Nanotechnology Applications

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Nanotechnology Applications

Nanotechnologies to be more specific: nanomaterials are already used in numerous

products and industrial applications. Our Nanotechnology Products and Applications

database already provides an overview of how nanomaterials and nanostructuring

applications are used today in industrial and commercial appplications across industries

(please note: This is NOT a consumer products database that you can find elsewhere; so

no antibacterial socks, bathroom cleaners, face creams, or pet products here...).

Our section "Ten things you should know about nanotechnology" provides you with an

excellent first overview of what nanotechnologies are, what they are used for, and what

some of the key issues are. If you want to get a more in-depth view of nanotechnology in

important industry areas, then this section is for you.

Here is a brief overview of some current applications of nanomaterials. Most of them

represent evolutionary developments of existing technologies: for example, the

reduction in size of electronics devices.

Composites

An important use of nanoparticles and nanotubes is in composites, materials that

combine one or more separate components and which are designed to exhibit overall the

best properties of each component. This multi-functionality applies not only to

mechanical properties, but extends to optical, electrical and magnetic ones. Currently,carbon fibres and bundles of multi-walled CNTs are used in polymers to control or

enhance conductivity, with applications such as antistatic packaging. The use of

individual CNTs in composites is a potential long-term application. A particular type of

nanocomposite is where nanoparticles act as fillers in a matrix; for example, carbon

black used as a filler to reinforce car tyres. However, particles of carbon black can range

from tens to hundreds of nanometres in size, so not all carbon black falls within our

definition of nanoparticles.

Clays

Clays containing naturally occurring nanoparticles have long been important as

construction materials and are undergoing continuous improvement. Clay particle based

composites containing plastics and nano-sized flakes of clay are also findingapplications such as use in car bumpers.

Coatings and Surfaces

Coatings with thickness controlled at the nano- or atomic scale have been in routine

production for some time, for example in molecular beam epitaxy or metal oxide

chemical vapor depositionfor optoelectonic devices, or in catalytically active and

chemically functionalized surfaces. Recently developed applications include the self-

cleaning window, which is coated in highly activated titanium dioxide, engineered to be

highly hydrophobic (water repellent) and antibacterial, and coatings based on

nanoparticulate oxides that catalytically destroy chemical agents. Wear and scratch-

resistant hard coatings are significantly improved by nanoscale intermediate layers (ormultilayers)

between the hard outer layer and the substrate material. The intermediate layers give

good bonding and graded matching of elastic and thermal properties, thus improving

adhesion. A range of enhanced textiles, such as breathable, waterproof and

stainresistant fabrics, have been enabled by the improved control of porosity at the

nanoscale and surface roughness in a variety of polymers and inorganics.

Tougher and Harder Cutting Tools

Cutting tools made of nanocrystalline materials, such as tungsten carbide, tantalum

carbide and titanium carbide, are more wear and erosion-resistant, and last longer than

their conventional (large-grained) counterparts. They are finding applications in the drills

used to bore holes in circuit boards.Paints

Incorporating nanoparticles in paints could improve their performance, for example by

making them lighter and giving them different properties. Thinner paint coatings


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(lightweighting), used for example on aircraft, would reduce their weight, which could

be beneficial to the environment. However, the whole life cycle of the aircraft needs to

be considered before overall benefits can be claimed. It may also be possible to

substantially reduce solvent content of paints, with resulting environmental benefits.

New types of foulingresistant marine paint could be developed and are urgently needed

as alternatives to tributyl tin (TBT), now that the ecological impacts of TBT have been

recognised. Anti-fouling surface treatment is also valuable in process applications such

as heat exchange, where it could lead to energy savings. If they can be produced at

sufficiently low cost, fouling-resistant coatings could be used in routine duties such as

piping for domestic and industrial water systems. It remains speculation whether very

effective anti-fouling coatings could reduce the use of biocides, including chlorine. Other

novel, and more long-term, applications for nanoparticles might lie in paints that change

colour in response to change in temperature or chemical environment, or paints that

have reduced infra-red absorptivity and so reduce heat loss.

Concerns about the health and environmental impacts of nanoparticles may require the

need for the durability and abrasion behaviour of nano-engineered paints and coatings to

be addressed, so that abrasion products take the form of coarse or microscopic

agglomerates rather than individual nanoparticles.

LubricantsNanospheres of inorganic materials could be used as lubricants, in essence by acting as

nanosized ball bearings. The controlled shape is claimed to make them more durable

than conventional solid lubricants and wear additives. Whether the increased financial

and resource cost of producing them is offset by the longer service life of lubricants and

parts remains to be investigated. It is also claimed that these nanoparticles reduce

friction between metal surfaces, particularly at high normal loads. If so, they should find

their first applications in high-performance engines and drivers; this could include the

energy sector as well as transport. There is a further claim that this type of lubricant is

effective even if the metal surfaces are not highly smooth. Again, the benefits of reduced

cost and resource input for machining must be compared against production of

nanolubricants. In all these applications, the particles would be dispersed in aconventional liquid lubricant; design of the lubricant system must therefore include

measures to contain and manage waste.

