Physics ACE by Sin Ming Da 4S425 The World of Nano. Physics ACE by Sin Ming Da 4S425

What is Nano? Nano, similar to kilo, is a prefix for measurement scales. 1 nanometer is 1 x 10-9 meters. But how small is that?

What is Nano? To match the width of a human hair, it would take eight hundred particles of 100 nanometres each placed side by side!

Source:http://www.understandingnano.com/introduction.html

Nanotechnology Defined as the study and use of structures between 1 nanometre and 100 nanometres in size. But, with particles of such minute size which can’t be seen by the naked eye and the conventional microscope, how do scientists study nanotechnology?

History of Nanotechnology Got started in the early 1980s when the Scanning Tunneling Microscope(STM) was invented, which led to the discovery of carbon nanotubes and fullerenes. http://www.youtube.com/watch?v=fToTFjwUc5M View of Gold atoms under a STM

Development of Nanotechnology As scientists realized about the uses of nanomaterials (which will be discussed later), nanotechnology reached a peak in the 90s and 21st Century. The Atomic Force Microscope(AFM or SFM) was invented shortly after the invention of STM. http://www.youtube.com/watch?v=87BQiFCkf9s

What happens in the Nano World? Nanoparticles are particles that have one dimension that is 100 nanometres or less in size. The properties of many materials change when they become nanoparticles!

Gold which does not glitter? When gold is shrank into nanoparticles, its color changes too!

Why? Nanoparticles have a greater surface area per weight than larger particles, causing them to be more reactive to certain other molecules, and becoming another type of substance.

Uses of Nanomaterials – Carbon Nanotubes One of the most accomplished products discovered in nanotechnology. Due to the presence of strong covalent bonds between the carbon atoms, hey exhibit extraordinary strength and unique electrical properties, and are efficient thermal conductors. Often an important subject in the field of material science.

Uses of Carbon Nanotubes Everyday items like clothes and sports gear to combat jackets and space elevators – Due to its mechanical strength.

Paper Batteries The nanotubes are aligned on a piece of cellulose. The nanotubes act as electrodes, making the storage device conduct electricity. The paper battery integrates all of the battery components in a single structure, making it more energy efficient.

Vessel for Drug Delivery The nanotube’s versatile structure can be used for localized drug delivery in and around the body – useful in treating cancer cells. Nanotubes can be filled with a drug and delivered to specific areas where a chemical trigger can release the drugs from the nanotube. More efficient than chemotherapy.

Solution to Water Pollution Nanoparticles can be used to convert the contaminating chemical through a chemical reaction to make it harmless. Studies have shown that this method can be used successfully to reach contaminates dispersed in underground ponds and at much lower cost than methods which require pumping the water out of the ground for treatment.

Solution to Water Pollution For example, iron nanoparticles can be used to clean up carbon tetrachloride pollution in ground water. Also, nanoparticles can also be used to absorb radioactive particles in ground water.

Nanoelectronics Using MEMS techniques to control an array of probes whose tips have a radius of a few nanometers. These probes are used to write and read data onto a polymer film, with the aim of producing memory chips with a density of one terabyte per square inch or greater.

Nanoelectronics Building transistors from carbon nanotubes to enable minimum transistor dimensions of a few nanometers and developing techniques to manufacture integrated circuits built with nanotube transistors.

Fuel Nanotechnology can address the shortage of fossil fuels such as diesel and gasoline by: Making the production of fuels from low grade raw materials economical. Increasing the mileage of engines. Making the production of fuels from normal raw materials more efficient.

Fuel They do all of these by increasing the effectiveness of catalysts. Catalysts made from nanoparticles have a greater surface area to interact with the reacting chemicals than catalysts made from larger particles. The larger surface area allows more chemicals to interact with the catalyst simultaneously, which makes the catalyst more effective.

Fuel This increased effectiveness can make a process such as the production of diesel fuel from coal more economical, and enable the production of fuel from currently unusable raw materials such as low grade crude oil.

Cosmetics Sunscreens. The traditional chemical UV protection approach suffers from its poor long-term stability. A sunscreen based on mineral nanoparticles such as titanium dioxide offer several advantages. Titanium oxide nanoparticles have a comparable UV protection property as the bulk material, but lose the cosmetically undesirable whitening as the particle size is decreased.

Heavy Industry Aerospace Lighter and stronger materials will be of immense use to aircraft manufacturers, leading to increased performance. Spacecraft will also benefit, where weight is a major factor. Nanotechnology would help to reduce the size of equipment and thereby decrease fuel- consumption required to get it airborne. Hang gliders may be able to halve their weight while increasing their strength and toughness through the use of nanotech materials. Nanotech is lowering the mass of supercapacitors that will increasingly be used to give power to assistive electrical motors for launching hang gliders off flatland to thermal-chasing altitudes.

Construction Nanotechnology has the potential to make construction faster, cheaper, safer, and more varied. Automation of nanotechnology construction can allow for the creation of structures from advanced homes to massive skyscrapers much more quickly and at much lower cost. Refineries Using nanotech applications, refineries producing materials such as steel and aluminium will be able to remove any impurities in the materials they create. Vehicle manufacturers Much like aerospace, lighter and stronger materials will be useful for creating vehicles that are both faster and safer. Combustion engines will also benefit from parts that are more hard-wearing and more heat- resistant.

Implications of Nanotechnology Researchers have discovered that silver nanoparticles used in socks only to reduce foot odour are being released in the wash with possible negative consequences. Silver nanoparticles, which are bacteriostatic, may then destroy beneficial bacteria which are important for breaking down organic matter in waste treatment plants or farms.

Implications of nanotechnology A study at the University of Rochester found that when rats breathed in nanoparticles, the particles settled in the brain and lungs, which led to significant increases in biomarkers for inflammation and stress response. Would that happen to human beings too?

Conclusion However, nanotechnology has proved to be extremely useful, and has a lot of applications.

References http://www.understandingnano.com/nano particles.html http://en.wikipedia.org/wiki/List_of_nanot echnology_applications http://science.howstuffworks.com/nanotec hnology.htm