Smart materials + composites

• What triggers a change of colour in thermochromic pigments?

  Hot and cold temperatures
• What are the applications of thermochromic pigments?

  • Fever scan strips for infants
  • Room thermometers
  • Children's cutlery and crockery
  • Novelty goods and colour changing clothing
• What is a characteristic of some thermochromic pigments?

  They have a permanent change
• What does QTC stand for?

  Quantum tunnelling composite
• What is unique about QTC as a material?

  It is both an insulator and a semi-conductor
• What happens to QTC when pressure is applied?

  It becomes a conductor allowing electrical signals
• What are the uses of Quantum tunnelling composite (QTC)?

  • Buttons on cameras
  • Video game controllers
• What is polymorph?

  A thermoforming plastic that softens at low temperature
• What is the melting point of polymorph?

  62 degrees C
• For what purpose is polymorph commonly used?

  Modelling, especially ergonomic testing
• How do photochromic particles react to ultraviolet light?

  They change within lenses
• What is a common use of photochromic particles?

  Prescription glasses that turn into sunglasses
• What is a drawback of photochromic lenses?

  They can take time to change
• What happens to photochromic glasses over time?

  They lose the ability to change back
• How do photochromic pigments react to UV light?

  They only work in strong UV light
• What are the main uses of photochromic pigments?

  • Novelty goods
  • Colour changing paints
• What are electroluminescent materials?

  Materials that glow when current is applied
• In what forms can electroluminescent materials come?

  Wire or flexible film form
• What are the applications of electroluminescent materials?

  • Car dashboard LCD screens
  • Displays
  • Signage
  • Fashion
• What are the advantages of electroluminescent materials?

  Low power consumption and no heat generation
• What is a shape memory alloy (SMA)?

  An alloy that returns to its original shape
• What is Nitinol?

  An SMA of nickel and titanium
• What temperature is required to set Nitinol into shape?

  A high temperature of around 540 degrees
• What happens to Nitinol when it is reheated?

  It returns to its pre-set shape
• What are the uses of shape memory alloys like Nitinol?

  • Glasses that return to original form
  • Surgical stents for arteries
• What are composites made of?

  Mixtures of different materials
• What are the types of reinforced plastic?

  • Glass reinforced plastic (Fibre glass) GRP
  • Carbon fibre reinforced plastic (CFRP)
• What type of resins are used in reinforced plastics?

  Thermosetting resins
• What do thermosetting resins produce?

  Volatile organic compounds (VOCs)
• What is the purpose of adding a catalyst to resin?

  To make it harden or 'cure'
• What do VOCs stand for?

  Volatile organic compounds
• How can VOCs affect health?

  They are bad for health if touched or inhaled
• What functionalities can technical textiles provide?

  • Weatherproofing (e.g., Gore-Tex)
  • Strengthening
  • Adding conductivity and insulation
• What is Gore-Tex known for?

  Being waterproof yet breathable
• How many holes does Gore-Tex have per cm squared?

  150 million holes
• What does the structure of Gore-Tex allow?

  Droplets are too big to pass through
• What are aramids?

  • Tough fibres made from modified polyamide
  • Offer cut and tear resistance
  • Flame proofing and thermal insulation
  • High strength and hard wearing finish
• Name two types of aramid.

  Nomex and Kevlar
• What is Nomex commonly used for?

  Firefighters' uniforms and F1 drivers' overalls
• What happens to Nomex when exposed to flame?

  It burns but stops when heat is removed