NANOMATERIALS AND ITS POTENTIAL APPLICATIONS

1 International Journal of ChemTech Research CODEN( USA): IJCRGG ISSN : 0974-4290 Vol. 3, , pp 534-538, April-June 2011 NANOMATERIALS and its POTENTIAL ApplicationsK. Arivalagan1*, S. Ravichandran2, K. Rangasamy3 And of Chemistry, Arignar Anna Govt. Arts College,Cheyyar-604 407, of Chemistry, Vel Tech Engineering College, Vel Tech University,Avadi,Chennai 600 062, of Chemistry, College,Tindivanam-604 001, of Chemistry, SaveethaSchool of Engineering, Chennai 602 105 India.* : NANOMATERIALS are defined as engineered materials with a least one dimension in the range of of nano size have been shown to exhibit enhanced or novel properties including reactivity, greater sensingcapability and increased mechanical strength. The nanotechnique offers simple, clean, fast, efficient, and economic forthe synthesis of a variety of organic molecules, have provided the momentum for many chemists to switch fromtraditional method.

2 In the present article an attempt was made to focus on what is NANOMATERIALS , how is it generated andwhat importance may it : NANOMATERIALS -synthesis, properties, term "Nanotechnology" was first definedbyNorio Taniguchiof the Tokyo Science Universityin 1974. Nanotechnology1-3, shortened to "Nanotech",is the study of manipulating matter on an atomic andmolecular scale. Generally nanotechnology deals withstructures sized between 1 to 100 nm and involvesdeveloping materials or devices within that size. Forcomparison, 10 nanometers is 1000 times smaller thanthe diameter of a human hair. Nanotechnology has thecapacity to improve our ability to prevent, detect, andremove environmental contaminants in air, water, andsoil in a cost effective and environmentally friendlymanner. Nanoscience and nanotechnologies arerevolutionizing our understanding of matter and arelikely to have profound implications for all sectors4-6of the economy, including agriculture and food, energyproduction and efficiency, the automotive industry,cosmetics, medical appliances and drugs, householdappliances, computers, and branch of nanoscience and technology is trulymulti-disciplinary and is an emerging technology withfull of promises to have an impact on virtually everyspectrum of civilization including communications,computing, textiles, cosmetics, sports, therapy,automotives, environmental monitoring, fuel cells andenergy devices, water purification, food and beverageindustry, etc.

3 The ability to construct tiny objectsatom- by-atom or molecule- by- molecule forms one ofthe exciting prospects of the research field in nanoscience. It shows great promise for providing us in thenear future with many breakthroughs that will changethe direction of nanotechnology advances in a widerange of Arivalagan et ChemTech ,3(2)535 The application of NANOMATERIALS can behistorically traced back to even before the generation ofmodern science and technology. In 1857,MichaelFaraday published a paper which explained how metalnano particles affect the colour of church windows. In1959,Richard Feynman (awarded Nobel prize inPhysics in 1965) gave a lecture titled There's Plentyof Room at the Bottom , suggesting the possibility ofmanipulating things at atomic level. He speculated onthe possibility and POTENTIAL of nanosized is generally considered to be the foreseeing ofnanotechnology.

4 Many of his speculations12-16 havebecome reality now. However, the real burst ofnanotechnology didn t come until the early 1990s. Inthe past decades, sophisticated instruments forcharacterization and manipulation17-20 such as scanningelectron microscopy (SEM), transmission electronmicroscopy (TEM) and scanning probe microscopy(SPM) became more available for researchers toapproach the nanoworld. In the early 1990sHuffman andKraetschmer, discovered how to synthesize and purifylarge quantities of fullerenes21-26. This opened the doorto their characterization and functionalization byhundreds of investigators in government and industriallaboratories. Shortly after, at a meeting of the MaterialsResearch Society in 1992, described toa spellbound audience his discovery andcharacterization of carbon nanotubes. This event sentthose in attendance and others downwind of hispresentation into their laboratories to reproduce andpush those discoveries forward.

5 Using the same orsimilar tools as those used by Huffman andKratschmer, hundreds of researchers further developedthe field of nanotechnology. No one knows how manyproducts on the market today contain nanoparticles orare manufactured with the help of of NanomaterialsNanomaterials can be synthesised27-31 by any one of thefollowing involves pyrolysis of hydrocarbons such asacetylene at 7000C in the presence of Fe-silica or Fe-graphite catalyst under inert arc methodIt is carried out by applying direct current (60-100 A and 20-25 V) arc between graphite electrodes of10-20 m evaporation methodIt involves vapourisation of graphite containingsmall amount of Co and Ni, by exposing it to laserbeam at 12000C in a quartz tube reactor. An inert gaslike argon is allowed to pass into the reactor to sweepthe evaporated carbon atoms from the furnace to thecopper collector, on which the NANOMATERIALS vapour depositionIt involves decomposition of vapour ofhydrocarbons such as methane, ethylene, acetylene,etc.

