Hyperbranched anion exchangers prepared from thiol-ene modified polymeric substrates for suppressed ion chromatography

The covalent modification of polymeric particles has been a challenge due to their chemical inertness. Herein we describe a facile and neat method via thiol-ene reaction to immobilize cysteamine/cysteine onto allylmethacrylate-divinylbenzene (AMA-DVB) and ethylvinylbenzene-divinylbenzene (EVB-DVB). The introduced functionalities were verified by elementary analysis and scanning electron microscope coupled with energy dispersive spectroscopy . This modification enabled the further grafting of hyperbranched condensation polymers (HBCPs), which converted the particles into anion exchangers. The anion exchangers demonstrated good separation with carbonate/bicarbonate eluents and hydroxide eluents for suppressed anion exchange chromatography . In the case of a 3-layered anion exchanger, simultaneous separation of nine model anions was achieved by isocratic elution in 17 min with efficiencies up to 16,100 plates m −1 . High stability and dependable durability was exhibited in long-term tests.