I am learning to understand nanotechnology2.5 Nanoscience & 2.5 Nanoscience & NanotechnologyNanotechnology

Keywords:Keywords: Nanometre, nanoparticles, nanotechnology

I am learning to understand nanotechnology

Outcomes: Outcomes: I will demonstrate I understand at I will demonstrate I understand at Grade C byGrade C by• State what nanotechnology is and the size involved.• Explain the properties of nanotechnology.• Explain the applications of nanotechnology.

Objectives: Objectives: I will understandI will understand• Nanoscience refers to structures that are 1–100 nm in size, of the order of a few hundred atoms. Nanoparticles show different properties to the same materials in bulk and have a high surface area to volume ratio which may lead to new computers, new catalysts, new coatings, highly selective sensors, and stronger and lighter construction materials.• to evaluate developments and applications of new materials, e.g. nanomaterials, smart materials.

I am learning to understand nanotechnology

Courtesy Sandia National Courtesy Sandia National Laboratories, Laboratories,

SUMMiTTM Technologies, SUMMiTTM Technologies, www.mems.sandia.govwww.mems.sandia.gov

C2 2.5 NanoscienceWhat can we do with nanoscience?

I am learning to understand nanotechnology

Imagine a machine that can build a copy of itself…

I am learning to understand nanotechnology

Now imagine that the machine built a smaller copy of itself…

I am learning to understand nanotechnology

Now imagine that the smaller machine built a smaller copy of itself…

I am learning to understand nanotechnology

Now imagine that the smaller machine built a smaller copy of itself… And that one made a smaller copy… And … well you get the picture! How far could we go? Well, we don’t really know.

I am learning to understand nanotechnology

Technology working with tiny machines may seem like science fiction but this is exactly what nanotechnologists are doing today.At the moment they use simple ‘nanoparticles’ rather than machines but the principle is the same. This slide shows some of the existing projects.

Windows that clean Windows that clean themselves?themselves?

Chemistry labs on a piece of Chemistry labs on a piece of card?card?

Sticky tape that doesn’t need Sticky tape that doesn’t need glue?glue?

Socks that don’t smell?Socks that don’t smell?

I am learning to understand nanotechnology

Titanium oxide nanoparticles Self-cleaning glass is covered with a thin titanium dioxide coating. Even on cloudy days, the layer allows ultraviolet light from the Sun to oxidize organic dirt and loosen it from the surface. Raindrops slide down normal glass, leaving dirt streaks and evaporated spots. Self-cleaning glass forces water to spread out evenly in a sheet, washing away dirt loosened by the photocatalytic action.

I am learning to understand nanotechnology

I am learning to understand nanotechnology

The smell in smelly socks comes from the bacterial breakdown of oils released by your skin. We can’t stop the skin releasing these chemicals but we can stop the bacteria working. Nanoparticles of silver inhibit bacterial growth and so prevent the smell. Silver particles are also used in sticking plasters for cuts. Why?

I am learning to understand nanotechnologyTesting for some chemicals needs expensive labs and can take hours or days to produce a result.We have now developed ways to encapsulate chemical reagents onto cards. These react with the substances that would normally need a whole lab to detect. In this way simple tests can detect viruses or other chemicals in the field and guide doctors in treatment.

I am learning to understand nanotechnologyThe hairs on the feet of geckos are so small that they can stick to individual molecules! Nanotechnologists can now coat a tape with sticky hairs of the same size. This means it sticks to anything - and needs no glue.

I am learning to understand nanotechnologyHuman hair So how big is a

nanoparticle? One of the circles opposite is a grain of silver added to (non) smelly socks. Compare this to a human hair. Can you spot the silver grain?

I am learning to understand nanotechnologyHuman hair

This is the correct size!

I am learning to understand nanotechnology

What is nanotechnology?What is nanotechnology?Nanotechnology involves the study and use of extremely small substances, often called nanoparticles.

Nanoparticles are very small, less than 100 nm across, but just how small is that?

The word ‘nano’ comes from the Greek word which means ‘dwarf’.

A nanometre (nm) is 0.000 000 001 metre (or 10-9 m). That’s one millionth of a millimetre.

I am learning to understand nanotechnology

I am learning to understand nanotechnology

Properties of nanoparticles – movementProperties of nanoparticles – movementForces affect nanoparticles more because of their small size.

Imagine being the size of a nanoparticle and going for a swim!

Swimming would feel like being in treacle because it is hard for such tiny particles to move through water molecules.

