Described is a method to prepare stable emulsions wherein colloidal particles are used to stabilize the liquid interface, said particles being initially inherently partially lyophobic particles or partially lyophobized particles having mean particle sizes from 1 nm to 20 µm. In one aspect, the partially lyophobized particles are prepared in-situ by treating initially hydrophilic particles with amphiphilic molecules of specific solubility in the liquid phase of the suspension.