Preparation of cross-linked copolymer microspheres 4VP/St and cobalt tetraphenylporphyrins supported on it

The cross-linked microspheres 4VP/St made of 4-vinylpyridine (4VP) and styrene(St) were prepared with suspension copolymerization method using ethyl glycol dimethacylate (EGDMA) as cross-linker and polyvinyl alcohol (PVA) as disperser. The cobalt tetraphenylporphyrins (CoPs) were immobilized on 4VP/St microspheres via the axial coordination reaction between CoPs and the pyridine groups of 4VP/St microspheres, resulting in the functional microspheres CoP-4VP/St. The chemical structure of 4VP/St and CoP-4VP/St were characterized with infrared spectrum and their morphologies were observed with the scanning electron microscope. The experimental results show that via controlling the various reaction conditions of the suspension copolymerization, the 4VP/St microspheres with excellent sphericity and narrow particle diameter distribution can be gained. In addition, CoPs are successfully immobilized on 4VP/St microspheres by means of Co-N bonds, on which the immobilized content of CoPs goes up to 10.7-17.5 μmol/g.