In the following, we are taking a closer look at how nanotechnologies already are

impacting many industrial areas. An excellent staring point is this chart that lists an

impressive array of applications of nanoparticles:

Food Nanotechnology

Nanotechnology has begun to find potential applications in the area of functional food by

engineering biological molecules toward functions very different from those they have in

nature, opening up a whole new area of research and development. Of course, thereseems to be no limit to what food technologists are prepared to do to our food and

nanotechnology will give them a whole new set of tools to go to new extremes. For a

more critical view of food nanotechnology, just take a look at "Nanotechnology food

coming to a fridge near you" or "Are you ready for your nano-engineered wine?

But there are also a lot of positives. Let's take a look at the potentially beneficial effects

nanotechnology-enabled innovations could have on our foods and, subsequently, on our

health.

According to a definition in a recent report ("Nanotechnology in Agriculture and Food";

pdf), food is nanofood when nanoparticles, nanotechnology techniques or tools are used

during cultivation, production, processing, or packaging of the food. It does not mean

atomically modified food or food produced by nanomachines.Here is an overview of what nanotechnology applications are currently being researched,

tested and in some cases already applied in food technology:


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Let's start with where the benefits of this will be needed most: third world countries

where food supply is often limited and the quality of available food leads to nutritional

deficiencies and the quality of drinking water ia a major contributor to disease. In a study

by the University of Toronto Joint Centre for Bioethics from two years ago

("Nanotechnology and the Developing World"; pdf), a panel of international experts

ranked the 10 nanotechnology applications in development worldwide with the greatest

potential to aid the poor. Number two on the list was "agricultural productivity

enhancement", number three was "water treatment and remediation" and number six

was "food processing and storage."

Recent research has begun to address the potential applications of nanotechnology for

functional foods and nutraceuticals by applying the new concepts and engineering

approaches involved in nanomaterials to target the delivery of bioactive compounds and

micronutrients. Nanomaterials allow better encapsulation and release efficiency of the

active food ingredients compared to traditional encapsulating agents, and the

development of nano-emulsions, liposomes, micelles, biopolymer complexes and

cubosomes have led to improved properties for bioactive compounds protection,

controlled delivery systems, food matrix integration, and masking undesired flavors.

Nanotechnology also has the potential to improve food processes that use enzymes toconfer nutrition and health benefits. For example, enzymes are often added to food to

hydrolyze anti-nutritive components and hence increase the bio-availability of essential

nutrients such as minerals and vitamins. To make these enzymes highly active, longlived

and cost-effective, nanomaterials can be used to provide superior enzyme-support

systems due to their large surface-to-volume ratios compared to traditional macroscale

support materials.

Application Status

Processed nanostructured or -textured

food (e.g. less use of fat and emulsifiers,

better taste

A number of nanostructured food

ingredients and additives understood to

be in the R&D pipeline; eg. mayonnaise

Nanocarrier systems for delivery of

nutrients and supplements in the form

of liposomes or biopolymer-based

nanoencapsulated substances

A number are commercially available in

some countries and over the internet

Organic nanosized additives for food,

supplements and animal feed

Materials range from colors,

preservatives, flavorings to supplements

and antimicrobials

Inorganic nanosized additives for food,health food, and animal feed A range of inorganic additives (silver,iron, silica, titanium dioxide, selenium,

platinum, calcium, magnesium) is

available for supplements,

nutraceuticals, and food and feed

applications

Food packaging applications eg. plastic

polymers containing or coated with

nanomaterials for improved mechanical or

functional properties (see for instance:

"Food packaging takes over the role ofquality control")

This area makes up the largest share of

the current/short-term market for

nanotech applications in the food sector

(e.g. plastic polymers with nanoclay as

gas barrier; nanosilver and nanozincoxide for antimicrobial action;

nanotitanium nitride for strength)
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Nanocoatings on food contact surfaces

for barrier or antimicrobial properties

A number of nanomaterial-based

coatings are available for food

preparation surfaces and for coating

food preparation machinery

Surface-functionalized nanomaterials Main uses are currently in food

packaging; possible uses emerging in

animal feed

Nanosized agrochemicals R&D stage

Nanosensors for food labelling (see:

"Edible optical nanotechnology sensor for

food packaging")

