PHC320H1 Lecture Notes - Lecture 25: Surface Tension, Emulsion, Contact Angle

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

Document Summary

Second type is multimolecular film which consist of lyophilic particles which accumulate around emulsified droplets in many layers and even though no decrease in interfacial tension they still provide particle with armor so they are safe. We just used the same equation and changed to a, b this lets us choose proper material for solid particles to serve as a protective emulsifying agent rearrange this equation to find costheta. Stability is characterized by absence of coalescence so we don"t want emulsified particles to coaslesce then we talk about breaking of emulsion which si the end of pharmaceutical value. Viscosity viscosity should be high enough to retard not only creaming or sedimentation by high viscosity since all kinds of movements inside system, rate of collisions will be reduced by increased viscosity, so look for appropriate thickening agent. % ratio, in that case the type of emulsion will be determined by the affinity of the emulsifying agent of oil or water phases.