NANO-TECHNOLOGY ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? The Answer: Nanotechnology...
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Transcript of NANO-TECHNOLOGY ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? The Answer: Nanotechnology...
NANO-TECHNOLOGY
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The Answer:
Nanotechnology
makes it
Possible!!
Nanometer (nm) = one billionth of a meter
Definition of “Nano”:One billionth (10x-9)
Scientific Terms:A human hair is 10,000 nm wide
WHAT DO YOU MEAN BY NANO
A field of applied science focused on design, formation, identification and application of materials and devices on the nanoscale.
Definition “Nanotechnology”:
Two Methods of Making Nanoparticles
“Top Down”
Cut object smaller and smaller until attain size needed.
“Bottom Up”
Add atoms together one by one to attain correct property.
Vs.
Health risks and environmental issues
Molecular manufacturing allows the cheap creation of incredibly powerful devices and products.
How many of these products will we want? What environmental damage will they do?
The range of possible damage is vast, from personal low-flying supersonic aircraft injuring large numbers of animals to collection of solar energy on a sufficiently large scale to modify the planet's equilibrium and directly affect the environment. Stronger materials will allow the creation of much larger machines, capable of excavating or otherwise destroying large areas of the planet at a greatly accelerated pace.
Page-1
Health risks and environmental issues
ROS and free radical production is one of the primary mechanisms of nanoparticle toxicity; it may result in oxidative stress, inflammation, and consequent damage to proteins, membranes and DNA .The extremely small size of nanomaterials also means that they are much more readily taken up by the human body than larger sized particles.
Once in the blood stream, nanomaterials can be transported around the body and are taken up by organs and tissues including the brain, heart, liver, kidneys, bone marrow and nervous system
Other properties of nanomaterials that influence toxicity include: chemical composition, shape, surface structure, surface charge, aggregation and solubility , and the presence or absence of functional groups of other chemicals .
Page-2
(reactive oxygen species )
Does Nanotechnology Address Teaching Standards?
Nanotechnology Idea Standard it can address
Nanomaterials, such as MR (magneto-resistive) fluids in security
Science and technology in local, national, and global challenges
Richard P. Feynman’s talk, “There is plenty of room at the bottom”. Feynman had a vision.
Science as a human endeavor, Nature of scientific knowledge, Historical perspective
Nanocosmetics and nanoclothing Science as a human endeavor, Science and technology in local, national, and global challenges
Nanotechnology and Science Ethics Science and technology in local, national, and global challenges, Science as a human endeavor, Historical perspective, Natural and human-induced hazards, Population Growth, Personal and Community Health
Standard it can address
Structure of Atoms
Structure and properties of matter, Personal and Community Health
Chemical Reactions
Motion and Forces, Abilities of technological design, Understanding about science and technology
Conservation of Energy and increase in disorder, Interactions of energy and matter, Natural Resources
Personal and Community Health, Population Growth, Environmental Quality, Natural and human-induced hazards
Nanotechnology Idea
The idea of “Nano” – being small
Nanomaterials have a high surface area(nanosensors for toxins)
Synthesis of nanomaterials and support chemistry (space propulsion)
Shape Memory Alloys
Nanocrystalline Solar Cells
Nanocoatings resistive to bacteria and pollution
Does Nanotechnology Address Teaching Standards?
Imagine a soldier that has a uniform that can change from desert, to winter, to forest camouflage by using current from a small battery to rearrange alignment of the molecules!
An Example of a Nanotechnology Experiment, Which Addresses the Standards: Constructing
Nanocrystalline Solar Cells Using the Dye Extracted From Citrus
Four main parts:1. Nanolayer2. Dye3. Electrolyte4. 2 electrodes
Nanocrystalline Solar Cells: The MaterialsMaterials:
1. (2) F-SnO2glass slides
2. Iodine and Potassium Iodide
3. Mortar/Pestle4. Air Gun5. Surfactant (Triton X
100 or Detergent)6. Colloidal Titanium
Dioxide Powder7. Nitric Acid8. Blackberries,
raspberries, green citrus leaves etc.
9. Masking Tape10. Tweezers11. Filter paper12. Binder Clips13. Various glassware14. Multi-meter
Nanocrystalline Solar Cells
Main component: Fluorine doped tin oxide conductive glass slides
Test the slide with a multimeter to determine which side is conductive
Synthesis of the Nanotitanium Suspension
Add 9 ml (in 1 ml increments) of nitric or acetic acid (ph3-4) to six grams of titanium dioxide in a mortar and pestle.Grinding for 30 minutes will produce a lump free paste.1 drop of a surfactant is then added ( triton X 100 or dish washing detergent).Suspension is then stored and allow to equilibrate for 15 minutes.
Procedure
Coating the CellAfter testing to determine which side is conductive, one of the glass slides is then masked off 1-2 mm on THREE sides with masking tape. This is to form a mold.
A couple of drops of the titanium dioxide suspension is then added and distributed across the area of the mold with a glass rod.