R&D stage

Water decontamination Nano iron is already available in

industrial-scale quantities. A number of

companies thought to be using the

technology in developing countries

Animal feed applications Nanosized additives specifically

developed or are under development for

feed include nanomaterials that can bind

and remove toxins or pathogens

Nanotechnology in Energy

Nanotechnologies provide the potential to enhance energy efficiency across all branches

of industry and to economically leverage renewable energy production through new

technological solutions and optimized production technologies. Nanotechnology

innovations could impact each part of the value-added chain in the energy sector:

Energy sources

Nanotechnologies provide essential improvement potentials for the development of both

conventional energy sources (fossil and nuclear fuels) and renewable energy sources like

geothermal energy, sun, wind, water, tides or biomass. Nano-coated, wear resistant drill

probes, for example, allow the optimization of lifespan and efficiency of systems for the

development of oil and natural gas deposits or geothermal energy and thus the saving of

costs. Further examples are high-duty nanomaterials for lighter and more rugged rotor

blades of wind and tidepower plants as well as wear and corrosion protection layers for

mechanically stressed components (bearings, gear boxes, etc.). Nanotechnologies will

play a decisive role in particular in the intensified use of solar energy through

photovoltaic systems. In case of conventional crystalline silicon solar cells, for instance,increases in efficiency are achievable by antireflection layers for higher light yield.

First and foremost, however, it will be the further development of alternative cell types,

such as thin-layer solar cells (among others of silicon or other material systems like

copper/indium/selenium), dye solar cells or polymer solar cells, which will predominantly

profit from nanotechnologies. Polymer solar cells are said to have high potential

especially regarding the supply of portable electronic devices, due to the reasonably-

priced materials and production methods as well as the flexible design. Medium-term

development targets are an efficiency of approx. 10% and a lifespan of several years.

Here, for example, nanotechnologies could contribute to the optimization of the layer

design and the morphology of organic semiconductor mixtures in component structures.

In the long run, the utilization of nanostructures, like quantum dots and wires, couldallow for solar cell efficiencies of over 60%.


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Energy conversionThe conversion of primary energy sources into electricity, heat and kinetic energy

requires utmost efficiency. Efficiency increases, especially in fossil-fired gas and steam

power plants, could help avoid considerable amounts of carbon dioxide emissions.

Higher power plant efficiencies, however, require higher operating temperatures and

thus heat-resistant turbine materials. Improvements are possible, for example, through

nano-scale heat and corrosion protection layers for turbine blades in power plants or

aircraft engines to enhance the efficiency through increased operating temperatures or

the application of lightweight construction materials (e.g. titanium aluminides).

Nano-optimized membranes can extend the scope of possibilities for separation and

climate-neutral storage of carbon dioxide for power generation in coal-fired power plants,

in order to render this important method of power generation environmentally friendlier

in the long run. The energy yield from the conversion of chemical energy through fuel

cells can be stepped up by nano-structured electrodes, catalysts and membranes, which

results in economic application possibilities in automobiles, buildings and the operation

of mobile electronics.

Thermoelectric energy conversion seems to be comparably promising. Nano-structured

semiconductors with optimized boundary layer design contribute to increases in

efficiency that could pave the way for a broad application in the utilization of waste heat,for example in automobiles, or even of human body heat for portable electronics in

textiles.

Energy distributionRegarding the reduction of energy losses in current transmission, hope exists that the

extraordinary electric conductivity of nanomaterials like carbon nanotubes can be

utilized for application in electric cables and power lines. Furthermore, there are

nanotechnological approaches for the optimization of superconductive materials for

lossless current conduction.

In the long run, options are given for wireless energy transport, e.g. through laser,

microwaves or electromagnetic resonance. Future power distribution will require powersystems providing dynamic load and failure management, demand-driven energy supply

with flexible price mechanisms as well as the possibility of feeding through a number of

decentralized renewable energy sources.

Nanotechnologies could contribute decisively to the realization of this vision, inter alia,

through nano-sensory devices and power-electronical components able to cope with the

extremely complex control and monitoring of such grids.

Energy storageThe utilization of nanotechnologies for the enhancement of electrical energy stores like

batteries and super-capacitors turns out to be downright promising. Due to the high cellvoltage and the outstanding energy and power density, the lithium-ion technology is

regarded as the most promising variant of electrical energy storage.

Current materials for chemical hydrogen storage do not meet the demands of the

automotive industry, which requires a hydrogen-storage capacity of up to ten weight

percent.

Various nanomaterials, inter alia based on nanoporous metal-organic compounds,

provide development potentials, which seem to be economically realizable at least with

regard to the operation of fuel cells in portable electronic devices.

Another important field is thermal energy storage. The energy demand in buildings, for

example, may be significantly reduced by using phase change materials such as latent

heat stores. Interesting, from an economic point of view, are also adsorption storesbased on nanoporous materials like zeolites, which could be applied as heat stores in

district heating grids or in industry. The adsorption of water in zeolite allows the

reversible storage and release of heat.


