Carbon Naotube Essay

Carbon Nanotubes

Introduction

Carbon nanotubes are long cylinders of carbon. They can be thought of as graphene wrapped into a cylinder. They have a broad range of electronic, thermal, and structural properties, all dependent on the kind of nanotube in use. They are two types of carbon nanotubes: single walled and multiwalled. A single walled carbon nanotube is a cylinder with a diameter of one nm, whose length can reach upwards of 1000x that. A multiwalled carbon nanotube is essentially a cylinder inside of a cylinder.

Single Walled Carbon Nanotubes The properties of carbon nanotubes are dependent on the composition. A single carbon nanotube has a diameter of one nanometer and can be formed in three different manners. Think of these manners as folding a sheet of a paper from a corner and another from the

Carbon nanotubes are the strongest and stiffest material based on tensile strength and elastic modulus, surpassing Kevlar and steel. When tested, a carbon nanotube had a tensile strength of 63 GPa (4). Another test in 2008 had the strength at 100 GPa (5). The atomic structure of carbon nanotubes allows for minimal collisions between conduction electrons and atoms thus allowing carbon nanotubes to be highly conductive. The strong Sp2 bonds allow carbon nanotubes to withstand higher electric currents compared to copper (Scoville). These same atomic bonds allow carbon nanotubes to withstand high temperatures making them good thermal conductors. Compared to copper, carbon nanofibers can transmit up to 15x the number of watts per kelvin mass. Though this number varies depending on the temperature of the carbon nanofibers.

Characterization

Carbon nanotubes can be formed through three different methods: arc discharge, laser ablation, and chemical vapor deposition. Each method has their own advantages and disadvantages. All methods involve the use of heating in one way or another.

Arc