dialysis

The process of separating a colloidalsol from a colloid-free solution by a membrane permeable to all components of the system except the colloidal ones, and allowing the exchange of the components of small molar mass to proceed for a certain time.
Source:
PAC, 1972, 31, 577 (Manual of Symbols and Terminology for Physicochemical Quantities and Units, Appendix II: Definitions, Terminology and Symbols in Colloid and Surface Chemistry) on page 608