Nanoparticles are so small that gravity gravity has much less effect on themhas much less effect on them. So if you tried to jump into the pool, you might not go in the direction expected.

Walking to the pool would be difficult because air particles would bump into you and knock you all over the place.

I am learning to understand nanotechnology

Properties of nanoparticles – appearanceProperties of nanoparticles – appearanceNanoparticles also interact differently with light.

Normally, gold metal appears gold in colour. However, nanoparticles of gold in solution appear red and blue in colour.

Different-sized nanoparticles of gold give different coloured solutions.

Smaller nanoparticles appear red in solution, while slightly larger nanoparticles appear blue

I am learning to understand nanotechnology

Properties of nanoparticles – surface areaProperties of nanoparticles – surface area

Nanoparticles have a much bigger surface area to volume ratio than larger particles.

Nanoparticles have more atoms or molecules nearer the surface than larger particles.

low surface area to volume ratio

high surface area to volume ratio

This is very useful for substances such as catalysts.

In reactions, nanoparticles are able to react more quickly. This is because more atoms in a nanoparticle can be in contact with the reactant, than in a larger particle.

I am learning to understand nanotechnology

I am learning to understand nanotechnology

What’s this?What’s this?

I am learning to understand nanotechnology

What are the physical properties of CWhat are the physical properties of C6060??

It is a black solid at room temperatureblack solid at room temperature which does not does not conduct electricity.conduct electricity.

The physical properties of buckminsterfullerene are:

It is insoluble in water but insoluble in water but dissolves in petroldissolves in petrol to form a deep red solution.

Its molecules are strong and hard, strong and hard, but elasticbut elastic, like a football. They can be squashed to 70% of their normal size, but bounce back

I am learning to understand nanotechnology

What are the chemical properties of CWhat are the chemical properties of C6060??The chemical properties of buckminsterfullerene include:

The molecules can be used as cages to molecules can be used as cages to trap atomstrap atoms and smaller molecules inside them.

The molecules can be joined together to make bigger fullerene structures.

The surface of CThe surface of C6060 molecules can be molecules can be coated with other atomscoated with other atoms. For example, coating with hydrogen makes a smooth substance that is even more slippery than Teflon.

I am learning to understand nanotechnology

More about fullerenesMore about fullerenesC60 molecules are also known as ‘buckyballsbuckyballs’.

C70 molecules, which are shaped like a rugby ball.

Buckybabies, with less than sixty carbon atoms.

Fuzzyballs, with a coating of hydrogen atoms.

Giant fullerenes, with many more than sixty carbon atoms.

Since the discovery of this first fullerene, other types of fullerenes that have been made include:

I am learning to understand nanotechnology

What are the uses of fullerenes?What are the uses of fullerenes?

Non-stick slippery coatings for machinery, which act like miniature ball bearings.

Some of the uses of fullerenes that scientists are currently working on include:

Cages to hold drug molecules that can be delivered directly into the body.

Molecular sieves, which traps large particles like viruses while allowing smaller, healthy particles to pass through.

Chemical sponges to soak up toxic substances in the body.

I am learning to understand nanotechnology

BONDINGWHY?

IONIC BONDS

COVALENT BONDS

UNREACTIVE?

IONIC LATTICE

GIANT STRUCTURES

DIATOMICMOLECULES

MACROMOLECULES

DIAMOND METALLIC BONDING

ALLOTROPES OF CARBON

GRAPHITE SILICA

FORMATION GIANT METALLIC

STRUCTURES

MALLEABLE DUCTILE

‘BUCKYBALLS’

PHYSICALPROPERTIESUSES

CHEMICALPROPERTIES

FULLERENES

I am learning to understand nanotechnology

What are nanotubes?What are nanotubes?Nanotubes are another form of fullerene. They are tubes of carbon hexagons, like sheets of graphite rolled into cylinders.

Nanotubes have many useful properties, including:

very high tensile strength unique electrical properties good heat conductance.

Multi-walled nanotubes exist. In these, several tubes can rotate and slide within in each other, almost without frictionalmost without friction.

Metal atoms can be attached to the outer surface of the tubes.

With these properties, what might nanotubes be used for?

I am learning to understand nanotechnology

What are the uses of nanotubes?What are the uses of nanotubes?The properties of nanotubes make them useful in many ways.

Thinner, lighter TV screens.

Strong, light waterproof fabrics.

Smaller, thinner optical fibres.

Smaller, lighter electrical circuits.

Stronger building materials.

Some examples include:

I am learning to understand nanotechnology

BONDINGWHY?

