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Materials Chapter 3:. Carbon Nanotube Properties. Table of Contents. Introduction Potential Applications Properties Functionalized CNTs Property Data for Specific Themoplastics Micrographs of Carbon Nanotubes. Introduction. Introduction.
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Materials Chapter 3: Carbon Nanotube Properties
Table of Contents • Introduction • Potential Applications • Properties • Functionalized CNTs • Property Data for Specific Themoplastics • Micrographs of Carbon Nanotubes
Introduction • Scientists have been trying to use the phenomenal mechanical properties of multiwalled carbon nanotubes (MWNT) to create high performance nanocomposites, since their discovery in 1991. • The properties of the MWNT’s suggest that significant improvements should be added to the mechanical and other properties of the polymer matrix, which they reinforce.
Introduction • To alter the properties, strength, stiffness, permeability, optical clarity and electrical conductivity of the nanocomposites consistently, two things need to occur: • the MWNT’s need to be dispersed homogeneously throughout the matrix material, and there needs to be good interfacial bonding between the MWNT’s and the polymer matrix material.
Introduction • Strong bonding at the interface is required to transfer the load from the polymer material to the reinforcing MWNT . • This can be achieved if the surface energy of the carbon nanotubes (CNT) exceeds the cohesive energy of the polymer matrix. • Weak interfacial bonding will result in de-lamination giving instant mechanical failure.
Introduction • Weak interfacial bonding is a result of a non-wetting phenomenon between the CNT and polymer matrix, which is caused by the lack of functional groups on the CNT’s.
Introduction • There are two styles of polymer treatments to promote adhesion at the polymer/CNT interface: • wrapping and non-wrapping. • Polymer wrapping means the treating polymer completely envelops the CNT surface.
Introduction • Non-wrapping polymer treatments are where the polymer backbone extends along the length of the CNT without any portion of the polymer treatment covering more than half of the diameter of the CNT. • Non-wrapping polymer treatments contain a rigid backbone, which results in parallel stacking phenomena between the polymer and the CNT.
Introduction • The addition of treatments to the surface of the nanotubes is being researched and is intended to improve dispersion during processing, such as injection molding. • These treatments consist of functionalizing the CNT by attaching polymeric chains to its surface.
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 CNT 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.
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
Potential Applications • 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
Potential Applications • Use as coatings • Antistatic coatings • Flame barrier coatings • Fouling release coatings • On boats to prevent marine life from adhering to the ship’s bottom
Potential Applications BMC bicycle frame made of nanotube-reinforced resin,2005 Tour de France. ARKEMA belongs to the network of partners.
CNT 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.
CNT 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.
CNT 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
CNT Properties • Nanotube Research Articles\Overall\nanotube composites.pdf • Very good article explaining the basics of CNT’s