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Energy usageTo achieve sustainable energy supply, and parallel to the optimized development of

available energy sources, it is necessary to improve the efficiency of energy use and to

avoid unnecessary energy consumption. This applies to all branches of industry and

private households. Nanotechnologies provide a multitude of approaches to energy

saving.

Examples are the reduction of fuel consumption in automobiles through lightweight

construction materials on the basis of nanocomposites, the optimization in fuel

combustion through wear-resistant, lighter engine components and nanoparticular fuel

additives or even nanoparticles for optimized tires with low rolling resistance.

Considerable energy savings are realizable through tribological layers for mechanical

components in plants and machines. Building technology also provides great potentials

for energy savings, which could be tapped, for example, by nanoporous thermal

insulation material suitably applicable in the energetic rehabilitation of old buildings.

In general, the control of light and heat flux by nanotechnological components, as for

example switchable glasses, is a promising approach to reducing energy consumption in

buildings.

Graphene Nanotechnology in Energy

Graphene-based nanomaterials have many promising applications in energy-related

areas. Just some recent examples: Graphene improves both energy capacity and charge

rate in rechargeable batteries; activated graphene makes superior supercapacitors for

energy storage; graphene electrodes may lead to a promising approach for making solar

cells that are inexpensive, lightweight and flexible; and multifunctional graphene mats

are promising substrates for catalytic systems.

These examples highlight the four major energy-related areas where graphene will have

an impact: solar cells, supercapacitors, lithium-ion batteries, and catalysis for fuel cells.

An excellent review paper ("Chemical Approaches toward Graphene-Based

Nanomaterials and their Applications in Energy-Related Areas") gives a brief overview ofthe recent research concerning chemical and thermal approaches toward the production

of well-defined graphene-based nanomaterials and their applications in energy-related

areas. The authors note, however, that before graphene-based nanomaterials and

devices find widespread commercial use, two important problems have to be solved: one

is the preparation of graphene-based nanomaterials with well-defined structures, and the

other is the controllable fabrication of these materials into functional devices.

Solar cellsGraphene has great potential to be used for low-cost, flexible, and highly efficient

photovoltaic devices due to its excellent electron-transport properties and extremelyhigh carrier mobility. "Recently, several graphene-based solar cells have been reported,

in which graphene serves as different parts of the cell. One of the reasons for the current

interest in graphene is the great potential for transparent and conductive electrodes in

solar cells. Graphene is an ideal 2D material which can be assembled into film electrodes

with good transparency, high conductivity, and low roughness."

Graphene also has other attractive properties for photovoltaic devices: "For example,

graphene has been incorporated into conjugated polymers to improve the exciton

dissociation and the charge-transport properties of the materials. Additionally, graphene

also has potential to be used as photoactive material, since its bandgap and band-

position can be induced and tuned via chemical functionalization or by controlling the

size of the graphene sheets."


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Lithium-ion batteriesThe energy densities and performances of rechargeable lithium ion batteries which are

used widely in portable electronics such as cell phones, laptop computers, digital

cameras, etc. largely depend on the physical and chemical properties of the electrode

materials. Thus, many research attempts have been made to design novel

nanostructures and to explore new electrode materials in order to achieve higher

capacity and to increase the battery's charge rate, increasingly also employing graphene

in form of nanosheets, paper, and carbon nanotube or fullerene hybrids of graphene

materials should depend highly on the layers. Single- or few-layered graphene, with less

agglomeration, should be expected to exhibit a higher effective surface area and thus

better supercapacitor performance."

CatalysisGraphene has recently received special interest in the field of catalysis because of its

unique two-dimensional structure with its high surface area, special electronic and

ballistic transport properties.

"Various graphene-based nanomaterials, such as functionalized graphenes, doped

graphene, and graphene/metal or metal oxide composites, are emerging and have beeninvestigated as catalysts for electrocatalytic reactions in fuel cells or other traditional

catalytic reactions,"

OutlookMany critical problems are still waiting for efficient solutions, particularly regarding the

precise structural engineering of graphene, which is crucial for both bandgap adjustment

and building-block functionalization. According to them, graphene chemistry is obviously

one of the best choices to solve these problems.

In the meantime, graphene-based materials are emerging as highly attractive materials

for real applications, especially in the area of energy conversion and storage.

"Since the incorporation of graphene with an active second phase, such as carbonnanotubes, conducting polymers and metal oxides, can dramatically enhance the

performance due to the synergistic effects, graphene-based composites are of scientific

and industrial interest and may become competitive materials for energy-related

applications,"

Notwithstanding all the progress that has been made in the recent past, the authors

conclude that the research toward an understanding of the relationship between

graphene-based nanomaterials and improved performance in energy-related applications

is still at its early stage, and dilemmas remain for further studies.

