nit srinagar

8/3/2019 nit srinagar

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Nanotechnology is theengineering of functional systemsat the molecular scale. Thiscovers both current work and

concepts that are more advancedIn its original sense,'nanotechnology' refers to theprojected ability to construct itemsfrom the bottom up, usingtechniques and tools beingdeveloped today to makecomplete, high performanceproducts

Human hair fragment and anetwork of single-walled

carbon nanotubes


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The impact of nanotechnology extend from its medical,ethical, mental, legal and environmental applications, tofields such as engineering, biology, chemistry, computing,materials science, military applications, and communications

Nanotechnology's environmental

impact can be split into two

aspects : the potential for

nanotechnological innovations

to help improve the environment,and the possibly novel type

of pollution that nanotechnological

materials might cause if

released into the environment.

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With 15,342 atoms, this parallel-shaftspeed reducer gear is one of the

largest nanomechanical devicesever modeled in atomic detail
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Nanopollution is a generic name for all waste generatedby nanodevices or during the nanomaterialsmanufacturing process. This kind of waste may be verydangerous because of its size. It can float in the air andmight easily penetrate animal and plant cells causingunknown effects

Scrinis raises concerns about nano-pollution, and arguesthat it is not currently possible to precisely predict orcontrol the ecological impacts of the release of thesenano-products into the environment.

nanoparticles could have undesirable effects on the

environment. Two areas are relevant here: (1) In free formnanoparticles can be released in the air or water duringproduction (or production accidents) or as waste by-product of production, and ultimately accumulate in thesoil, water or plant life. (2) In fixed form, where they arepart of a manufactured substance or product, they willultimately have to be recycled or disposed of as waste
http://en.wikipedia.org/w/index.php?title=Nanodevice&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Nanodevice&action=edit&redlink=1http://en.wikipedia.org/wiki/Nanomaterialhttp://en.wikipedia.org/w/index.php?title=Nanodevice&action=edit&redlink=1http://en.wikipedia.org/wiki/Nanomaterialhttp://en.wikipedia.org/wiki/Nanomaterialhttp://en.wikipedia.org/w/index.php?title=Nanodevice&action=edit&redlink=1


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It is not known yet whether certain nanoparticles will

constitute a completely new class of non-

biodegradable pollutant.

In case they do, it is not known how such pollutantscould be removed from air or water because mosttraditional filters are not suitable for such tasks (theirpores are too big to catch nanoparticles

Of the US$710 million spent in 2002 by the U.S.government on nanotechnology research, only$500,000 was spent on environmental impactassessments

Concerns have been raised about Silver Nanotechnology used by Samsung in a range ofappliances such as washing machines and airpurifiers
http://en.wikipedia.org/wiki/Samsunghttp://en.wikipedia.org/wiki/Silver_Nanohttp://en.wikipedia.org/wiki/Samsunghttp://en.wikipedia.org/wiki/Samsunghttp://en.wikipedia.org/wiki/Silver_Nano


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To properly assess the health hazards of engineered

nanoparticles the whole life cycle of these particlesneeds to be evaluated, including their fabrication,storage and distribution, application and potentialabuse, and disposal.

The impact on humans or the environment may varyat different stages of the life cycle.

Nanotechnology could potentially have agreat impact on clean energy production


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Research is underway to use nanomaterials forpurposes including moreefficient solar cells, practical fuel cells, and environmentally friendly

batteries

Nanotechnology may also find applications in batteries. Because of therelatively low energy density of conventional batteries the operatingtime is limited and a replacement or recharging is needed, and thehuge number of spent batteries represent a disposal problem

Research is ongoing to use nanowires and other nanostructuredmaterials with the hope of to create cheaper and more efficient solarcells than are possible with conventional planar silicon solar cells. It isbelieved that these Nano electronics-based devices will enable moreefficient solar cells, and would have a great effect on satisfying globalenergy needs

Another example for an environmentally friendly form of energy is theuse of fuel cells powered by hydrogen. Probably the most prominentnanostructured material in fuel cells is the catalyst consisting of carbonsupported noble metal particles with diameters of 1-5 nm. Suitablematerials for hydrogen storage contain a large number of smallnanosized pores.

Nanotechnology could potentially have a great impact on cleanenergy production
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A strong influence of nanochemistry on waste-water treatment, airpurification and energy storage devices is to be expected.

Mechanical or chemical methods can be used for effectivefiltration techniques. One class of filtration techniques is based onthe use of membranes with suitable hole sizes, whereby the liquid ispressed through the membrane.

