
A nanoflower, in chemistry, refers to a compound of certain elements that results in formations which in microscopic view resemble flowers or, in some cases, trees that are called nanobouquets or nanotrees. These formations are nanometers long and thick so they can only be observed using
electron microscopy
An electron microscope is a microscope that uses a beam of electrons as a source of illumination. It uses electron optics that are analogous to the glass lenses of an optical light microscope to control the electron beam, for instance focusing i ...
.
Production
Several ways to produce nanoflowers are known:
* A process similar to the making of a
carbon nanotube
A carbon nanotube (CNT) is a tube made of carbon with a diameter in the nanometre range ( nanoscale). They are one of the allotropes of carbon. Two broad classes of carbon nanotubes are recognized:
* ''Single-walled carbon nanotubes'' (''S ...
using a
hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and Hydrophobe, hydrophobic; their odor is usually fain ...
gas.
* Heating
gallium
Gallium is a chemical element; it has Chemical symbol, symbol Ga and atomic number 31. Discovered by the French chemist Paul-Émile Lecoq de Boisbaudran in 1875,
elemental gallium is a soft, silvery metal at standard temperature and pressure. ...
(Ga) and then flowing
methane
Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The abundance of methane on Earth makes ...
(CH
4) over, under specific pressure and heat. This forms flower-shaped
silicon carbide
Silicon carbide (SiC), also known as carborundum (), is a hard chemical compound containing silicon and carbon. A wide bandgap semiconductor, it occurs in nature as the extremely rare mineral moissanite, but has been mass-produced as a powder a ...
(SiC) structures.
* Heating a
molybdenum dioxide
Molybdenum dioxide is the chemical compound with the formula MoO. It is a violet-colored solid and is a metallic conductor. The mineralogical form of this compound is called tugarinovite, and is only very rarely found.
Structure
It crystallizes ...
(MoO
2)
thin film
A thin film is a layer of materials ranging from fractions of a nanometer ( monolayer) to several micrometers in thickness. The controlled synthesis of materials as thin films (a process referred to as deposition) is a fundamental step in many ...
on a piece of
molybdenum
Molybdenum is a chemical element; it has Symbol (chemistry), symbol Mo (from Neo-Latin ''molybdaenum'') and atomic number 42. The name derived from Ancient Greek ', meaning lead, since its ores were confused with lead ores. Molybdenum minerals hav ...
foil surrounded by
sulfur
Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...
vapour.
Nanomeadow
In
supercapacitor
alt=Supercapacitor, upright=1.5, Schematic illustration of a supercapacitor
upright=1.5, A diagram that shows a hierarchical classification of supercapacitors and capacitors of related types
A supercapacitor (SC), also called an ultracapacitor, ...
s, energy is stored because the electrodes are coated with a porous material that soaks up ions like a sponge, usually
activated carbon
Activated carbon, also called activated charcoal, is a form of carbon commonly used to filter contaminants from water and air, among many other uses. It is processed (activated) to have small, low-volume pores that greatly increase the surface ar ...
. Nanomeadow supercapacitors store ions in
manganese oxide Manganese oxide is any of a variety of manganese oxides and hydroxides.Wells A.F. (1984) ''Structural inorganic chemistry'' 5th edition Oxford Science Publications, . These include
* Manganese(II) oxide, MnO
* Manganese(II,III) oxide, Mn3O4
* Man ...
(MnO), a material with a much greater capacity for ions than activated carbon.
Scientists at Research Institute of Chemical Defence (Beijing, China) and
Peking University
Peking University (PKU) is a Public university, public Types of universities and colleges in China#By designated academic emphasis, university in Haidian, Beijing, China. It is affiliated with and funded by the Ministry of Education of the Peop ...
created a nanomeadow of microscopic structures, fuzzy flowers of MnO each about 100 nanometres across on a field of messy carbon nanotube grass grown on a
tantalum
Tantalum is a chemical element; it has Symbol (chemistry), symbol Ta and atomic number 73. It is named after Tantalus, a figure in Greek mythology. Tantalum is a very hard, ductility, ductile, lustre (mineralogy), lustrous, blue-gray transition ...
metal
foil
Foil may refer to:
Materials
* Foil (metal), a quite thin sheet of metal, usually manufactured with a rolling mill machine
* Metal leaf, a very thin sheet of decorative metal
* Aluminium foil, a type of wrapping for food
* Tin foil, metal foil ma ...
. Nanomeadows perform 10 times better than MnO alone and can store twice as much charge as the carbon-based electrodes in existing ultracapacitors.
See also
*
*
*
*
*
*
*
*
*
Footnotes
References
*Summary of the 2nd E.E.F. (Enosi Ellinon Fysikon, Hellenic Science Society) Conference in Texnopolis Athens, Greece
External links
*
Photo of nanoflower*{{cite web, url=http://neurophilosophy.wordpress.com/2006/09/06/the-nanoflower-breathalyzer/
, title=The ‘nanoflower’ breathalyzer « Neurophilosophy, publisher=neurophilosophy.wordpress.com, accessdate=2008-06-18
Nanoparticles by morphology