Emulsions and gels
Surface Chemistry and Colloids · Chemistry
Study notes
Why does oil separate from water but milk stays mixed? Step 1: Oil and water are immiscible — water molecules attract each other strongly and squeeze oil out. Step 2: Milk contains casein protein which acts as an emulsifier. Step 3: Casein coats each fat droplet; the coated droplets repel each other instead of merging. Step 4: Result: a stable oil-in-water emulsion that doesn't separate for days.