Nanoporous membranes are suitable for a mechanical filtrationwith extremely small pores smaller than 10 nm (nanofiltration)and may be composed of nanotubes
http://en.wikipedia.org/wiki/Nanotube_membranehttp://en.wikipedia.org/wiki/Nanotube_membranehttp://en.wikipedia.org/wiki/Nanotube_membranehttp://en.wikipedia.org/wiki/Nanotube_membranehttp://en.wikipedia.org/wiki/Nanotube_membranehttp://en.wikipedia.org/wiki/Nanotube_membrane


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Magnetic nanoparticles offer an effective and reliable methodto remove heavy metal contaminants from waste water bymaking use of magnetic separation techniques. Using nanoscaleparticles increases the efficiency to absorb the contaminants

and is comparatively inexpensive compared to traditionalprecipitation and filtration methods.

Some water-treatment devicesincorporating nanotechnologyare already on the market, with

more in development. Low-costnanostructured separationmembranes methods have beenshown to be effective inproducing potable water in arecent study

10Nanomembrane filter


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Increasing the electricity generated by windmills. Epoxy containingcarbon nanotubes is being used to make windmill blades. The resultingblades are stronger and lower weight and therefore the amount ofelectricity generated by each windmill is greater.

Capturing carbon dioxide in power plant exhaust. Researchers aredeveloping nanostructred membranes designed to capture carbondioxide in the exhaust stacks of power plants instead of releasing it intothe air.

Cleaning up organic chemicals polluting groundwater. Researchershave shown that iron nanoparticles can be effective in cleaning uporganic solvents that are polluting groundwater. The iron nanoparticlesdisperse throughout the body of water and decompose the organic

solvent in place. This method can be more effective and costsignificantly less than treatment methods that require the water to bepumped out of the ground.

Clearing volatile organic compounds (VOCs) from air. Researchers havedemonstrated a catalyst that breaks down VOCs at room temperature.The catalyst is composed of porous manganese oxide in which gold

nanoparticles have been embedded.11
http://www.understandingnano.com/nanotube-windmill-blades.htmlhttp://www.understandingnano.com/nanotube-windmill-blades.htmlhttp://www.understandingnano.com/nanotube-windmill-blades.htmlhttp://nanoglowa.com/http://nanoglowa.com/http://ipp.nasa.gov/innovation/innovation131/4-coverstory.htmlhttp://ipp.nasa.gov/innovation/innovation131/4-coverstory.htmlhttp://ipp.nasa.gov/innovation/innovation131/4-coverstory.htmlhttp://ipp.nasa.gov/innovation/innovation131/4-coverstory.htmlhttp://www.understandingnano.com/nanoparticles-gold-voc-air-pollution.htmlhttp://www.understandingnano.com/nanoparticles-gold-voc-air-pollution.htmlhttp://www.understandingnano.com/nanoparticles-gold-voc-air-pollution.htmlhttp://www.understandingnano.com/nanoparticles-gold-voc-air-pollution.htmlhttp://www.understandingnano.com/nanoparticles-gold-voc-air-pollution.htmlhttp://www.understandingnano.com/nanoparticles-gold-voc-air-pollution.htmlhttp://www.understandingnano.com/nanoparticles-gold-voc-air-pollution.htmlhttp://www.understandingnano.com/nanoparticles-gold-voc-air-pollution.htmlhttp://www.understandingnano.com/nanoparticles-gold-voc-air-pollution.htmlhttp://www.understandingnano.com/nanoparticles-gold-voc-air-pollution.htmlhttp://www.understandingnano.com/nanoparticles-gold-voc-air-pollution.htmlhttp://www.understandingnano.com/nanoparticles-gold-voc-air-pollution.htmlhttp://www.understandingnano.com/nanoparticles-gold-voc-air-pollution.htmlhttp://www.understandingnano.com/nanoparticles-gold-voc-air-pollution.htmlhttp://www.understandingnano.com/nanoparticles-gold-voc-air-pollution.htmlhttp://www.understandingnano.com/nanoparticles-gold-voc-air-pollution.htmlhttp://www.understandingnano.com/nanoparticles-gold-voc-air-pollution.htmlhttp://ipp.nasa.gov/innovation/innovation131/4-coverstory.htmlhttp://ipp.nasa.gov/innovation/innovation131/4-coverstory.htmlhttp://ipp.nasa.gov/innovation/innovation131/4-coverstory.htmlhttp://ipp.nasa.gov/innovation/innovation131/4-coverstory.htmlhttp://ipp.nasa.gov/innovation/innovation131/4-coverstory.htmlhttp://ipp.nasa.gov/innovation/innovation131/4-coverstory.htmlhttp://ipp.nasa.gov/innovation/innovation131/4-coverstory.htmlhttp://nanoglowa.com/http://nanoglowa.com/http://nanoglowa.com/http://nanoglowa.com/http://www.understandingnano.com/nanotube-windmill-blades.htmlhttp://www.understandingnano.com/nanotube-windmill-blades.htmlhttp://www.understandingnano.com/nanotube-windmill-blades.html


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