Ion Exchangers

Ion exchanger resins are insoluble polymeric structures containing mobile ions capable of exchanging with equivalent amounts of ions in the surrounding medium. Cation exchangers will exchange only cations, whereas anion exchangers will exchange only anions. In contrast to ion exchange resins, polymeric adsorbents are truly non-ionic but have a moderately polar behaviour and adsorb non-stochiometrically anions, cations as well as non charged compounds.

Gel-type and macroreticular porous ion exchange resins are based on spherical, cross-linked polystyrene or are made of polyacrylate ester beads. These polymers are cross-linked with divinylbenzene, a poly-functional monomer to give thermal stability. They are free from any plasticizers and the release of soluble, non-desired contaminants in solution is eliminated. They are used in ion exchange batch mode and in chromatography. Merck’s ion exchangers show excellent protein binding capacities at high flow rates and offer advantageous features for many production processes.