IONIC BONDS

COVALENT BONDS

UNREACTIVE?

IONIC LATTICE

GIANT STRUCTURES

DIATOMICMOLECULES

MACROMOLECULES

DIAMOND METALLIC BONDING

ALLOTROPES OF CARBON

GRAPHITE SILICA

FORMATION GIANT METALLIC

STRUCTURES

MALLEABLE DUCTILE

‘BUCKYBALLS’

PHYSICALPROPERTIESUSES

CHEMICALPROPERTIES

FULLERENES

‘NANOTUBES’

PROPERTIES

USES

I am learning to understand nanotechnology

Future uses of nanoparticles – medicineFuture uses of nanoparticles – medicine

Nano-capsules of drugs that will target cancer cells only.

Nano-electronic implants in the retinas of blind people, which communicate with cells, making it possible for them to see.

Nano-coatings on hip and joint replacements to prevent rejection.

Nano-scaffolds will be able to support the growth of new skin and body tissue.

Nano-sensors inside clothes, or even inside our bodies, that will be able to run health checks or deliver medicine.

I am learning to understand nanotechnology

Other future uses of nanotechnology include:

Nano-scale microchips and wires for smaller electrical devices.

Nano-scale solar cells to trap solar energy, mimicking photosynthesis.

Nano-size containers to store hydrogen, being used as a fuel.

Paints and glues containing nanoparticles will be lighter, stronger and need less solvents.

Composite materials made from nanostructures, which are stronger, harder and lighter.

I am learning to understand nanotechnology

I am learning to understand nanotechnology

BONDINGWHY?

IONIC BONDS

COVALENT BONDS

UNREACTIVE?

IONIC LATTICE

GIANT STRUCTURES

DIATOMICMOLECULES

MACROMOLECULES

DIAMOND METALLIC BONDING

ALLOTROPES OF CARBON

GRAPHITE SILICA

FORMATION GIANT METALLIC

STRUCTURES

MALLEABLE DUCTILE

‘BUCKYBALLS’

PHYSICALPROPERTIESUSES

CHEMICALPROPERTIES

FULLERENES

‘NANOTUBES’

PROPERTIES

USES

FUTURE

I am learning to understand nanotechnology

I am learning to understand nanotechnology

I am learning to understand nanotechnology

I am learning to understand nanotechnology

EXAM TIPS:• Nanoscience is about structures that

are a few nanometres in size.• Nanoparticles behave differently to

the same materials in bulk.• Nanometre means one billionth of a

metre eg 10-9m• You need to know the types of

applications but you do not need to remember. You will get information in a question and you will be asked to apply your understanding.

I am learning to understand nanotechnology

Outcomes: Outcomes: I will demonstrate I understand at I will demonstrate I understand at Grade C byGrade C by• State the physical properties of metals.• Match the uses of certain metals with specific properties.• Explain in detail why metals are malleable and ductile.Outcomes: I will demonstrate I understand at Outcomes: I will demonstrate I understand at Grade A byGrade A by• Explain why metals conduct electricity and heat in terms of delocalised electrons in their structures. [HT ]

Objectives: Objectives: I will understandI will understand• That metals conduct electricity and heat, and can be bent and shaped.• Why metals can be bent and shaped.• Why metals can conduct electricity and heat. [HT only]

I am learning to understand nanotechnology

Summary notesSummary notes• When atoms are arranged into very small particles they behave

differently to ordinary materials made of the same atoms.• A nanometre is one billionth of a metre and nanoparticles are a few

nanometres in size.• They contain a few hundred atoms arranged in a particular way.• Their structures and very small sizes give them new properties that can

make them very useful materials.• Nanoparticles have very large surface areas, exposing many more

atoms at their surface than normal materials.• Electrons can move through them more easily than ordinary materials. • They can be very sensitive to light, heat, pH, electricity and magnetism.• Nanotechnology uses nanoparticles as very selective sensors, highly

efficient catalysts, new coatings and construction materials with special properties, and to make drugs more effective.

I am learning to understand nanotechnology

Check your understandingCheck your understanding1. About how many atoms are there in a typical

nanoparticle?2. Why do nanoparticles have different

properties to ordinary materials?3. Suggest 3 ways in which nanotechnology is

being used.

ANSWERS:

1. A few hundred (200-5000

2. Their structure (may be different) and their very small size.

3. 3 forms: sensors, catalysts, coatings, construction coatings, drug delivery/ release, microprocessors/ computers.

