By B.Gowtham, Civil dept. C.Abdul Hakeem College of Engineering and Technology, Melvisharam.

 Nano = or one billionth in size  Materials with dimensions and tolerances in the range of 100 nm to 0.1 nm  Metals, ceramics, polymeric materials, or composite materials  One nanometer spans 3-5 atoms lined up in a row  Human hair is five orders of magnitude larger than nanomaterials

 Comprised of many different elements such as carbons and metals  Combinations of elements can make up nanomaterial grains such as titanium carbide and zinc sulfide  Allows construction of new materials such as C 60 (Bucky Balls or fullerenes) and nanotubes

 Black crystalline solid, thermally stable up to 400 °C  Very difficult to oxidize  Doped with alkali metals: conductor and superconductor  Fluorescence  Acceptors of electrons and electronic energy

Bucky Ball (C 60 ) C 240 colliding with C 60 at 300 eV (Kinetic energy)

 Arranged in pentagons and hexagons  A one atom thick seperation of two spaces; inside the ball and outside  Highest tensile strength of any known 2D structure or element, including cross-section of diamonds which have the highest tensile strength of all known 3D structures (which is also a formation of carbon atoms)  Also has the highest packing density of all known structures (including diamonds)  Impenetrable to all elements under normal circumstances, even a helium atom with an energy of 5eV (electron Volt)

Switching nanotube-based memory Carbon based nanotubes

single-walled nanotube (SWNT) nm diameter multi-walled nanotube (MWNT) nm diameter

 Superior stiffness and strength to all other materials  Extraordinary electric properties  Reported to be thermally stable in a vacuum up to 2800 degrees Centigrade (and we fret over CPU temps over 50 o C)  Capacity to carry an electric current 1000 times better than copper wires  Twice the thermal conductivity of diamonds  Pressing or stretching nanotubes can change their electrical properties by changing the quantum states of the electrons in the carbon bonds  They are either conducting or semi-conducting depending on the their structure

 Can be used for containers to hold various materials on the nano-scale level  Due to their exceptional electrical properties, nanotubes have a potential for use in everyday electronics such as televisions and computers to more complex uses like aerospace materials and circuits

 Next-generation computer chips  Ultra-high purity materials, enhanced thermal conductivity and longer lasting nanocrystalline materials  Kinetic Energy penetrators (DoD weapon)  Nanocrystalline tungsten heavy alloy to replace radioactive depleted uranium  Better insulation materials  Create foam-like structures called ‘aerogels’ from nanocrystalline materials  Porous and extremely lightweight, can hold up to 100 times their weight

 Improved HDTV and LCD monitors  Nanocrystalline selenide, zinc sulfide, cadmium sulfide, and lead telluride to replace current phosphors  Cheaper and more durable  Harder and more durable cutting materials  Tungsten carbide, tantalum carbide, and titanium carbide  Much more wear-resistant and corrosion-resistant than conventional materials  Reduces time needed to manufacture parts, cheaper manufacturing

 High power magnets  Nanocrystalline yttrium-samarium-cobalt grains possess unusually large surface area compared to traditional magnet materials  Allows for much higher magnetization values  Possibility for quieter submarines, ultra-sensitive analyzing devices, magnetic resonance imaging (MRI) or automobile alternators to name a few  Pollution clean up materials  Engineered to be chemically reactive to carbon monoxide and nitrous oxide  More efficient pollution controls and cleanup

 Greater fuel efficiency for cars  Improved spark plug materials, ‘railplug’  Stronger bio-based plastics  Bio-based plastics made from plant oils lack sufficient structural strength to be useful  Merge nanomaterials such as clays, fibers and tubes with bio-based plastics to enhance strength and durability  Allows for stronger, more environment friendly materials to construct cars, space shuttles and a myriad of other products