemical modifications of CNTs

• The COOH groups generated in the oxidation process are used to attach different molecules useful to improve surface compatibility of CNTs with other materials

Functionalized CNTs

• The COOH groups generated in the oxidation process are used to attach different molecules useful to improve surface compatibility of CNTs with other materials

• Chemical functionalization has reached an important position in the CNT field, as different chemical processes have been developed to diversify CNT properties

• The remarkable properties obtained when f-CNTs are incorporated into polymeric composites represent a promising route to design ideal materials for aerospace related structural applications

• However, the field requires much deeper fundamental research

Functionalized CNTs

• Chemical functionalized CNTs significantly decreased the electrical conductivity of epoxy nanocomposites due to unbalance polarization effect and physical structure defects due to severe condition during acidic treatment process

• Non chemical functionalized CNTs are more suitable for the electrical applications

• Chemical functionalization of CNT is still necessary for increase dispersion quality and strengthens the interfacial bonding strength with polymer matrix, which more important in structural applications

Functionalized CNTs

Functionalized CNTs (Kentera)

Adhesion and reinforcement in carbon nanotube polymer composite

• The interfacial shear stress is found to increase linearly with the applied strain in small strain regime and a lower bound value for the shear strength is found -- 46 MPa at low temperatures. Such value decreases with the increase of temperature. At large strains the interfacial bonds break successively with the shear stress decreasing in a staircase manner.


• The mechanical properties of the composite are found to be largely enhancedover a wide temperature range from 50 to 350 K compared with the bulk polymer, due to the enhanced VDW interactions. The degree of increase in the Young’s modulus is around 200% for the composite in this study, and the difference with that from the continuum medium approximation based Halpin–Tsai formula suggests that interfacial atomic structure is crucial for a nanocomposite.

PMMA

• Relative to pure PMMA, a 32% improvement in tensile modulus and a 28% increase in tensile strength were observed in PMMA-based nanocomposites using 1.0 wt% nanotube filler.

Epoxy• no improvement in mechanical properties was

observed in epoxy-based nanocomposites.• The poorer mechanical performance of the

latter system can be explained by a decrease of the crosslinking density of the epoxy matrix in the nanocomposites, relative to pure epoxy.

Natural Rubber

PVA

• To summarize, MWNTs have been well dispersed in PVA matrix through gum arabic treatment. The PVA/MWNT composite films exhibit good mechanical properties

PBT

• The addition of up to 0.2 wt% MWCNT to PBT induces an increase of the microhardness of about 12%. The H values obtained are much smaller than those derived from the elastic modulus using Struik’s relation. The use of SWCNT does not improve the micromechanical properties

SBR

• The stress value or normally known as tensile strength has been increased to 21.0% for 1 wt% of CNTs up to 70.26% for 10 wt% of CNTs

• The Young’s modulus or modulus of elasticity has been increased to 11.36 for 1 wt% of CNTs up to 193.91% for 10 wt% of CNTs compared to SBR without CNTs.

Microscope Imaging

Materials CNT

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