The slide is then set aside to dry for one minute.
Calcination of the Solar Cells
After the first slide has dried the tape can be removed.
The titanium dioxide layer needs to be heat sintered and this can be done by using a hot air gun that can reach a temperature of at least 450 degrees Celsius.
This heating process should last 30 minutes.
Dye Preparation
Crush 5-6 fresh berries in a mortar and pestle with 2-ml of de-ionized water.The dye is then filter through tissue or a coffee filter and collected.As an optional method, the dye can be purified by crushing only 2-3 berries and adding 10-ml of methanol/acetic acid/water (25:4:21 by volume)
Dye Absorption and Coating the Counter Electrode
Allow the heat sintered slide to cool to room temperature.
Once the slide has cooled, place the slide face down in the filtered dye and allow the dye to be absorbed for 5 or more minutes.
• While the first slide is soaking, determine which side of the second slide is conducting.
• Place the second slide over an open flame and move back and forth.
• This will coat the second slide with a carbon catalyst layer
Assembling the Solar CellAfter the first slide had absorbed the dye, it is quickly rinsed with ethanol to remove any water. It is then blotted dry with tissue paper.Quickly, the two slides are placed in an offset manner together so that the layers are touching. Binder clips can be used to keep the two slides together.
• One drop of a liquid iodide/iodine solution is then added between the slides. Capillary action will stain the entire inside of the slides
Nanotechnology for the Environment
Nanotechnology and the Environment
“The emerging fields of nanoscience and nanoengineering are leading to unprecedented understanding and control over the fundamental building blocks of all physical things. This is likely to change the way almost everything - from vaccines to computers to automobile tires to objects not yet imagined - is designed and made.”
- Interagency Working Group on Nanoscience, Engineering, and Technology Report (1999)
Nature of nanoparticles themselves.
The bad…
• As nano-xyz is manufactured, what materials are used?
Characteristics of the products made.
Manufacturing processes involved.
• What waste is produced?
• Are toxic substances used in the manufacturing of nano-xyz?
• What happens when nano-xyz gets into the air, soil, water, or biota?
Cd(CH3)2
H2S gas
Cadmium sulfide (CdS) “Quantum dots”
Enter the environment
Bio/Enviro/other applications
+
Avoiding the Negative
Are there more caring gentle precursor materials or synthetic methods that can be used to make the quantum dots?
How are these semiconductor nanoparticles gently introduced to their target?
Will it be possible to recover the quantum dots for reuse?
Are there measures that can be taken now to minimize or avoid the negative impact quantum dots (or other nanotechnologies) may have on the environment?
CdS CdS
CdS CdS
CdS
Nanotechnology has the potential to substantially benefit environmental quality and sustainability through
• Pollution prevention
• Treatment
• Remediation
• Information
Nanotechnology and the Environment
The good…“As EPA looks to the future, it will need to employ innovative approaches and sound science to
investigate complex, interdisciplinary
problems in environmental
protection.”
- EPA FY 2001 Annual Report
Involved in making a manufacturing process environmentally caring
An environmentally caring material or manufactured product that replaces toxic substances or minimizes raw materials.
Synthetic or manufacturing processes which can occur at ambient temperature and pressure.
Nanotechnology for pollution prevention
Use of non-toxic catalysts with minimal production of resultant pollutants.
Use of aqueous-based reactions.
Build molecules as needed --“just in time.”
Nanoscale information technologies for product identification and tracking to manage recycling, remanufacture, and end of life disposal of solvents.
• Biomimetic methods of organizing metal particles 1.5 nanometers in diameter.
Biomolecular nanolithography5mm
• Assembling the particles on a biopolymer template or scaffold stretched out on a surface.
• Nanostructures are organized into well-defined chip architectures, such as lines and grids.
• Process eliminates the current process chemicals that are harmful to the environment.
• Nanoscale assemblies have been made that demonstrate stable, room-temperature electrical behavior that may be tolerant of defects and useful in building nanoscale circuits.
End-of-pipe management and cleanup of pollution
Treatment & Remediation
Iron Treatment Walls…
Used in groundwater treatment for many years. Iron chemically reduces organic and inorganic environmental contaminants. Currently involves granular or “microscale” iron ( 50 mm or 50,000 nm).
and Nanotechnology
Nanosized iron enhances the reaction. Enhanced further by coupling with other metals (Fe/Pd)* on the nanoscale. Nano Fe0 is more reactive and effective than the microscale. Smaller size makes it more flexible -- penetrates difficult to access areas.
Nanosized zinc oxide (ZnO) “senses” organic pollutants indicated by change in visible emission signal.
Sensing capability means that the energy-consuming oxidation stage only occurs when the pollutants present.
“Sense and Shoot” Approach to
Pollution Treatment
“Sense and Shoot” Approach to
Pollution Treatment
The ZnO “shoots” the pollutants via photocatalytic oxidation to form more environmentally caring compounds.
