Future Trends For Top Materials

Mário J. F. Calvete

• Publisher: Bentham Science Publishers
• Year: 2016
• Print ISBN: 9781681081250
• eBook ISBN: 9781681081243
• Topic: Technology & Engineering
• Subtopic: Materials Science
• Index: Technology & Engineering

This reference focuses on defined types of compounds which are of interest to readers who are motivated to explore basic information about new materials for advanced industrial applications. General and established synthetic methodologies for several compounds are explained giving a straightforward approaches for researchers who intend to pursue new projects in materials sciences. This book presents 9 chapters, covering phthalocyanines, polymethines, porphyrins, BODIPYs, dendrimers, carbon allotropes, organic frameworks, nanoparticles and future prospects. Each chapter covers detailed synthetic aspects of the most established preparation routes for the specific compounds, while giving a historical perspective, with selective information on actual and outstanding applications of each material, unraveling what likely might be the future for each category. This book is intended as a hands-on reference guide for undergraduates and graduates interested in industrial chemistry and materials science.

Carbon Allotropes as Top Materials

Mário Calvete

Department of Chemistry, Faculty of Science and Technology, University of Coimbra, 3004-535 Coimbra, Portugal

Abstract

Carbon is the basic element of organic materials. Depending on how the carbon atoms are bonded, carbon-based systems can be divided into groups with different physical and chemical properties. As both the widely diamond and graphite carbon allotropes are of natural sources, the main interest here discussed will be regarding the other main existing forms of carbon arising from laboratory practice, which are the fullerenes, carbon nanotubes and graphene. Herein is presented a conspectus on the field of the above mentioned synthetic carbon allotropes, where emphasis is set on their preparation and functionalization methods, along with more detailed examples on several promising applications with 770 references provided. Some synthetic details on the preparation of state-of-the-art compounds are given as well.

Keywords: Capacitors, Carbon allotropes, Carbon nanotubes, Fullerenes, Functionalization of carbon nanotubes, Functionalization of fullerenes, Functionalization of graphene, Graphene, Graphene oxide, Guel cells, Sensors, Solar cells.

INTRODUCTION

Carbon is the basic element of organic materials. The great interest in carbon materials fundamentally originates from a variety of chemical bonding styles, which has never been seen in other elements [1, 2]. Each carbon atom possesses six electrons occupying 1s², 2s², and 2p² atomic orbitals. As a result, a carbon atom may assume three different bonding configurations, sp, sp², and sp³ [3]. Depending on how the carbon atoms are bonded, carbon-based systems can be divided into groups with different physical and chemical properties.

The specific carbon hybridization and its binding to surrounding atoms determine the type of allotrope assumed. sp³ hybridized carbon possesses tetrahedral lattice (diamond), while sp² hybridized carbon may produce buckminsterfullerene, carbon nanotubes or graphite, depending on the conditions in which it is formed. Graphite and diamond are known since primeval times, but it was only in the nineteenth century that the structural difference between diamond and graphite was clarified [4], while buckminsterfullerene and carbon nanotubes have only been discovered within the last twenty years, and are just beginning to be understood. Although the theoretical calculations about graphene properties existed for many decades and graphite thin film has been grown by all types of methods over decades, interest in this material was ignited by two independent reports, published in 2004. de Heer [5] demonstrated that ultrathin epitaxial graphite films grown on SiC with 2D electron gas behavior could be patterned via conventional lithographic techniques.

Each of the graphitic materials possesses different dimensionality (Fig 1). The two-dimensional graphene can be considered as the "mother" of all other dimensionalities, i.e . fullerenes (0-dimension), carbon nanotubes (1-dimension) and graphite (3-dimensions) [6].

Fig. (1))
(a) graphene; (b) graphite; (c) carbon nanotube; (d) fullerene.

As both diamond and graphite carbon allotropes are of natural sources, the main interest here discussed will be regarding the other main existing forms of carbon, which arise from laboratory practice, fullerenes, carbon nanotubes and graphene.

Buckminsterfullerene, C₆₀, was named after Buckminster Fuller, inventor of the geodesic dome), was discovered by Smalley, Kroto and Curl in 1985 [7], being awarded with the Nobel Prize in Chemistry in 1996 for those discoveries [8]. However, C₆₀ has a pre-history. In 1970 Osawa, a Japanese chemist reported about a molecule that would be consisted of 60 carbon atoms [9]. It would be, he guessed, a spherical, stable molecule with soccer ball shape, later discussing its probable theoretical aromatic properties in more detail [10]. Also in theory, Gal’pern and Bochvar published a study in 1973 bringing up these structures [11].

About a decade later, Orville L. Chapman initiated its intents to synthesize C₆₀ [12]. While Chapman and his colleagues were working on attempted syntheses of C₆₀, Smalley and his group were busy with a completely distinct subject, the study of atomic clusters. They used a self-made device in which laser energy was used for vaporization of an element sample, having no interest in carbon until a visitor, Kroto, suggested the use of their device to direct light on some carbon clusters detected by Smalley. When performing the experiment, the researchers observed an atypical concentration of carbon clusters, spontaneously self-assembled from hot nucleating carbon plasma [7].

After this acclaimed disclosure, the unambiguous proof of the soccer ball structure still remained opened. Several ...

Table of contents

• Welcome
• Table of Contents
• Title Page
• BENTHAM SCIENCE PUBLISHERS LTD.
• FOREWORD
• PREFACE
• BIOGRAPHY
• Phthalocyanines as Top Materials
• Polymethines as Top Materials
• Porphyrins as Top Materials
• BODIPY Dyes as Top Materials
• Dendrimers as Top Materials
• Carbon Allotropes as Top Materials
• Organic Frameworks as Top Materials
• Nanoparticles as Top Materials
• Future Prospects