Lipid
4.3 乳状液与乳化剂
Emulsions and emulsifier
If you shake
together oil and
water, you get
an emulsion.
Surface phenomenon 1，Dispersion
2，Oil and water(surface intension)
3，Air and water(surface intension)
4，Surfactants （emulsifier, ice cream ）
5，liquid and solid
1. Dispersions 分散相（非连续相），以液滴或液晶的形式出现分散介质（连续相）
?Example
?水包油的乳状液 O/W:稀奶油
?油包水的乳状液 W/O：奶油和人造奶油
Characterization of Dispersions
Different states of the phases
气雾剂
Size of dispersed particles
浑浊度/不透明
Size effects of disperse phase - Visual appearance
青白色
Chemistry-Colloidal gold Suspensions of gold nanoparticles of various sizes. The size difference causes the difference in colors.
2. Oil-water
interface and emulsion stability Phase boundary Interfacial Tension
界（表）面Gibbs自由能
界（表）面能
界（表）面张力
The interfacial tension of many binary systems lies between the surface tensions of the pure components at the same temperature. But when the liquids are mutually soluble, the tension is small.
Surface Tension surface area
Which shape?
Making an Emulsion
Creating Surface Area
?δW=γ δA
?γ- 界面张力
3. Air-Water