Done by:Chan Medric(3A305)

 Nanotechnology is the study of the nano-world and it is the study of the controlling of matter on the atomic and the molecular scale.  Nanotechnology usually studies samples of structures between 1 to a hundred nanometers

 Creation of new materials/devices  Medicine  Electronics  biomaterials  Energy production

Nanosensors in plastic packaging -Detect gases given off by food when it spoils and the packaging itself changes color to alert you to food gone bad Plastic films packed with silicate nanoparticles -Reduce the flow of oxygen into the package and the leaking of moisture out of the package -Allow food to stay fresher longer.

Nanoparticles of titanium oxide used in sunscreens -Larger white titanium oxide particles has been used in conventional products for decades, but nanoscale titanium oxide is transparent, hence it is used in sunscreens Antimony –Tin oxide in metals and alloys -Nanoparticles of this oxide are incorporated into a coating to provide scratch- resistance and offer transparent protection from ultra-violet rays which are harmful

 Environmental impact of nanomaterials  Effects on global economics  Toxicity  The above cons have sparked off a debate if the regular usage of nanotechnology is feasible

Defined as a small object that behaves as a whole unit in terms of its transport and properties Effectively a bridge between bulk materials and atomic or molecular structures. A bulk material should have constant physical properties regardless of its size, but at the nano-scale size-dependent properties are often observed. Thus, the properties of materials change as their size approaches the nanoscale and as the percentage of atoms at the surface of a material becomes significant

 Copper can be transparent instead of opaque  stable materials such as aluminium turn combustible  Gold turns into a liquid at room temperature  insulators become conductors (silicon).  Hence it can be seen that the nanoworld can change the properties of materials drasticaly

 A material which deserves special mention is nanogold, which exhibits extremely unique properties in the nanostate.  What was once known as a shiny, yellow metal can seem to have different properties altogether when it is tiny enough.

 Particles of gold which are about 10 nanometres across absorb green light, causing them to appear red.  Its melting point also decreases drastically as the size of the particle decreases.

 Further changes the nanogold exhibits is that it ceases to be noble  They can also react as excellent catalysts which also exhibit magnetism.  Some gold particles also changes its molecular structure and it is changed to an icosahedral structure

 The explanation to the drastic changes the gold particles exhibit is that the shorter and stronger bonds in the surface skin not only lower the energy levels of the electrons but also enhance the elecronegativity and hence make the less-coordinated atoms are more eager to gain electrons from the specimens demonstrating the highly regarded catalytic effect as observed.

 Medical Uses 1.Colloidal gold has been successfully used as a therapy for rheumatoid arthritis in rats. 2. Implantation of gold beads near arthritic hip joints in dogs has been found to relieve pain. 3. An in vitro experiment has shown that the combination of microwave radiation and colloidal gold can destroy the beta-amyloid fibrils and plaque which are associated with Alzheimer's disease.  Video: q07Qhttp:// q07Q

Gold nanoparticles are being investigated as carriers for drugs such as Paclitaxel. In cancer research, colloidal gold can be used to target tumors and provide detection using SERS (Surface Enhanced Raman Spectroscopy) in vivo.  These gold particles surrounded with Raman reporters which provide light emission which provide light emission that is over 200 times brighter than quantum dots.

 While frequently described as being 'silver' some are composed of a large percentage of silver oxide due to their large ratio of surface to bulk silver atoms.  There are many different synthetic routes to silver nanoparticles. They can be divided into three broad categories: - physical vapor deposition - ion implantation - wet chemistry.

 There is an effort to incorporate silver nanoparticles into a wide range of medical devices such as:  bone cement,  surgical instruments,  surgical masks,  wound dressings.  treatment of HIV-1.  Samsung has created and marketed a material called Silver Nano, that includes silver nanoparticles on the surfaces of household appliances.  Silver nanoparticles have been used as the cathode in a silver-oxide battery.

  http :// www. scitopics. com / Nanogold _ chemi stry. html http :// www. scitopics. com / Nanogold _ chemi stry. html   www. howstuffworks. com www. howstuffworks. com  004/04/ htm 004/04/ htm