Carbon Nanotubes and Graphene

Kazuyoshi Tanaka, S. Iijima

• Publisher: Elsevier
• Year: 2014
• eBook ISBN: 9780080982687
• Edition: 2
• Topic: Physical Sciences
• Subtopic: Physical & Theoretical Chemistry

Carbon Nanotubes and Graphene is a timely second edition of the original Science and Technology of Carbon Nanotubes. Updated to include expanded coverage of the preparation, purification, structural characterization, and common application areas of single- and multi-walled CNT structures, this work compares, contrasts, and, where appropriate, unitizes CNT to graphene. This much expanded second edition reference supports knowledge discovery, production of impactful carbon research, encourages transition between research fields, and aids the formation of emergent applications. New chapters encompass recent developments in the theoretical treatments of electronic and vibrational structures, and magnetic, optical, and electrical solid-state properties, providing a vital base to research. Current and potential applications of both materials, including the prospect for large-scale synthesis of graphene, biological structures, and flexible electronics, are also critically discussed. - Updated discussion of properties, structure, and morphology of biological and flexible electronic applications aids fundamental knowledge discovery - Innovative parallel focus on nanotubes and graphene enables you to learn from the successes and failures of, respectively, mature and emergent partner research disciplines - High-quality figures and tables on physical and mathematical applications expertly summarize key information – essential if you need quick, critically relevant data

Chapter 1

Classification of Carbon

Kazuyoshi Tanaka Department of Molecular Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan

Abstract

A simple classification of carbon material based on the hybridization state and [H]/[C] atomic ratio is summarized. It is noted that π conjugation of carbon materials is rather robust, which appears on the curved surface of fullerene and carbon nanotubes.

Keywords

spⁿ-hybridization

[H]/[C] atomic ratio

graphene

graphite

fullerene

carbon nanotube (CNT)

amorphous carbon (a-C)

carbine

diamond

One of the reasons of fertile chemical nature of carbon materials comes from its hybridization state, which also basically determines the features of the variety of organic compounds. In association with this fact, classification of carbon materials would be of importance, which can be simply seen in terms of a certain domain map as shown in Figure 1.1. In this map there are two axes: one is the degree of spⁿ hybridization with taking n as variable and the other [H]/[C] atomic ratio of the material. Typical carbon materials and the relatives occupying specific points on this domain map are shown in Figure 1.2.

Figure 1.1 Domain map of carbon-material family.

Figure 1.2 Various carbon materials and their relatives: (a) carbyne (polyyne), (b) graphene, (c) diamond, (d) polyethylene, (e) polyacetylene, (f) benzene, (g) polyacene, (h) graphene nanoribbon, (i) nanographene, (j) fullerene and (k) CNT.

Since graphene has complete sp² hybridization at every carbon atom and hydrogen atoms are ideally not involved in the skeleton, it occupies the point (2, 0) on the map, being the same for graphite when neglecting the small interlayer interaction. On the other hand, the point (2, 1) for polyacetylene and benzene has complete sp² hybridization with the [H]/[C] ratio of unity. On the line between the points (2, 1) and (2, 0) exists the graphene-fragments group including graphene nanoribbon and nanographene. Hence, the members belonging to this group also consist of sp² hybridization but their [H]/[C] ratios are between 1 and 0 (mostly between 0.5 and 0) along with the development of carbon skeleton.

Fullerenes and carbon nanotubes (CNTs), moreover, belong to an interesting family without any hydrogen atoms but not have genuine sp² hybridization due to the curved surfaces. In other words, they have the hybridization of sp^{2+ δ}, a bit closer to sp³ (between n = 2 and 3) and, hence, they are on the broken line on the horizontal axis at the right to the point for graphene and graphite. It is, however, generally considered that these two materials are of π conjugation system in actuality. In this sense, π conjugation on the carbon atoms is rather robust even on the curved surface. This feature has been mentioned as σ-bond hybridization due to more mixing of 2s atomic orbital of carbon atom into the original 2pπ orbital [1].

Around the line of the graphene fragments is an ambiguous area surrounded by broken line called amorphous carbon (a-C) including coal, charcoal, coke, soot, carbon black and so on. These members are sometimes of importance in the industrial field and often consist of not only carbon and hydrogen atoms but also heteroatoms, such as oxygen, nitrogen or sulfur. Carbon fibres also belong to this group although they are rather near to graphite from the viewpoints of atomic arrangement. It is of interest to note that the precursor of vapour-grown carbon fibre (VGCF) ...

Table of contents

• Cover
• Title page
• Table of Contents
• Copyright
• List of Contributors
• Preface
• Chapter 1: Classification of Carbon
• Chapter 2: Multidimensional Aspects of Single-Wall Carbon Nanotube Synthesis
• Chapter 3: Differentiation of Carbon Nanotubes with Different Chirality
• Chapter 4: Preparation of Graphene with Large Area
• Chapter 5: Optical Properties of Carbon Nanotubes
• Chapter 6: Phonon Structures and Raman Effect of Carbon Nanotubes and Graphene
• Chapter 7: Transport Properties of Carbon Nanotubes and Graphene
• Chapter 8: Mechanical Properties of Carbon Nanotubes and Graphene
• Chapter 9: Organometallic Chemistry of Carbon Nanotubes and Graphene
• Chapter 10: Preparation and Properties of Carbon Nanopeapods
• Chapter 11: Applications of Carbon Nanotubes and Graphene in Spin Electronics
• Chapter 12: Biological Application of Carbon Nanotubes and Graphene
• Chapter 13: Characteristics and Applications of Carbon Nanotubes with Different Numbers of Walls
• Chapter 14: Graphene Oxide: Some New Insights into an Old Material
• Chapter 15: Graphene Nanoribbon and Nanographene
• Chapter 16: Application of Functional Hybrids Incorporating Carbon Nanotubes or Graphene
• Index