Nanotechnology in SpaceNanotechnology will play an important role in future space missions. Nanosensors,

dramatically improved high-performance materials, or highly efficient propulsion systems

are but a few examples.

Propulsion systemsMost of today's rocket engines rely on chemical propulsion. All current spacecraft use

some form of chemical rocket for launch and most use them for attitude control as well

(the control of the angular position and rotation of the spacecraft, either relative to the

object that it is orbiting, or relative to the celestial sphere). Real rocket scientists though

are actively researching new forms of space propulsion systems.

One heavily researched area is electric propulsion (EP) that includes field emissionelectric propulsion (FEEP), colloid thrusters and other versions of field emission thrusters

(FETs). EP systems significantly reduce the required propellant mass compared to

conventional chemical rockets, allowing to increase the payload capacity or decrease the


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launch mass. EP has been successfully demonstrated as primary propulsion systems for

NASAs Deep Space 1, Japans HAYABUSA, and ESAs SMART-1 missions.

A nanotechnology EP concept proposes to utilize electrostatically charged and

accelerated nanoparticles as propellant. Millions of micron-sized nanoparticle thrusters

would fit on one square centimeter, allowing the fabrication of highly scalable thruster

arrays.

Pretty far out are proposals that the manipulation of Casimir forces could lead to a

propulsion system for interstellar spaceships. The basic idea is that if one could exploit

the fact that vacuum is an energy reservoir, thanks to zero-point energy, future space

travelers would have access to a limitless energy source. The only thing they need, of

course, is some kind of propulsion system that harvests the required energy from the

vacuum. That this is not totally crazy was demonstrated in a 1984 paper. Serious

research efforts are being made in various laboratories to harness the Casimir and

related effects for vacuum energy conversion (read more: "nanotechnology, the

mysterious Casimir Force, and interstellar spaceships").

Radiation shielding

Radiation shielding is an area where nanotechnology could make a major contribution tohuman space flight. NASA says that the risks of exposure to space radiation are the most

significant factor limiting humans ability to participate in long-duration space missions. A

lot of research therefore focuses on developing countermeasures to protect astronauts

from those risks. To meet the needs for radiation protection as well as other

requirements such as low weight and structural stability, spacecraft designers are

looking for materials that help them develop multifunctional spacecraft hulls. Advanced

nanomaterials such as the newly developed, isotopically enriched boron nanotubes could

pave the path to future spacecraft with nanosensor-integrated hulls that provide

effective radiation shielding as well as energy storage.

Another area of required radiation shielding is the protection of onboard electronics. It

has been reported previously that electronic devices became more radiation tolerantwhen their dimensions are reduced. For example, multi-quantum well or quantum dot

devices can be tens or hundreds times more radiation tolerant than conventional bulk

devices. It even was shown that quantum dot/CNT-based photovoltaic devices were five

orders of magnitude more resistant than conventional bulk solar cells.

Recently, a few studies on radiation effects of high energetic particles such as proton,

electron, and

heavy ions on nanomaterials like carbon nanotubes and nanowires have focused on the

changed structural properties of the nanomaterials after irradiation (read more: "Carbon

nanotubes harden electronics for use in aerospace").

Anti-satellite weapon countermeasure

In January 2007, China successfully tested an Anti-satellite (ASAT) missile system by

destroying their own defunct LEO satellite, which generated huge amounts of space

debris. This ASAT test raised worldwide concerns about the vulnerability of satellites and

other space assets and possibility of triggering an arms race in space. In order to meet

emerging challenges posed by such ASAT missile systems, military strategists and

researchers are developing novel technologies to protect their space assets. In view of

this, Raytheon Company has developed a counter measure system using quantum dots

to protect space assets such as satellites from missile attacks. They have developed a

decoy consisting of quantum dots of different sizes and shapes that are engineered to

emit radiation having a radiation profile similar to that of the asset.

Space elevator
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Tie a rock to the end of a piece of ribbon, then spin it over your head. It will be pulled

taut as the rock circles about. Now, imagine a ribbon 62,000 miles long, anchored near

the equator with a weight on the other end. The centrifugal force of the earth's rotation

will make it behave the same way. You'll end up with not only the world's biggest

nunchuck, but also a kind of elevator to outer space.

A space elevator based on carbon nanotube cables is one of those ideas from 1950s-

style futurism that are so whacky they might just work.

Protecting satellites from energy weaponsA recent research paper published at the Center for Strategy and Technology, at the Air

Force's Air War College, discusses how nanotechnology can be used to improve the

design of satellites to mitigate the threats posed by ground-based directed energy

weapons and high-powered microwaves. The paper states that several nations, including

the U.S., Russia and China, already have either built or are developing the technology to

construct ground-based directed energy weapons.

