UNIT 3
History of Nanotubes
TEXT A
PART I
“The Discovery”
The discovery of carbon nanotubes stretches back only a decade. Japanese electron microscopist, Sumio Lijima, of the NEC Corporation, a Japanese electronics company, had been studying the atomic-scale structure of carbon fibers for many years. In 1990, researchers reported a method for making large quantities of the carbon molecules called buckminsterfullerene or C60, justifying Lijima's own experiments on carbon stretching back for over a decade.
In 1991 he experimented with the technique that had enabled the C60 researchers to make their new form of carbon. By passing electrical sparks between two closely spaced graphite rods, Lijima's vaporized them and allowed the carbon to condense in a sooty mass. But when he looked at the soot through the microscope, he found something altogether unexpected. Amongst the debris, where others had found C60, were tiny tubes of pure carbon, just a few nanometers across. These 'nanotubes' were hollow but many-layered with tubes inside tubes, like nested Russian dolls and their ends sealed with conical caps.
The electric arc was used by Roger Bacon in the early 1 960s to make "thick" carbon whiskers, and one can speculate that the nanotube discovery was a matter of looking more closely at the smallest products hidden in the soot, Lijima's himself suggests that nanotubes may have been formed in those old experiments, but Bacon lacked the high-power microscope required to see them. Although various fullerenes can be produced by different ways of vaporizing carbon, followed by condensation in tiny clusters, the presence of an electric field in the arc discharge seems to promote the growth of the long tubules. Indeed, the nanotubes form only where the current flows, on the larger negative electrode. The typical rate of deposit is about a millimeter per minute at a current and voltage in the range of 100 amperes and 20 volts respectively, which maintains a high temperature of 2,000-3,000 degrees Celsius.
A year later, quite by chance, Thomas Ebbesen and P. M. Ajayan found a way to produce nanotubes in higher yields and make them available for studies by different techniques. Subsequently they found a way to purify them. An addition of a small amount of transition-metal powder (cobalt, nickel or iron) favors the growth of so-called single-walled nanotubes. The method for mass-producing C60 in 1990 had already electrified physicists and chemists worldwide. C60, a carbon molecule shaped like a soccer ball, was discovered in 1985 by Harry Kroto of the University of Sussex in England. That carbon atoms could combine spontaneously into this complicated structure was astonishing, and the new perspectives that it opened up were acknowledged by the award of the 1996 Nobel prize in chemistry to Smalley, Kroto and colleague Robert Curl. But until 1990, no one could make enough of it to study it properly or do anything useful with it.
I.New words:
fiber – волокно tube – трубка
justify – виправдовувати speculate – роздумувати, робити припущення
researcher – дослідник maintain – підтримувати
tiny – крихітний yield – вихід (продукції)
lack – бракувати to purify – очищати
sooty – чорнувата complicated – ускладнений
Exercises Grammar: The Participle
II.Give Ukrainian equivalents to the following words and word combinations
Decade, electron microscopist, atomic-scale structure, large quantities, technique, carbon, electric are, condensation, by chance, negative electrode, chemistry.
III.Translate the following word-combinations with the Participle I into Ukrainian
a)the plan containing many details; the car developing the speed of 80 km; the student studying foreign languages; the experiment being made at our laboratory; the figures following show; copper wire containing the oxide layers is;
b)achieving good results; using new equipment; while processing the data.
IV.Divide the text into logical parts. Choose the key sentences and translate them
V.Answer the questions
1.When did the researchers reporta method for making large quantity of the carbon molecules?
2.Who used the electric are to make “thick” carbon whishers?
3.Where does the nanotubes form?
4.Who found a way to produce nanotubes in higher yields?
5.What did a carbon molecule shape like?