CLICK AGAIN FOR THE ANSWERSCLICK AGAIN FOR THE ANSWERS

I am learning to understand nanotechnology

Extra Notes

I am learning to understand nanotechnology

When did nanotechnology start?When did nanotechnology start?Nanotechnology is not a new idea. Nanoparticles have in fact been used by people for thousands of years.

The Egyptians used ink containing nanoparticles of black pigment.

Nanoparticles of gold and silver have also been used since the 10th century to colour ceramics and stained glass.

Nanoparticles of lead sulfide were used by the Romans to dye their hair black.

I am learning to understand nanotechnology

Are there nanoparticles in nature?Are there nanoparticles in nature?Natural nanoparticles also exist. For example:

Nanotechnology scientists try to copy natural nanoparticles to make new materials that are useful.

Insects and lizards are able to stick to walls because of the nanostructures on their feet.

Butterflies’ wings contain shiny reflective nanocrystals.

Spiders’ webs are made of super-strong nanofibres.

Chloroplasts in plant cells are nanofactories that harness the Sun’s energy to make glucose.

I am learning to understand nanotechnology

When did modern nanotechnology start?When did modern nanotechnology start?

The idea of nanotechnology was suggested in 1959 by Richard Feynman, an American physicist.

The prize was claimed just a year later by Bill McLellan, a scientist working in California.

He offered a $1000 prize for the first working motor less than 1/64th of an inch across (smaller than a pinhead).

Scientists have since made structures smaller and smaller. This work is now called nanotechnology, a term first used in 1974 by Norio Taniguchi, a materials scientist in Japan.

I am learning to understand nanotechnology

How has nanotechnology developed?How has nanotechnology developed?

As scientists have steadily made things smaller, they have needed new pieces of equipment to help them.

In 1989, an STM was used to move 35 xenon atoms onto a tiny piece of nickel.

In 1981, the scanning tunnelling microscope (STM) was invented and allowed scientists to see the nano-world.

Using an STM, it is possible to see individual atoms and even move them around.

The atoms spelled the name of the company that the scientists worked for. What was it called?

I am learning to understand nanotechnology

I am learning to understand nanotechnology

Using nanoparticles – healthUsing nanoparticles – healthNanoparticles are already used in various ways.

Plasters and bandages can contain nanocrystals of silver, because it is toxic to bacteria. Silver can even be woven into athletes' socks to kill the bacteria that makes socks smell.

Sunscreen contains nanoparticles of zinc oxide and titanium oxide, which absorb and reflect harmful UV rays from the Sun.

These particles are so small that they are invisible on the skin. Before nanoparticles, the oxide particles were big enough to be seen, so the sunscreen looked white on skin.

I am learning to understand nanotechnology

Using nanoparticles – cleaningUsing nanoparticles – cleaningNanoparticles can also help to keep things clean. Could dirty football shirts be a thing of the past?

Fabrics have been developed with nano-coatings, which repel liquid and resist stains.

Windows that are self-cleaning have been developed by British scientists. How could self-cleaning windows work?

Spillages on treated fabrics will not soak into the fabric, but form beads of liquid, which can simply be wiped away.

I am learning to understand nanotechnology

I am learning to understand nanotechnology

I am learning to understand nanotechnology

Is nanotechnology safe?Is nanotechnology safe?As nanotechnology becomes more commonplace, how careful do we need to be?

What problems might be associated with nanotechnology?

Do you think this is a realistic possibility?

In 1986, a researcher called Eric Drexler made a prediction about nanoparticles in the future.

He suggested that because nanoparticles can build themselves into molecules by self-assembly, self-replicating nano-robots will consume the atoms of the world as they replicate, eventually turning everything into a “grey goo”.

I am learning to understand nanotechnology

Glossaryallotrope – A structurally different form of an element,

which has different physical properties.

bottom-up – A method of building up nanoparticles one atom at a time.

buckminsterfullerene – The hollow, spherical fullerene molecule made up of 60 carbons atoms.

fullerenes – The family of carbon allotropes, in which the atoms are joined together to make hollow spheres or tubes.

nanometre – A measurement equal to 0.000 000 001

metres.

I am learning to understand nanotechnology

nanoparticle – A particle which measures less than 100

nanometres in size.

nanotechnology – The study of nanoparticles and their uses.

nanotubes – Fullerene molecules made of carbon atoms arranged into hollow cylinders.

self-assembly – A method of building nanoparticles in which atoms and molecules arrange themselves.

top-down – A method of making nanoparticles by starting with larger particles and shaping them into smaller pieces.