Space instrumentationBlack is black, right? Not so, according to a team of NASA engineers now developing a

blacker-than pitch nanomaterial that will help scientists gather hard-to-obtain scientificmeasurements or observe currently unseen astronomical objects, like Earth-sized planets

in orbit around other stars. The nanomaterial being developed by a team of 10

technologists at the NASA Goddard Space Flight Center in Greenbelt, Md., is a thin

coating of multi-walled carbon nanotubes. While carbon nanotubes would find use in the

Space Elevator thanks to their extraordinary strength, in this application, NASA is

interested in using the technology to help suppress errant light that has a funny way of

ricocheting off instrument components and contaminating measurements.

MIT hosts the Space Nanotechnology Laboratory whose primary mission is to develop

nano-fabrication, advanced lithography and precision engineering technology for building

high performance space instrumentation, including x-ray telescopes and high resolution

x-ray spectrometers, magnetospheric imagers and solar physics instrumentation.

The use of nanotechnology materials and applications in the construction industry should

be considered not only for enhancing material properties and functions but also in the

context of energy conservation. This is a particularly important prospect since a high

percentage of all energy used (e.g., 41% in the United States) is consumed by

commercial buildings and residential houses by applications such as heating, lighting,

and air conditioning.

According to an economic assessment (pdf), nanotechnology has a significant impact in

the construction sector. Several applications have been developed for this specific sectorto improve the durability and enhanced performance of construction components,

energy efficiency and safety of the buildings, facilitating the ease of maintenance and to

provide increased living comfort. Though self-cleaning feature has been possible to

attain using micron sized coatings and surface treatments e.g. Teflon, polysilazane

based coatings, etc. now this feature has become a marketing tool / motto for

nanotechnology applications, especially for consumer markets like construction, textile,

etc.

"Nanoparticles of TiO2, Al2O3 or ZnO are applied as a final coating on construction

ceramics to bring this characteristic to the surfaces. TiO2 is being used for its ability to

break down dirt or pollution when exposed to UV light and then allow it to be washed offby rainwater on surfaces like tiles, glass and sanitaryware. ZnO is used to have UV

resistance in both coatings and paints. Nanosized Al2O3 particles are used to make


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surfaces scratch resistant. These surfaces also prevent / decelerate formation of bad

smells, fungus and mould.

"Basic construction materials cement, concrete and steel will also benefit from

nanotechnology. Addition of nanoparticles will lead to stronger, more durable, self-

healing, air purifying, fire resistant, easy to clean and quick compacting concrete. Some

of the nanoparticles that could be used for these features are nano silica (silica fume),

nanostructured metals, carbon nanotubes (CNTs) and carbon nanofibers (CNFs). Current

pressure to reduce CO2 emissions from the manufacture of cement is guiding research

to use nanotechnology to alter the processing conditions of cement, therefore reducing

these emissions. Concrete structures also make profit from nano-enhanced coatings that

prevent graffiti and other unwanted stains to adhere on to it. In addition to these

materials, new lightweight, flame-retardant, self-healing and resilient construction

materials, e.g. new nanocomposites, are expected to be helped in their development by

nanotechnology.

"Nanotechnology will also have a considerable impact on glass and therefore on

windows. For marketing purposes, these windows are commonly called smart windows

which implies that they are multifunctional through their energy saving, easy cleaning,

UV controlling and photovoltaic features."Nanotechnology could allow the development of materials with better insulation

properties, intelligent structures capable of optimizing the use of energy. New insulating

materials have been developed with the help of advances in nanotechnologies. These

insulating materials are: nanofoams, nanostructured aerogels and vacuum insulated

panels (VIPs).

"In the future, smart living spaces will be made possible via embedded sensing systems

that would enable buildings sense and act according to environment and also to the

users needs."

A review by scientists at Rice University has looked at the benefits of using

nanomaterials in construction materials but also highlights the potentially harmfulaspects of releasing nanomaterials into the environment. The team compiled a list of

current use of nanomaterials in various building applications and also highlighted

potential and promising future uses.

Which nanomaterials are used in constructionCarbon nanotubes Expected benefits are mechanical durability and crack prevention (in

cement); enhanced mechanical and thermal properties (in ceramics); real-time structural

health monitoring (NEMS/MEMS); and effective electron mediation (in solar cells).

Silicon dioxide nanoparticles Expected benefits are reinforcement in mechanical

strength (in concrete); coolant, light transmission, and fire resistance (in ceramics);flame-proofing and anti-reflection (in windows).

Titanium dioxide nanoparticles Expected benefits are rapid hydration, increased degree

of hydration, and self-cleaning (in concrete); superhydrophilicity, anti-fogging, and

fouling-resistance (in windows); non-utility electricity generation (in solar cells).

