Performance MaterialsTextiles

Module Outcomes• Understand the polymer structure of

synthetic and natural fibres and textiles

• Understand how properties of polymers influence textile applications

• Have an awareness that unique textiles and other polymer-based materials with novel properties can be developed with nanotechnology.

What If?What if you could knit a car?

• Lauren Porter knitted this car for her art degree at Bath Spa University

• Could be possible using carbon nanotube-enhanced textile and then setting in resin.

Image: Courtesy Bath Spa University

What If?What if your t-shirt could stop a bullet?

Image: 9229859@N02@flickr

• Professor Liangchi Zhang at the University of Sydney is investigating ballistic-resistant textiles using carbon nanotubes.

What Is A Textile?

Image: decor8@flickr

• Textiles are materials that are made of fibres

• Fibres in turn are made up of giant molecules called polymers.

Spot The Polymer

Image: ierrroen@flickr, slipstitch@flickr, ericcastro@flickr

• We rely on polymers daily!• Polymers are made up of many molecules

strung together to form really long chains.

Monomers Are The Subunits Of Polymer

• The repeating unit in a long polymer chain is called a monomer

• Monomers join by addition reactions or condensation reactions to form polymers.

Addition Polymerisation

Image: coyotejack@ flickr

• Two monomers are joined by addition polymerisation when they are simply added on to the end of each other, and the process is repeated many times over

• Polypropylene money is an example.

Condensation Polymerisation

Image: coyotejack@flickr

• Two monomers are joined by condensation polymerisation in a reaction involving the loss of a molecule, usually watereg glucose + glucose maltose + water

• Naturally-occurring condensation polymers include cellulose, chitin, hair, fur, leather and feathers

• Nylon is a synthetic condensation polymer.

Natural Polymers

Image: aliciayeah @flickr, quinet@flickr, recyclethis@flickr

Monomer Polymer Origin Uses

glucose cellulose plants clothing, fabrics

amino acids keratin animalseg sheep, rabbit clothing, fabrics

amino acids silk caterpillar clothing, fabrics

isoprene rubber rubber trees toys, gloves

Synthetic Polymers

Image: aliciayeah @flickr, quinet@flickr, recyclethis@flickr

• Synthetic polymers like nylon were invented during World War II(America and its allies were at war with the countries that produced silk and rubber)

• Plastics are synthetic polymers, such as - polyethylene (used in cling film), - polystyrene (hot drink take-away cups) - Teflon (used for non-stick cookware)

• Synthetic fibres and plastics are composed of monomers which are extracted from crude oil and modified by chemists.

Types Of Fibres

FIBRES

Natural Synthetic

Plant based (cellulose):

CottonLinenHempJute

MineralAsbestos

(rarely used)

Animal Based (protein)

WoolSilk

CashmereAngora

MetalWires

FilamentsLurex

SyntheticNylon

PolyesterAcrylics

ElastomersPolypropylene

RegeneratedViscoseRayonCasein

Seaweed based

InorganicGlass

CarbonQuartz

Ceramics

Adapted from Elvins et al. (1995) ‘Materials Chemistry in Everyday Life’, Heinemann Chemistry in Context, Chemistry One Second Ed. Southbank Books, Port Melbourne.

Intermolecular Bonding

H20: ice H20: water H20: steamcool heat

• Intermolecular bonding = the way molecules “stick” together

• Molecules of water (H20) can form intermolecular bonds with each other, depending on the ambient temperature.

Image: snapr, kylemay, jenny-pics@flickr, © Dorling Kindersley

Intermolecular Bonding In Polymers

Image: © Dorling Kindersley

• Polymers can be stretchable, bouncy, sticky or hard, depending on how their atoms and molecules stick together. Intermolecular bonds can be formed between polymer chains that affect the properties of the final product

• An attractive force operates between polymer chains- if there are only weak interactions between polymers chains, then these long polymer molecules can slide over each other; such polymers are soft and can be stretchy, eg cling wrap- if there are rigid bonds between the polymer molecules, a harder, more brittle structure is formed, eg solid plastic. These can be created by using monomer molecules to join together long polymer chains.

Polymer Example: Polyethylene

Image: chitrasudar, lylamerle, foxtongue@flickr

• Apples release ethene gas when they ripen• Ethene gas molecules can be joined together to make a

polymer called polyethylene- if no links are formed between the chains then the polymer can be used to make cling wrap- if chains of polyethylene are linked together with extra ethene molecules via intermolecular bonds then hard plastic road barriers can be made.

Experiment 1 and 2Perform one or both of the Making and Investigating Plastics experiments

• Experiment 1 - Making Casein • Experiment 2 - Making Nylon to further explore the characteristics of

polymers.

Chemical Control Of Synthetic Textile Properties

• The properties of a synthetic textile can be controlled chemically by modifying the polymers involved in their synthesis

• Altering reaction conditions can affect how strongly the polymer molecules are attracted to one another, and in turn, how strong or flexible the fibre and textile will be

• Atoms or small molecules can be added to the monomers or the polymers to give them unique properties.

Nanotubes In Unique Textiles

Image: Courtesy Ray Baughman

• Carbon nanotubes can be spun into fabric to form nanocomposite fibres- this is currently an area of research at CSIRO, Australia- very strong and yet lightweight fabrics are possible

• Spun carbon nanotubes can be 3x stronger than spider silk- made by bonding carbon nanotubes with the polymer PVA.

Half the threads in this textile are black carbon nanotube threads

Nanotubes In Unique Textiles

Images: © NanoTex, ralphlunden@flickr

• There are many fabric products on the market which currently use nanotechnology in their manufacture eg DuPont, NanoTex

• Stain free fabric employs custom-designed nano-sized whisker-like molecules attached to fabrics which fend off spills and resists stains without changing the material's characteristic look and feel.

