Carbon nanotubes Structure

Eva Košťáková

KNT, FT, TUL

2. Lecture

Carbon

Carbon (from Latin: carbo "coal") is the chemical element with

symbol C and atomic number 6.

Carbon is the 15th most abundant element in the Earth's crust,

and the fourth most abundant element in the universe by mass

after hydrogen, helium, and oxygen. It is present in all known

life forms, and in the human body carbon is the second most

abundant element by mass (about 18.5%) after oxygen.

Diamond Graphite

Fulerene C60 Fulerene C250

Amorphous

carbon Carbon

nanotube

There are several allotropes of carbon of which the best

known are graphite, diamond, and amorphous carbon.

Diamond and graphite

Graphite

Fullerens

A fullerene is any molecule composed entirely of carbon, in the

form of a hollow sphere, ellipsoid or tube. Spherical fullerenes are

also called buckyballs, and they resemble the balls used in

football (soccer). Cylindrical ones are called carbon nanotubes or

buckytubes. Fullerenes are similar in structure to graphite, which

is composed of stacked graphene sheets of linked hexagonal

rings; but they may also contain pentagonal (or sometimes

heptagonal) rings.

Richard Buckminster Fullera == Buckminsterfullerene C60

Nobel price in chemistry - 1996

The first fullerene to be discovered, and the family's

namesake, was buckminsterfullerene C60, made in 1985 by

Robert Curl, Harold Kroto and Richard Smalley.

By 1991, it was relatively easy to produce gram-sized samples

of fullerene powder

Kroto, Curl, and Smalley were awarded the 1996 Nobel Prize

in Chemistry for their roles in the discovery of this class of

compounds

Fullerene (Buckyball) colloids, 1,000,000X.

http://www.nature.com/nnano/journal/v1/n2/full/nnano.2006.62.html

The nucleus to nucleus diameter of a

C60 molecule is about 0.71 nm

nano-onions

Cylindrical fullerenes are called carbon

nanotubes or buckytubes.

A large percentage of academic and popular

literature attributes the discovery of hollow,

nanometer-size tubes composed of graphitic carbon

to Sumio Iijima in 1991.

Sumio Iijima (born 1939) is a Japanese physicist,

often cited as the discoverer of carbon nanotubes.

SWNTs (single wall nanotubes)

Diameter of SWNTs

Optimal 1,4nm

Possible 0,4 – 2,5 nm

3. CARBON NANOTUBES, NANOFIBERS AND NANOWIRES 1

Carbon nanotubes - structure

a) Zigzag structure

b) Armchair structure

c) Chiral structure

"zig-zag"

„chiral"

MWNTs (multi wall nanotubes)

TEM microstructure of MWNTs and nanoparticle

c-MWNTs (multi wall nanotubes)

cb-MWNTs (bamboo multi wall nanotubes)

h-MWNTs ( herringboneMWNTs)

hb-MWNTs (bamboo herringbone multi wall nanotubes)

Hetero-nanotubes

X@SWNT or X@MWNT - Hybrid carbon nanotubes

An uncapped single-wall carbon nanotube with

encapsulated buckyballs. This type of tube is

sometimes referred to as a ‘peapod’ carbon nanotube.

This electron micrograph offers a detailed view of silver beads and the eroded layers

of the nanotube.

MWNT

Ag

http://gtresearchnews.gatech.edu/newsrelease/NANOTUBE.html

SWNTs – 70%purity 1g = 300Euro

MWNTs – 90%purity 1kg = 1000Euro

MWNTs – 95%purity 1g = 40 Euro

MWNTs – 95%purity surface modified 1g = 50-65Euro

Carbon nanotubes price

MWNTs orientation

3. CARBON NANOTUBES, NANOFIBERS AND NANOWIRES 32

Carbon nanofibers: no hollow, diameter -

between 50-200nm, length – several

micrometers.

Carbon nanotubes: presence of hollow, -

from 1nm to several tens of micrometers (It

depends on number of walls), length – several

micrometers.

Nanowires: presence of hollow, - Not from

CARBON, from 1nm to several tens of

micrometers (It depends on number of walls),

length – several micrometers.