Iron oxide nanoparticles Expected benefits are increased compressive strength and

abrasion-resistant in concrete.

Copper nanoparticles Expected benefits are weldability, corrosion resistance, and

formability in steel.

Silver nanoparticles Expected benefits are biocidal activity in coatings and paints.

Quantum dots Expected benefits are effective electron mediation in solar cells.

One particular area for nanotechnology in the construction industry is concrete,specifically research on how to reinforce concrete to improve its mechanical

performance.


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Nanotechnology and the EnvironmentNanotechnological products, processes and applications are expected to contribute

significantly to environmental and climate protection by saving raw materials, energy

and water as well as by reducing greenhouse gases and hazardous wastes. Using

nanomaterials therefore promises certain environmental benefits and sustainability

effects. Note, however, that nanotechnology currently plays a rather subordinate role in

environmental protection, whether it be in research or in practical applications.

Environmental engineering companies themselves attach only limited importance to

nanotechnology in their respective fields.

Potential environmental benefitsRising prices for raw materials and energy, coupled with the increasing environmental

awareness of consumers, are responsible for a flood of products on the market that

promise certain advantages for environmental and climate protection. Nanomaterials

exhibit special physical and chemical properties that make them interesting for novel,

environmentally friendly products.

Examples include the increased durability of materials against mechanical stress or

weathering, helping to increase the useful life of a product; nanotechnology-based dirt-

and water-resistant coatings to reduce cleaning efforts; novel insulation materials to

improve the energy efficiency of buildings; adding nanoparticles to a material to reduceweight and save energy during transport. In the chemical industry sector, nanomaterials

are applied based on their special catalytic properties in order to boost energy and

resource efficiency, and nanomaterials can replace environmentally problematic

chemicals in certain fields of application. High hopes are being placed in nano-

technologically optimized products and processes for energy production and storage;

these are currently in the development phase and are slated to contribute significantly to

climate protection and solving our energy problems in the future.

In most commercially available nano-consumer products, environmental protection is

not the primary goal. Neither textiles with nanosilver to combat perspiration odor, nor

especially stable golf clubs with carbon nanotubes, help protect the environment.

Manufacturers often promise such advantages, typically without providing the relevantevidence. Examples include self-cleaning surface coatings or textiles with spot

protection, with are advertized as reducing the cleaning effort and therefore saving

energy, water and cleaning agents.

Emphasis is often placed on the sustainable potential of nanotechnology. Nonetheless,

this usually reflects unsubstantiated expectations. Determining the actual effects of a

product on the environment both positive and negative requires examining the entire

life cycle from production of the raw material to disposal at the end of the life cycle. As a

rule, the descriptions of environmental benefits fail to consider the amount of resources

and energy consumed in producing the products.

Specific examples of nanotechnology applications that benefit theenvironment

Nanotechnology could make battery recycling economically attractive

Many batteries still contain heavy metals such as mercury, lead, cadmium, and nickel,

which can contaminate the environment and pose a potential threat to human health

when batteries are improperly disposed of. Not only do the billions upon billions of

batteries in landfills pose an environmental problem, they also are a complete waste of a

potential and cheap raw material. Researchers have managed to recover pure zinc oxide

nanoparticles from spent Zn-MnO2 batteries alkaline batteries.

Nanomaterials for radioactive waste clean-up in water


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Scientists are working on nanotechnology solution for radioactive waste cleanup,

specifically the use of titanate nanofibers as absorbents for the removal of radioactive

ions from water. Researchers have also reported that the unique structural properties of

titanate nanotubes and nanofibers make them superior materials for removal of

radioactive cesium and iodine ions in water.

Nanotechnology-based solutions for oil spills

Conventional clean-up techniques are not adequate to solve the problem of massive oil

spills. In recent years, nanotechnology has emerged as a potential source of novel

solutions to many of the world's outstanding problems. Although the application of

nanotechnology for oil spill cleanup is still in its nascent stage, it offers great promise for

the future. In the last couple of years, there has been particularly growing interest

worldwide in exploring ways of finding suitable solutions to clean up oil spills through use

of nanomaterials.

Water applications

The potential impact areas for nanotechnology in water applications are divided into

three categories treatment and remediation, sensing and detection, and pollution

prevention (read more: "Nanotechnology and water treatment") and the improvementof desalination technologies is one key area thereof. Nanotechnology-based water

purification devices have the potential to transform the field of desalination, for instance

by using the ion concentration polarization phenomenon (see: "Nanotechnology makes

portable seawater desalination device possible").

Another, relatively new method of purifying

brackish water is capacitive deionization (CDI) technology. The advantages of CDI are

that it has no secondary pollution, is cost-effective and energy efficient. Nanotechnology

researchers have developed a CDI application that uses graphene-like nanoflakes as

electrodes for capacitive deionization. They found that the graphene electrodes resulted

in a better CDI performance than the conventionally used activated carbon materials.

