1. © Oxford University Press 2011 IC1.26.3 Emulsions Emulsions

2. © Oxford University Press 2011 IC1.26.3 Emulsions

3. © Oxford University Press 2011 IC1.26.3 Emulsions Vegetable oils and water don’t mix together well … The oil floats on the water

4. © Oxford University Press 2011 IC1.26.3 Emulsions Vegetable oil molecules have long hydrocarbon chains

5. © Oxford University Press 2011 IC1.26.3 Emulsions They cannot interact with small water molecules

6. © Oxford University Press 2011 IC1.26.3 Emulsions Questions  What happens when you mix oil and water?  Why don’t oil and water mix well?

7. © Oxford University Press 2011 IC1.26.3 Emulsions If you add an emulsifier to oil and water and mix well, the oil and water no longer separate out. An emulsion forms.

8. © Oxford University Press 2011 IC1.26.3 Emulsions One end interacts well with water molecules (hydrophilic end) the other end interacts well with oil molecules (hydrophobic end)

9. © Oxford University Press 2011 IC1.26.3 Emulsions Emulsifier molecules coat the surface of oil droplets. These coatings keep the oil droplets evenly dispersed in the water

10. © Oxford University Press 2011 IC1.26.3 Emulsions Questions  What type of molecules do emulsifiers have?  How do emulsifiers stop oil and water separating out?