Awsaf Mahmood Lisan
Mayesha Tafannum
Asif Mahmood Abbas
Buckyball
Hello everyone to another edition of ‘Wonders of the Universe’. In the last edition we explored the unknown world of the ‘Food Additives’, this month we will fly our jet to the future world of the scientific technology: nanotechnology.
What is Nanotechnology?
Nanotechnology is a broad term that covers many areas of science, research and technology. In its most basic form, it can be described as working with things that are small. Things so tiny that they can’t be seen with standard microscopes. The same stuff that has always been there, but we just couldn’t see it. The building blocks of nature, atoms and molecules. Nano-technology involves understanding matter at the “nano” scale.
A nanometer is one-billionth of a meter. In comparison, a human hair is about 100,000 nanometers in diameter.
New types of imaging tools, like the atomic force microscope, have allowed scientists to peek into the nano world. A world that before could only be visualized in theory. These tools help scientists validate theories about the way that atoms group together to form molecules of different types and shapes.
“Consider the element carbon at the nanoscale. In nature, when carbon atoms are arranged one way you get a diamond. If they’re put together another way, you get graphite.” – Eleanor Imster, Earth and Sky Radio Series.
The discovery in 1985 of buckminsterfullerene (buckyball), opened a new era for the chemistry of carbon and for novel materials. In 1991 the Japanese scientist Sumio Iijima reported that in the soot produced while he was making fullerenes he had discovered elongated cage-like structures. Other scientists replicated his work and this led to the development of nanotubes and nanotube technology. These closed-cage carbon structures all contain 12 five-member rings and almost any number of six-member rings. They make highly complex shapes- doughnut shapes, corkscrews and cones have been produced.
Applications of nanotechnology
Nanoprob
Chemists have found single-walled nanotubes (SWNTs) and multi-walled nanotubes (MWNTs). Reacting MWNTs with metal oxides produces carbon nanorods, some of which are superconducting (they have zero resistance to the passage of electric currents). Studies of nanotubes show that they are stiffer than other materials. If embedded in polymer resins they could produce composite materials which would have good electrical conductivity along with enormous strength and great lightness. They could find uses in the aircraft, space and car industries.
One idea is to develop nanoprobes which could circulate around the human blood system and identify cancerous cells. Then surgeons could use lasers to heat up these cells and destroy them. It might sound like science fiction today but some scientists believe it is possible.
The transition of nanotechnology research into manufactured products is limited today, but some products moved relatively quickly to the marketplace and already are having significant impact.
Nanoprobs inside the tiniest artery of our body
The “jumbotron lamp,” that lights many of today’s athletic stadiums is a nanotube-based light source. Additional products available today that benefit from the unique properties of nanoscale materials include: bumpers on cars, sunscreens and cosmetics, stain-free clothing and more.
New applications of nanotechnology that are expected in two to five years are:
• Implantable devices that automatically administer drugs and sense drug levels.
• Cancer tagging mechanisms and real time diagnostics for physicians.
• Sensors for airborne chemicals or other toxins.
• Improved solar cells and fuel cells
• Faster, smarter and inexpensive computers.
The power of nanotechnology is in the manipulation of materials at the nanoscale. This enables scientists to alter the properties of materials to make them do new things and to invent materials not found in nature.
Nanoparticles
Nanotechnology in cosmetics
You are probably aware that mixtures of coal dust and air can explode, although lumps of coal do not explode in air. This is because coal dust has a much larger surface area for the combustion reaction to take place than a lump of coal.
Particles called nanoparticles are much smaller than the particles in coal dust, just a few nanometers across. One nanometer (nm) is one billionth of a meter. For comparison, typical carbon-carbon bond lengths, or the spacing between these atoms in a molecule, are in the range 0.12-0.15 nm. The smallest cellular lifefoms, the bacteria of the genus Mycoplasma, are around 200 nm in length.
Materials reduced to the nanoscale can show very different properties compared with what they exhibit on a macroscale. This offers new opportunities for exciting applications, such as:
• Opaque substances become transparent (eg copper)
• Inert materials become catalysts (eg platinum)
• Stable-materials turn combustible (eg gold)
• Insulators become conductors (eg silicon)
Nanotechnology in Cosmetics
Nanoprticles are now being used in cosmetic preparations. The skin provides natural barriers to chemical being absorbed through it. However, if the particles in cosmetics are scaled down to the size of nanoparticles, they become small enough to penetrate the skin. Such particles are smaller than the wavelength of light and therefore too small to see. Very small particles of titanium (IV) oxide are already being used in sunscreens because they disappear completely into the skin, providing an invisible protective layer. Medications called serums are serum are sold which deliver vitamin E into the skin via nanoparticles.
Who will suffer from the risk?
However some toxicologists are alarmed by this trend to deliver cosmetics through the skin. The skin forms a barrier with the function of keeping harmful substances out of the body. If nanoparticles can penetrate the skin, might they end up in the bloodstream and the brain? What damage might they do? Will other, less welcome, substances piggy-back on those particles? And what will happen if a number of different nanoparticles, eg from hand cream, sunscreen and foundation, join together?
Major cosmetics companies state that nanoparticles will not penetrate the skin to reach the bloodstream or circulate around the body. They claim that their chemical compounds will not go further than the first layer, the stratum corneum. The reality is that we do not know what the effects of these preparations are and further research is necessary.
Types of Nanotechnology
There are many different types of Nanotechnology available. In general they can be classified into the following categories: carbon nanotube, optical (or particle-wave based), crystalline, DNA, and quantum. Each of these categories has a significant impact in the study of Nanotechnology. You see, Nanotechnology is not just technology. It is the study of atoms, and the world as we know it. It is the ability to look deep into what and how basic elements are created and how they can be manipulated to benefit mankind.
Collected and compiled from:
Wikipedia,
Future Science,
Edexcel AS Chemistry.
Special thanks to Baidya Sir and Dr. Qazi Saiful Hoq from Uni World Education.