Week 6

EES Team 6 (BP Water and Oil Sparation) reaserched the different methods of separating water and oil.

"The first one we discovered was natural separation where we’d place water into a crystal clear container and add food colouring to make the actual separation itself more obvious. We’d then pour oil into it and initially it’ll probably drop to the bottom because of the force and action of falling but eventually it will rise towards the very top. Water and oil don’t mix together because they’re very chemically different as water is polar (each molecule has parts with miniscule positive and negative electric charges) and oil is nonpolar so inevitably and obviously, it won’t mix immensely with polar liquids. The density of oil is also lower than water which is why it immediately and naturally rises to the top.

The second one was separating an emulsion which is a mixture of oil and water in the form of tiny droplets and it would still start off with having a container filled with oil and water except this time, we’d vigorously shake it. This would cause the mixture of the two to become cloudy so the differences won’t be as obvious. We would have to let it sit undisturbed so that the oil would gradually become a vaguely separate layer or an alternative to waiting would be to add salt because as it dissolves within the water - it makes it more polar and less likely to end up associating with the oil.

After this we found out what emulsifiers and de-emulsifiers were. We learnt that an emulsifier is a substance that stabilises an emulsion by increasing its kinetic stability. They are compounds that usually have a polar/hydrophilic (water-soluble) part and a non-polar/hydrophobic part and because of this, emulsifiers tend to have either more or less solubility either in water or oil. Emulsifiers that are more soluble in water (and conversely, less soluble in oil) will generally form oil-in-water emulsions, while emulsifiers that are more soluble in oil will form water-in-oil emulsions"