PHC320H1 Lecture Notes - Lecture 10: Surface Tension, Emulsion, Surfactant

• School: UTSG
• Department: Pharmaceutical Chemical Engineering and Applied Chemistry
• Course: PHC320H1
• Professor: Shirley Wu

Document Summary

We can have w/o and o/w emulsions. The most stable configuration in the system, is when the two phases are well-separated and they have minimal contact. But, we want to have a tiny droplet of oil distributed in water or vice versa. This makes an unfavorable situation due to large interfacial area and large interfacial energy. And, if we don"t do anything drastic, the system will separate into two phases. The drastic agent is the emulsifying agent that will make this unfavorable situation favorable. And, there are a number of properties that are desirable to be made when we chose the optimum emulsifying agent. We want the emulsifying agent to decrease the interfacial tension between the air and water phase to make the situation less unfavorable thermodynamically. We want the added emulsifying agent to be adsorbed around the dispersed particles. We want the particles to behave like a film (mechanically strong armor) that will protect these particles from coalescence.