ARTICLE pubs.acs.org/jchemeduc
Chemistry of Carbon Nanotubes for Everyone Sharmistha Basu-Dutt,*,† Marilyn L. Minus,‡ Rahul Jain,§ Dhriti Nepal,§ and Satish Kumar§ †
Department of Chemistry, University of West Georgia, Carrollton, Georgia 30118, United States Department of Mechanical and Industrial Engineering, Northeastern University, Boston, Massachusetts 02115, United States § School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0295, United States ‡
ABSTRACT: Carbon nanotubes (CNTs) have the extraordinary potential to change our lives by improving existing products and enabling new ones. Current and future research and industrial workforce professionals are very likely to encounter some aspects of nanotechnology including CNT science and technology in their education or profession. The simple structure and interesting chemistry of CNTs make their inclusion in an undergraduate curriculum appropriate. An overview of the chemistry of CNTs is presented starting with a brief history followed by discussions on chemical structure, exceptional properties, potential applications, nature of technological challenges, and possible solutions that will expand the optimal utilization of these materials in the near future. This article is intended to be a starting point for developing a variety of CNT-based undergraduate projects. KEYWORDS: General Public, Upper-Division Undergraduate, Analytical Chemistry, Interdisciplinary/Multidisciplinary, Organic Chemistry, Physical Chemistry, Textbooks/Reference Books, Applications of Chemistry, Consumer Chemistry, Nanotechnology
ver the past decade, the term “nano” has found a prominent place in a variety of professional and popular media. There are many different opinions about where this new and fast evolving global cross-disciplinary undertaking will lead us, but many would agree that it has the extraordinary potential to change our lives by improving existing technologies to enable new product development. The ability to fabricate, characterize, and utilize material structures on the 1100 nm scale will profoundly influence future research and developments in physics, chemistry, and biology; as well as revolutionize bio-, computer, mechanical, and electrical engineering; electronics and communications; medicine; transportation; and space exploration by making new materials, sensors, and devices. The field of nanotechnology is very broad and understanding every aspect of it, for an individual, is impossible. Yet, the far-reaching nature of this field makes it vital for everyone to understand some aspects that are most relevant to their professional and personal lives. According to the U.S. National Nanotechnology Initiative (NNI), “nanoscience involves research to discover new behaviors and properties of materials with dimensions at the nanoscale, which ranges roughly from 1 to 100 nanometers” and “nanotechnology is the way discoveries made at the nanoscale are put to work.”1 The nanoscale vision can be attributed to Nobel Laureate Richard Feynman who gave a lecture in 1959 entitled “There is Plenty of Room at the Bottom—An Invitation to Enter a New Field of Physics”, and encouraged manufacturing of objects that can be maneuvered at the level of an individual atom.2 Problems encountered today in processing nanomaterials were well predicted by Professor Feynman. For example, he had stated, “There is a problem that materials stick together by the molecular (Van der Waals) attractions. It would be like this: After
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Copyright r 2011 American Chemical Society and Division of Chemical Education, Inc.
you have made a part and you unscrew the nut from a bolt, it isn’t going to fall down because the gravity isn’t appreciable; it would be even hard to get it off the bolt.” In the light of this remark about nanoscale aggregation (sticking) phenomena, it is easy to understand the problems of dispersing nanomaterials into a given media. He also stated that, “The problems of Chemistry and Biology can be greatly helped if our ability to see what we are doing, and to do things on an atomic level, is ultimately developed a development which I think cannot be avoided.” The development of scanning tunneling and atomic force microscopes in 1980s has provided us with the initial ability for such studies, and since then, many other instrumental developments have aided nanoscale (atomic level) studies. In addition, the first books on nanotechnology were written by Eric Drexler even though some of the views are perhaps controversial.3 Nanomaterials such as thin films and engineered surfaces, where one of the dimensions (i.e., thickness) is on the order of the nanometer scale, have been used for decades in silicon integrated circuits, fuel cells, and catalysts. New research has now led to the development of two- and three-dimensional nanomaterials, where one or more dimensions are at the nanometer scale. Carbon and inorganic nanotubes and nanowires can therefore be considered as examples of two- or three-dimensional nanomaterials. Nanoparticles, dendrimers, and quantum dots with all three dimensions at the nanometer scale display many intriguing phenomena observable at this scale, but they are unobservable in the bulk material. For example, copper nanoparticles do not exhibit the same malleability and ductility as bulk copper,4 and even though Published: October 27, 2011 221
dx.doi.org/10.1021/ed1005163 | J. Chem. Educ. 2012, 89, 221–229
Journal of Chemical Education
ARTICLE
Table 1. Enhancement of Surface-to-Volume Ratio (SVR) at the Nanoscale Compared to the Meterscale Cube
Surface Area/nm2
Volume/nm3
SVR/ (nm2/nm3)
SVR Enhancement
1 m3
6 1018 (= 6 m2)
1 1027 (= 1 m3)
6 109 nm2/nm3
6/(6 109) = 109
1 nm
3
6
2
1
6 nm /nm
Table 2. Carbon NanotubeRelated Publications, 19912008 Year
Table 3. Worldwide Distribution of Carbon Nanotube Publications, 19912008
No. of publications
19912000
3000
20012008
34719
3
Country United States
No. of Publications
Country
No. of Publications
11,400
India
870
China
8,900
Spain
839
4,900 2,400
Canada Singapore
761 656 648
2001
1395
Japan Germany
2002
2161
Korea
2,400
Australia
2003
2741
France
1,790
Switzerland
548
2004
3762
United Kingdom
1,724
Belgium
536
2005
4597
Russia
1,196
Brazil
488
2006
5645
Taiwan
1,143
Israel
466
2007
6680
Italy
Poland
423
2008
7738
a bulk sample of gold is yellow, a solution of gold nanoparticles can appear to be a variety of colors depending on the size of the nanoparticles, including red for particles