Carbon dioxide capture

Before CO2 can be stored in Carbon dioxide Capture and Storage (CCS) schemes, it must

be separated from the other waste gases resulting from combustion or industrial

processes. Most current methods used for this type of filtration are expensive and

require the use of chemicals. Nanotechnology techniques to fabricate nanoscale thin

membranes could lead to new membrane technology that could change that.

Hydrogen production from sunlight - artificial photosynthesis

Companies developing hydrogen-powered technologies like to wrap themselves in the

green glow of environmentally friendly technology that will save the planet. While

hydrogen fuel indeed is a clean energy carrier, the source of that hydrogen often is asdirty as it gets. The problem is that you can't dig a well to tap hydrogen, but hydrogen

has to be produced, and that can be done using a variety of resources.

The dirtiest method at least until highly efficient carbon capture and sequestration

technologies are developed is the gasification of coal (read more: "Nanotechnology

could clean up the hydrogen car's dirty little secret"). The cleanest by far would be

renewable energy electrolysis: using renewable energy technologies such as wind, solar,

geo- and hydrothermal power to split water into hydrogen and oxygen.

Artificial photosynthesis, using solar energy to split water generating hydrogen and

oxygen, can offer a clean and portable source of energy supply as durable as the

sunlight. It takes about 2.5 volts to break a single water molecule down into oxygen

along with negatively charged electrons and positively charged protons. It is theextraction and separation of these oppositely charged electrons and protons from water

molecules that provides the electric power.


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Working on the nanoscale, researchers have shown that an inexpensive and

environmentally benign inorganic light harvesting nanocrystal array can be combined

with a low-cost electrocatalyst that contains abundant elements to fabricate an

inexpensive and stable system for photoelectrochemical hydrogen production.

Green Nanotechnology

There is a general perception that nanotechnologies will have a significant impact on

developing 'green' and 'clean' technologies with considerable environmental benefits.

The best examples are the use of nanotechnology in areas ranging from water treatment

to energy breakthroughs and hydrogen applications. As a matter of fact, renewable

energy applications probably are the areas where nanotechnology will make its first

large-scale commercial breakthroughs (see: Nanotechnology applications could provide

the required energy breakthroughs).

Conflicting with this positive message is the growing body of research that raises

questions about the potentially negative effects of engineered nanoparticles on human

health and the environment. This area includes the actual processes of manufacturing

nanomaterials and the environmental footprint they create, in absolute terms and in

comparison with existing industrial manufacturing processes (read more:

"Nanotechnology - not that green?"). In order to make any conclusive observations,'green' nanotechnology requires a full life cycle assessment like any other industrially

manufactured products.

A white paper ("Green Nanotechnology Challenges And Opportunities"; pdf) issued by the

ACS Green Chemistry Institute in partnership with the Oregon Nanoscience and

Microtechnologies Institute addresses the critical challenges to advancing greener

nanotechnology.

Researchers agree that the safest possible future for advancing nanotechnology in a

sustainable world can be reached by using green chemistry. Green chemistry means

designing chemical products and processes in a way that reduces or eliminates

hazardous substances from the beginning to end of a chemical products life cycle. The

practice began in the United States with the passage of the Pollution Prevention Act of1990, which established a national policy to prevent or reduce pollution at its source

whenever feasible. Reducing pollution at the source, according to the act, "is

fundamentally different and more desirable" than managing waste and controlling

pollution. Since then, the EPA Green Chemistry Program has built collaborations with

academia, industry, other government agencies, nongovernmental organizations and

international partners to promote pollution prevention through green chemistry.

As the report "Green Nanotechnology: It's easier than you think" (pdf) states: "Green

nanotechnology offers the opportunity to head off adverse effects before they occur.

Green nanotechnology can proactively influence the design of nanomaterials and

products by eliminating or minimizing pollution from the production of the nanomaterials,taking a life cycle approach to nanoproducts to estimate and mitigate where

environmental impacts might occur in the product chain, designing toxicity out of

nanomaterials and using nanomaterials to treat or remediate existing environmental

problems. Green nanotechnology does not arise de novo; rather, it builds on the

principles of green chemistry and green engineering and focuses them through a new

lens on the unique and often counterintuitive effects that occur in nanoscale materials.

Apart from the obvious areas of using nanomaterials in the areas of solar cells, biofuels

and fuel cells, green nanotechnology applications might involve a clean production

process, such as synthesizing nanoparticles with sunlight or the recycling of industrial

waste products into nanomaterials, such as turning diesel soot into carbon nanotubes.

Just as an aside: there is some truly green nanotechnology: growing nanomaterials inplants however this will never address industrial production of nanomaterials.

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