Step-growth grafted anion exchangers with hyperbranched polyglycerol modification for ion chromatography.

Herein, we report a step-growth approach to constructing polyelectrolyte-grafted stationary phases for ion chromatography (IC). Linear polyelectrolytes were covalently immobilized onto diol-functionalized substrate particles via cycled di-epoxide-mediated grafting, building up controllable functional layers. The materials can be packed and employed directly for IC, or further subjected to surface-initiated glycidol polymerization to introduce a hyperbranched polyglycerol overlayer, thereby improving stationary phase hydrophilicity. The modifications were verified by scanning electron microscopy, elemental analysis, Fourier-transform infrared spectroscopy, and N2 adsorption-desorption analysis. The correlations between chromatographic properties and synthetic variables were examined. The proposed anion exchangers were further evaluated for the separation of common inorganic anions, polarizable anions, organic acids, and nucleotides under suppressed IC conditions.