Is there any kind of colloid that the size of the solute molecule is smaller than the size of the solvent molecule. If so, how we can separate them with a hydration layer?
Of course there, for example the crude petroleum is colloidal (water in petroleum) which you know the water size (solute) is less small than the size of organic (solvent). There are many methods for separation including addition of surfactants, heating, distillation, and so on.