Multifunctionality and “smartness” is highly desirable for environmental applications.
Dual role of ZnO semicondouctor film as a sensor and photocatalyst
>300 nm
UV
Used for • Process control, compliance
and ecosystem monitoring, and data/information interfaces.
Sensors• Molecules adsorb on surface of micro
cantilever, causes a change in surface stress, cantilever bends.
Single Molecule Detection
• Used to detect chemicals using either a specific reaction between analyte and sensor layer or chem/physisorption processes.
• Applications to bio-toxins as well.
Need to be • Low cost, rapid, precise, and
ultra sensitive.• Operated remotely and
continuously, in laboratories, and in real time.
Science and Engineering approaches are needed that offer new capabilities to prevent or treat highly toxic or persistent pollutants, and that result in the more effective monitoring of pollutants or their impact in ways not currently possible.
Conclusions
Nanoscience, engineering, and technology holds great potential for the continued improvement of technologies for environmental protection. The recent breakthroughs in creating nanocircuitry, give further evidence and support the predictions that nanoscale science and engineering “will most likely produce the breakthroughs of tomorrow.”
BUT the environmental implications (nano in the environment) need to be considered as we consider nano for the environment.
The Coming Nanotechnology Revolution
The Coming Nanotechnology Revolution
Not just new products — a new means of production Manufacturing systems that make more manufacturing
systems — exponential proliferation Accelerated product improvement — cheap rapid
prototyping Affects all industries— general-purpose technology Inexpensive raw materials, potentially negligible capital
cost — economic discontinuity Portable, desktop-size factories — social disruption Impacts will cross borders — global transformation
Current research
Space-filling model of the nanocar on a surface, using fullerenes as wheels.
Graphical representation of a rotaxane, useful as a molecular switch.
This device transfers energy from nano-thin layers of quantum wells to nanocrystals above them, causing the nanocrystals to emit visible light
Current research
Who defines what is nanotechnology?
Scientists– Eric K. Drexler. Engines of Creation, 1986– Richard Smalley. “Of Chemistry, Love, and Nanobots”
Scientific American, September 2001Political Leaders– H.R. 766 ; 108th Congress, 1st session (2003) ” To provide
for a National Nanotechnology Research and Development Program , and for other purposes”
Media– Feder, Barnaby. “Technology: a look at the dark side” New
York Times May 17, 2006Standards-setting Organizations– American National Standards Institute “ANSI-NSP priority
recommendations related to nanotechnology standardization needs” November 14, 2004.
Audience of the NEB
ScientistsEngineersBusiness leadersPolicy makersScholars & ResearchersStudentsGeneral PublicAll stakeholders
Computers
BIG STEPS in Economic, Social, and Political
History
BIG STEPS in Economic, Social, and Political
History
Time
Change
Automobiles
Railways
Steam Engines
Time
Change
BIG STEPS in Economic, Social, and Political
History
BIG STEPS in Economic, Social, and Political
History
Not Steps, but S-Shaped CurvesNot Steps, but S-Shaped Curves
Time
Change
Time
Change
Not Steps, but S-Shaped CurvesNot Steps, but S-Shaped Curves
Time
Change
Not Steps, but S-Shaped CurvesNot Steps, but S-Shaped Curves
Societ
al
Im
pact
s
Time
Industrial RevolutionsIndustrial
Revolutions
Societ
al
Im
pact
s
Time (Measured in
decades)
Industrial RevolutionsIndustrial
Revolutions
Societ
al
Im
pact
s
Time (Measured in
YEARS)
Nanotechnology Revolution
Nanotechnology Revolution
Societ
al
Im
pact
s
Time
Accelerated ImpactsAccelerated Impacts
Industrial Revolutions
Molecular Manufacturing
Revolution
Societ
al
Im
pact
s
Time
The Next Big StepThe Next Big Step
Steam Engines
Computers
Railways
Automobiles
(Middle Ages)
Societ
al
Im
pact
s
Time
Steam Engines
Computers
Railways
Automobiles
(Middle Ages)
Nanotechnology
The Next Big StepThe Next Big Step
Nanotechnology
Societ
al
Im
pact
s
Time
The Next Big StepThe Next Big Step
Steam Engines
Computers
Railways
Automobiles
(Middle Ages)
Once we have gained perspective, we can begin to make wise decisions for
a better and safer nano future!
Once we have gained perspective, we can begin to make wise decisions for
a better and safer nano future!
As for nanotechnology’s
transformative and disruptive
impacts, we’re on the roller
coaster heading toward the
big climb. Progress is occurring
every day, taking us closer,
even if we don’t notice the
gradual incline. Soon,
however, the curve
will sharpen and
take us rapidly into
a future for which
we may not
be prepared.
The American Heritage Sci-Tech Encyclopedia Wikipedia
Intelligence Encyclopedia
Hacker Slang Modern Science Britannica Concise Encyclopedia.
SOME RELATED LINKS
THANK YOU