Experiment 3Perform the Observing Fabric Properties Experiment to see the unique characteristics of nano fabrics.

Nano-Textiles: Military ApplicationsNano-fabrics offer the following possibilities to the military:

Image: soldiersmediacenter@flickr

- Instant camouflage to environment;- manipulate light to make soldiers invisible;- Change a shirt-sleeve into a splint or cast;- Possess built-in sensors of soldiers’ physical condition and location;- Weave radio communications directly into the uniform's fabric;- Automatically administer medicines & transmit vital signs to distant medics;- Provide impact protection materials and systems;- Provide chemical and biological protection.

Nano-textiles: Liquid Armour

Image: paulk@flickr

• Impact resistant: bullet proof, will also resist pointed objects such as needles, icepicks, swords

• Made from a ballistic fabric (eg Kevlar) filled with a shear thickening fluid - this is a water like liquid (polyethylene glycol) that contains silica nanoparticles

• Under normal conditions, the armour is like water but it stiffens on impact

• Materials such as this are perfect for combat- imagine Superman with a suit which allows flexibility for crime fighting while at the same time enabling him to protect vulnerable areas (so that’s why he wears his undies on the outside!)

• Since the material is also very lightweight it will not result in extra energy expenditure during movement (eg Superman flying).

Unique Textiles

Many companies are currently using nanotechnology to create unique textiles.

What If?What if your shirt could prevent body odour?

Image: © Dorling Kindersley

• Mushon is a nanotechnology-enabled deodorant- can be coated onto polymer fabrics such as nylon and polyester- has odour elimination and antibacterial properties

• Mushon was successfully tested by astronaut Tako Doi in his mission to the space station in 2008.

What If?What if your clothes could always smell like your favourite fragrance?

Image: derek7272@flickr

“ Research scientists at Bayer Chemicals have developed a new technology for ‘packaging’ fragrances in an ultra-thin nanofilm to form microcapsules. Leather and textiles sprayed with these microcapsules then release a soothing or exotic fragrance…..when subjected to pressure”.

What if polymers could sense and respond to your environment?

Image: Courtesy Gordon Wallace, Uni of Wollongong.

• Nanotechnology has been used to create conductive polymers- these polymers contain carbon nanotubes or other components which respond to the environment- examples include : ink jet-printed functional polymers which can detect volatile compounds; polypyrole polymer which expands and contracts (could be used for artificial muscles).

What if spinal patients could throw away their wheelchair forever…

Image: © Dorling Kindersley

• Carbon nanotubes may one day be used to repair the spinal cords of people who are paralysed.

• Scientists at the Bionic Ear institute in collaboration with University of Wollongong are developing polymers in gel or solid form to deliver agents that will encourage spinal cord repair

• Describing the technology, inventor of the Bionic Ear Professor Graeme Clark said “The polymers will create a scaffold for the neurons to grow along, while maintaining their viability and suppressing neural scar formation that could block nerve pathways”.

Intelligent Design In Polymers

• It is possible to create new types of polymers. They can be incorporated into clothes so that they light up or carry electric signals

• Phillips have designed a range of sensors that can be fitted to underwear. In the event of a health crisis, these can alert medical authorities- so that’s another reason for Superman to wear his undies on the outside! He can signal to approaching aircraft and call for help if necessary.

Superman

Image: loresjoberg@flickr

So we have a few ideas about why Superman wears his undies on the outside…

Superman

Image: loresjoberg@flickr

What other special What other special properties must properties must Superman’s suit Superman’s suit

have?have?

Superman’s Nanosuit Activity

• Divide into groups and consider: - why does Superman need such a resplendent item of clothing?- how does Superman use his suit to perform his duties as a superhero?- what special properties of Superman’s suit allow him to perform his duties?

Superman’s Nanosuit Activity• Superman has lost his suit. Apparently he left it in the

very last telephone box in Metropolis and while he was off saving the world, the phone company removed the box and destroyed it

• Being a nanotechnologist working for a textile factory, you have been offered the top secret contract to make Superman a gorgeous new version of his iconic outfit

• Using your knowledge of nano-scaled materials, explain what materials the suit will be made from, why you have chosen a particular material and how it exhibits the properties described.

Superman’s Nanosuit Activity

• SUPER PROPERTIES:- what special properties will the suit need to have? For example: when Superman stops bullets his suit is not damaged; what properties of the suit will allow him to absorb energy from the sun?

• FABRIC PROPERTIES:- Consider stretch, durability, colours. Superman needs to be able to move easily when he is chasing villains. Also it is very cold up in the stratosphere and he must resist heat on re-entry to the atmosphere

• CLEANING AND STORAGE: - How will the suit maintain its shiny lustre? Will Superman need to do the ironing before a rescue?

• SAFETY:- Materials must be non-hazardous to Superman, and it is important that aircraft and spacecraft can see him clearly

• AERODYNAMICS:- Superman needs to maintain a streamlined shape. His cape must provide him with adequate lift. He needs to alter the directions of the forces acting on him if he wants to change direction quickly. The cape must work efficiently on earth and in the stratosphere.

Consider the following points:

Summary• Polymers are evident all around us• Polymer characteristics depend on the

type of monomer and the intermolecular bonds operating

• Textiles with unique characteristics can be generated by incorporating nanotechnology into existing polymers.

Revision1. Explain what is meant by the term “textile”2. How has nanotechnology improved

textiles? 3. What are polymers?4. List 5 things that are made from polymers.5. What potential applications are there when

polymer chemistry is combined with carbon nanotubes?

6. Describe in detail one application of nanotechnology in textiles

7. List three fabrics/brand names that make clothes using nanotechnology.