From microspheres to monoliths: Synthesis of porous supports with tailored properties by radiation polymerization

Abstract

Advanced functional materials, both in shape of beads and monoliths, are in high demand for a variety of applications ranging from catalysis, chromatography, diagnostics, sensors to combinatorial chemistry. Here we report the synthesis of functional supports of different size and shape by radiation co-polymerization in organic solvents using diethylene glycol dimethacrylate (DEGDMA) and glycidylmethacrylate (GMA) as co-monomers. With the increase in the GMA content, the particle diameter increases from 0.9 to about 3 μm, while the yield decreases from 80% to 50%. The usefulness of the microspheres for immobilization was tested with histidine and lysosyme. Monoliths were prepared in situ as chromatographic columns. Our results showed that when a 30% monomer solution was irradiated, a 100% conversion of the monomer was obtainable with doses higher than 15 kGy. We showed the effect of dose and dose rate as well as the irradiation temperature on the pore size of the monoliths and the flux. The effect of such different solvents as tetrahydrofuran, ethylpropionate, acetone, methanol, ethanol, propanol and butanol is also discussed. Our results showed that radiation synthesis of porous polymer supports with epoxy functionality is a viable alternative to either thermally initiated or photo polymerization.