What are quantum dots?
Small semiconductor particles that can be excited with light. They then emit light a at particular wavelength due to their size.
Some plant leaves and petals are very hydrophobic and self cleaning. This is due to nanostructured hydrophobic surfaces. Any dirt binds to water droplets rather than the surface. Currently used on paints, roof tiles, clothes and glass.
How do we study nanosized molecules? (5)
- Atomic Force Microscopy
- Electron Microscopy
- X-ray crystallography
- Small Angle scattering
- Reflection methods eg neutrons.
A chemical compound possessing both hydrophilic (water-loving, polar) and lipophilic (fat-loving) properties.
Hydro (water) phobic (hating) indicates a repulsion between the hydrophobic molecule and water but this is not true.
Hating is the wrong word – it insinuates that the molecule repels water. It does not, it is simply less attracted to water than water is to itself.
Why would the interface of a demonstration of the hydrophobic effect be very smooth.
As this means the molecules would be at the lowest possible energy state, something which is strived for.
What are micelles?
Spherical structures with hydrophobic tails pointing inwards.
What is a surfactant?
A substance which tends to reduce the surface tension of a liquid in which it is dissolved.
How many amino-acids does it take to complete a twist in an alpha helix?
What number is the nanoscale?
What is the wavelength range of visible light?
Define the click reaction (click chemistry). (6)
"Click Chemistry" is a term that was introduced by K. B. Sharpless in 2001 to describe reactions that are:
- High yielding
- Wide in scope
- Create only byproducts that can be removed without chromatography
- Simple to perform
- Can be conducted in easily removable or benign solvents.