Miniemulsions via in situ Surfactant Generation

The preparation and stabilisation of miniemulsions using in situ generated surfactants is described. Neutralising a water‐soluble base with an oil‐soluble long‐chain acid instantaneously generates in situ surfactants at the oil/water interface, resulting in a rapid homogenisation/polymerisation process. It was found that droplet sizes decreased with surfactant concentration and solid content and that in situ generated potassium stearate is not capable of simultaneously serving as a surfactant and costabiliser. However, the presence of stearic acid delays the rate of ripening. A number of in situ surfactants were prepared with different acids and bases. It was found that the droplet size decreased with the hydrated radius of the counterions. magnified image