6 , at 11000C in presence of catalysts like Ni, Co, Fesuported on of NanomaterialsTwo principal factors cause the properties32-34of NANOMATERIALS to differ significantly from othermaterials: increased relative surface area, and quantumeffects. To understand the effect of particle size onsurface area, consider a silver dollar. The silverdollar contains grams of coin silver, has adiameter of about 40 mm, and has a total surface areaof approximately square centimeters. If the sameamount of coin silver were divided into tiny particles say 1 nanometer in diameter the total surface area ofthose particles would be 11,400 square meters. Whenthe amount of coin silver contained in a silver dollar isrendered into 1 nm particles, the surface area of thoseK. Arivalagan et ChemTech ,3(2)536particles is million times greater than the surfacearea of the silver dollar!a)Electrical propertiesThe electrical properties of NANOMATERIALS vary betweenmetallic to semiconducting materials.

7 It depends on thedia meter of the NANOMATERIALS . The very high electricalconductivity of nanomaterial is due to minimumdefects in the )Thermal conductivityThe thermal conductivity of NANOMATERIALS are veryhigh, is due to the vibration of covalent bonds. Itsthermal conductivity is 10 times greater than the very high thermal conductivity of nanomaterial isalso due to minimum defects in the )Mechanical propertiesNanomaterials are very strong and withstand extremestrain. Most of the materials fracture on bendingbecause of the presence of more defects, butnanomaterials possesss only few defects in of NanomaterialsBelow we list some key APPLICATIONS ofnanomaterials. Most current APPLICATIONS representevolutionary developments of existing technologies: forexample, the reduction in size of electronics ) Sunscreens and CosmeticsThe traditional chemical UV protectionapproach suffers from its poor long-term stability.

8 Asunscreen based on mineral nanoparticles such astitanium dioxide offer several advantages. Titaniumoxide nanoparticles have a comparable UV protectionproperty. Nanosized titanium dioxide and zinc oxideare currently used in some sunscreens, as they absorband reflect ultraviolet (UV) rays and yet are transparentto visible light and so are more appealing to theconsumer. Nanosized iron oxide is present in somelipsticks as a pigment. The use of nanoparticles incosmetics has raised a number of concerns aboutconsumer ) PaintsIncorporating nanoparticles in paints couldimprove their performance, for example by makingthem lighter and giving them different paint coatings ( lightweighting ), used forexample on aircraft, would reduce their weight, whichcould be beneficial to the ) DisplaysThe huge market for large area, highbrightness, flat-panel displays, as used in televisionscreens and computer monitors, is driving thedevelopment of some NANOMATERIALS .

9 Nanocrystallinezinc selenide, zinc sulphide, cadmium sulphide andlead telluride synthesized by sol gel techniques arecandidates for the next generation of ) BatteriesWith the growth in portable electronicequipment (mobile phones, laptop computers, remotesensors), there is great demand for lightweight, high-energy density batteries. Nanocrystalline materialssynthesized by sol gel techniques are candidates forseparator plates in batteries because of their foam-like(aerogel) structure, which can hold considerably moreenergy than conventional ones. Nickel metal hydridebatteries made of nanocrystalline nickel and metalhydrides are envisioned to require less frequentrecharging and to last longer because of their largesurface ) CatalysisIn general, nanoparticles have a high surfacearea, and hence provide higher catalytic is important for the production of serve as an efficient catalyst for somechemical reaction, due to the extremely large surface tovolume ratio.

10 Platinum nanoparticles are now beingconsidered in the next generation of automotivecatalytic converters because the very high surface areaof nanoparticles could reduce the amount of platinumrequired. Some chemical reactions are also carried outusing NANOMATERIALS . For example, reduction of nickeloxide to the base metal ) MedicineNanotechnology has been a boon in medicalfield by delivering drugs to specific cells usingnanoparticles. The overall drug consumption and sideeffects can be lowered significantly by depositing theactive agent in the morbid region only and in no higherdose than needed. This highly selective approachreduces costs and human suffering. Nanotechnologycan also help to reproduce or to repair damaged tissue. Tissue engineering might replace today'sconventional treatments like organ transplants orartificial implants.