04 May In the Lab – Making nylon and using a Leslie Cube
The making of Nylon
Year 11 Chemistry students took a short break from working on IGCSE past papers to make nylon on Monday 30 April. They used two reactants – an aqueous solution of a chemical called a di-amine and an organic solution of a chemical called a di-acid. They carefully poured the organic solution on top of the aqueous solution in a small beaker, so that the di-acid was lying on top and not mixing with the di-amine. At the interface between the two solutions, a greyish film of nylon formed and the students picked up a little of this with some tweezers. They lifted it slowly and gently from the beaker, as a thread of nylon. There are records set for the amount of nylon made in this way and Suki was keen to try to break the world record. However, as a double lesson wasn’t quite long enough to break the record, after using up the reactants in our small beakers we got back to more past paper practice!
Nylon was first developed and made in the 1930s at a time when relations between Japan and the USA were not great and Japan was refusing to supply America with silk. Scientists from two large cities on opposite sides of the Atlantic Ocean collaborated to synthesise nylon. What 2 cities do you think these were? Get your answers to Mrs Lobo-Clarke or Mr Bennett please, if you want to earn a positive referral.
Thermal radiation using a Leslie Cube
Heat can travel from areas of higher temperature to areas of lower temperature by means of conduction (in solids), convection (in liquids and gases) and by radiation (which doesn’t require any solids, liquids or gases.) John Leslie was a Scottish mathematician and physicist who demonstrated that shiny, smooth surfaces do not radiate as much heat energy as dark, rough, matt surfaces. Hot water is poured into a metal cube that has the 4 vertical sides painted in different colours.
Year 10 used ordinary liquid-in-glass thermometers to show this effect. In 2 minutes the temperature of the thermometer near the matt black surface had risen by 7oC, whereas the one held at the same distance from the shiny, smooth silver surface had only risen by 3oC. We could actually clearly feel more heat coming off from the black surface, just by holding our hands near it.
There is a small cube-shaped satellite that has been orbiting Earth for the last 5 years that also had different surfaces on the different sides; it’s an ongoing experiment into how different surfaces absorb heat radiation (from the Sun) differently. The name of the satellite is FUNcube-1. Quick question: What was the name of the first ever artificial satellite to orbit the Earth? Get your answers to Mrs Lobo-Clarke or Mr Bennett please, if you want to earn a positive referral.