What is the name of the process for the separation of colloidal particles from those of crystalloids called?
This property of animal membranes is utilized for the purification of sols. The process involved is called dialysis. It may be defined as follows. The process of separating the impurity particles of true solution dimensions (crystalloids) from an impure sol by means of diffusion through a suitable membrane such as parchment paper or cellophane membrane is called dialysis. The apparatus used in this method is called dialyzer. It consists of a bag made of parchment or cellophane. The bag is filled with the impure sol to be purified and is suspended in a tank through which pure water is circulated. The impurities of electrolytes present in the sol diffuse out of the bag leaving behind pure sol in the bag.