Adsorption techniques: dialysis sorbents and membranes.

Adsorption is based on the attraction between the sorbent and the solute through hydrophobic interactions, ionic or electrostatic forces, hydrogen bonding or van der Waals forces. Adsorption is the adherence of molecules by the above-mentioned forces not only to the surface of the membrane but also to its interior. Since polymethylmethacrylate membranes have a much higher inside effective exchange surface than polysulfone membranes, these membranes are able to ensure a high level of adsorption, and therefore reduce the concentration of high-molecular-weight molecules and protein-bound uremic toxins.