Section A - Developments in new materials Flashcards
Define modern materials
Modern material is a material that has recently been developed for specific applications
Give examples of some modern materials
Graphene
Metal foam
Titanium
Coated metals
Liquid crystal display
Nanomaterials
Teflon
Corn starch polymers
Properties of graphene
Very strong and very light material
Harder than diamond
about 300 times stronger than steel
Transparent
Conducts electricity and heat even better than copper
Stretchable
Extremely flexible (which is unusual for such a strong, tough metal) .
Impermeable to all known substances
Uses of graphene
Due to its strength, graphene is being developed for use in protective clothing, vehicles and buildings
Conductive ink is made by mixing tiny graphene flakes with ink (this enable you to print onto paper and use this print to conduct electricity)
Used in solar cells. These cells need conductive materials that allow light to get through them.
Graphene is a suitable material due to its high conductivity and transparency.
Unfortunately it is not very goof at collecting the electrical current produced inside the solar cell (so further developments need to be made) - use of graphene oxide - less conductive but more transparent and a better collector of charge.
Graphene - has been used in paint to act as a barrier between materials and the corroding effects of oxygen and water.
In the future, vehicles could be made corrosion resistant with such paint.
Electronic companies are investigating the use of graphene in touchscreens - since it is able to transfer electrons at much faster speeds than silicon.
This paired with its flexibility, could lead to foldable televisions or computers, and due to its transparency - could lead to virtual windows.
These materials are being developed for use in mobile technology, biomedicine, composites, material coatings and energy storage.
What is graphene
A very thin two-dimensional material layer of carbon that was discovered and extracted from carbon in 2004
How can be metals be made into a foam
Metals such as aluminium (and sometimes steel or titanium) can be made into a foam by injecting gas into the metal when it is a liquid state.
This creates a foam
Properties of metal foam
The foam is very lightweight
Has high compressive strength
Electrically and thermally conductive
Good sound absorption
A very porous material
It can absorb energy well
Uses of metal foam
Used as soundproofing Used for crash protection in vehicles as it is light enough to be carried in cars without reducing their speed
It is also being developed in the use of body arm, because it is lightweight and strong
Used in filtration due to its porosity.
Currently being developed for use in prosthetics (artificial body parts) for animals
With the aim of creating prosthetics that are lighter and more comfortable for the user
These materials are commonly used in aircraft, car parts, impact absorption and medical implants.
Properties of titanium
High corrosion resistance (even to salt water and chlorine)
High strength-to-density ratio
Strength
Low density
when exposed to the elements it doesn’t go rusty (it can resist the effects of the rain and moisture in the air by reacting with oxygen to produce titanium oxide, which keeps out water and air)
Uses of titanium
Its high strength-to-density to ratio, makes it suitable for use in applications such as knee replacements
Its strength and low density makes it a good choice of material for aircrafts
It is also frequently used as titanium oxide.
In this form it is used as a white pigment in plastic and paint and as a sunscreen in cosmetic products
Commonly used for joint and dental implants as the material does not react with the human body making it hypoallergenic.
Also used in jewellery, watches, aircraft and sports cars due to its high strength to weight ratio.
What other metal can titanium be allowed with
Titanium can be alloyed with other metals such as aluminium and vanadium
Examples of coated metals
Anodised aluminium
Nickel-plated steels
Polymer-coated aluminium
What is anodised aluminium
Anodised aluminium is aluminium with a thick oxide layer created by passing a current through an electrolytic solution
Why does a current pass through an electrolytic solution for a thick oxide layer to be added with aluminium
This process increases resistance to corrosion and wear, and it makes it easier to paint and glue
What is nickel-plated steel
Nickel-plated steel uses the process of electrolysis to add the nickel to a steel object
Advantages of using nickel-plated steel
This allows us to use a strong and relatively cheap material such as steel and coat it in a thin later of more expensive nickel which is corrosion resistant and can add an attractive finish to a product
What is polymer-coated aluminium
Polymer-coated aluminium can be created by dip coating or powder coating the aluminium.
Uses of polymer-coated aluminium
This process is used for products suchas dishwasher racks and tool handles
Describe the two ways the polymer can be coated onto the aluminium
Polymer-coated aluminium can be created by dip coating or powder coating the aluminium.
Polythene is often used in powder form for dip coating, whereby the metal is dipped into a liquid polymer.
Powder coating is where the powder is sprayed on to the metal and then cured in an oven
Products that have been polymer-coated (aluminium) by powder coating are more what than standard products
These products tend to be more expensive than standard ones as they are particularly hardwearing
What is the impact of both processes (dip coating/powder coating) on the product
Both processes create a layer of plastic around the metal which reduces the impact of exposure to air and moisture and provides and attractive and potentially colourful finish to the product
Liquid Crystal Displays abbreviated to
LCDs
What is a liquid crystal display
A liquid crystal display is a laminated material of two layers of glass with a liquid crystal core.
It is a thin flat panel that lets light go through when a voltage is applied, or blocks the light when the voltage is switched off.
Uses of LCDs
LCDs are often used in electronic items such as digital watches and flat-screen televisions, clocks, microwaves, computer monitors, satellite navigation systems
Many LCDs work well by themselves when there is other light around but others need a back light(such as for smartphones, computer monitors and televisions)
Properties of LCSs
These displays have low power consumption, create sharp images, and are compact and flat.
Liquid crystal displays are found in a monochrome or colour display format.
Numbers or letters are displayed when a voltage is applied to create a symbol or image.
What are nanomaterials
Nanomaterials have tiny parts less than 100 nanometres in size
How many metres is a nanometre
A nanometre is one billionth of a metre
1 x 10^-9 of a metre
