 The world influenced by nanotechnology.  Nanotechnology is the study of very minute objects, where the size of such objects range to as small as one out of a billion meter.  1 nanometer = 1/1,000,000,000 meter  It is also very diverse, and thus, as the word ‘nano’ suggests, it is the technology that allows scientists to control matter on the atomic scale.

 Nano-particles are defined to be small objects that behave as a small unit in terms of transport and properties.  They may or may not exhibit size-related properties that differ significantly from those observed in fine particles or bulk materials.

 Their properties change together with a change in their sizes.  Heating these nanoparticle arrays also introduce instability into the structures, since smaller nanoparticles start to melt first.  E.g.: Using this method, a nanowire 10 times thinner than any wire, which is important in industries where appliances cannot be too big.

 For quality-control:  When objects become very small till it cannot be seen with the naked eye, it is very hard to control it.  The nano-world created thus allows us to see and access these minute objects, and allows us to take control of it.  E.g.: In medicine, virus are usually very small and hard to detect. Only by controlling them through the nano-world can we find ways to fight these viruses.

 For further research:  Nano-particles are also seen to act as a bridge between bulk materials and atomic or molecular structures, generating great scientific interest.  This is because particles have different properties and act differently when its size is 1 micrometer and larger (bulk materials) or 1 nanometer and smaller (atomic structures)

 For manufacturing more applications:  With nano-particles, they can be introduced into a matrix to allow an object to obtain a more accurate set of properties for certain industries  For instance, nano-particles can be introduced to alter the hardness, the electrical or heat insulation of an object.

 Also known as colloidal gold  A suspension of sub-micrometer-sized gold particles in a fluid – usually water  Not gold in colour, unlike what people may think, as its reduced particles can now absorb green light, reflecting only red light and is red in colour  Exhibit magnetism, unlike normal gold, which are not magnetic Aqueous nano-gold

 Loses its inertness when shrunk to around 3nm ~ 5nm, acting as excellent catalysts  If it is any bigger or smaller than that, it would regain its inertness  One such reaction is the conversion of carbon- monoxide (CO) to carbon-dioxide (CO2). Nano-gold catalyzes this reaction at room temperature and with 100-percent efficiency.  This can be applied to firefighting jobs, where they might have to extinguish fires which have incomplete combustions, and the catalysts help to convert the poisonous CO to CO2.

 Interesting discoveries have been made along the way to explain the varying properties that nano-gold has.  However, none of them had been concrete enough, and can only partially explain some of the phenomena.

 The bond-order-length-strength (BOLS) correlation mechanism:  It indicates that the broken bond induced local strain and quantum trapping and the associated densification of charge and energy in the surface skin are responsible for the size-induced behaviour.  Having shorter and stronger bonds in the surface skin lowers the energy levels and increase the elecronegativity of electrons, hence atoms would take in electrons easily.  This helps to explain why nano-gold are such great catalysts.

 Electron Microscopy:  The nano-gold particles can be attached to many traditional biological probes.  These particles can be manipulated and easily differentiated due to its varying properties when their sizes are changed.  Hence, it can be used in electron-microscopes, where very small objects are observed.

 Health and medical applications:  Used as a therapy for rheumatoid arthritis in rats.  Implantation of gold beads near arthritic hip joints in dogs has been found to relieve pain.  Colloidal gold can even be used to target tumours and provide detection in cancer research.

 Allotropes of carbon with a cylindrical nanostructure.  Categorized as a fullerene: They are molecules totally composed of only carbon atoms.  Hence it is insoluble in water and in other organic solvents  About 10,000 times thinner than a human hair, but up to 18cm in length  Possesses high mechanical strength.

 In solar cells:  A carbon nanotube complex can be formed from carbon nanotubes and fullerenes.  The fullerenes would trap the electrons under sunlight.  The nanotubes would help to allow the electrons to flow, producing electricity as a solar cell

 Paper batteries:  Batteries engineered to use a paper-thin sheet of cellulose with aligned carbon nanotubes  The nanotubes acts as electrodes, and allows the devices to conduct electricity.  It provides a long, steady power output compared to a conventional battery, as it functions both as a lithium-ion battery and a supercapacitor.

 Bullet-proof, stab-proof clothings:  With high mechanical strength, it might be able to stop bullets or knife from penetrating the body totally.  However, the bullet’s kinetic energy might still cause broken bones and internal bleeding.  Hence, it is still a work in progress.

 Carbon may have even more applications in other fullerene structures. Nanotubes are only one of the fullerenes that have a tube shape.  Fullerenes also consist of spherical shapes, which are able to store electricity or heat.  In general, they have more unusual properties chemically, physically and biologically, as showed in the nanotubes too.

 Between 1 nm to 100 nm in size  There are many routes to synthesizing silver nanoparticles.  Physical vapour deposition  Ion implantation  The particles grow in the substrate with the bombardment of ions  Wet chemistry  Reduction of a silver salt with a reducing agent with a colloidal stabilizer

 Medical devices:  Surgical instruments  Surgical masks  Wound dressings  Treatment of HIV-1

 Others:  Household appliances  Samsung has created a material called “Silver Nano”, including silver nanoparticles on the surfaces of household appliances.  The cathode in a silver-oxide battery

 Chang Qing, Sun. (2008, June 27). Nanogold chemistry. Retrieved (2010, June 10) from ml ml  Lehigh University (2004, April 29). Nanogold Does Not Glitter, But Its Future Looks Bright. ScienceDaily. Retrieved (2010, June 10) from htm htm  Luna Nanoworks (n.d.). Nanotechnology - carbon nanomaterials. Retrieved (2010, June 16) from spheres.asp spheres.asp

 Nanomaterials. Wikipedia. Retrieved (2010, June 10) from  Colloidal Gold. Wikipedia. Retrieved (2010, June 10) from  Carbon Nanotube. Wikipedia. Retrieved (2010, June 16) from  Silver nanoparticles. Wikipedia. Retrieved (2010, June 16) from