4-Vinylpyridine-divinylbenzene-based anion exchangers were synthesized by suspension polymerization. Diluent mixtures containing a range of cyclohexane to cyclohexanone ratio were employed to dilute monomers at the time of polymerization. The ion exchangers were characterized for porosity, ion exchange capacity and t(1/2) for exchange of (FeCl4)(-) ions adsorbed on resins and those in the surrounding solution. A gradual increase of cyclohexane fraction in the diluents from 0% to 100% resulted in: a gradual increase in pore volume from 0.1 to 1.6 ml/g; shift of pore diameter of major fraction of pores from < 0.01 to > 0.5 mum; and a decrease in breakthrough volume capacity for (FeCl4)(-) from 0.7 to 0.2 meq/ml. The t(1/2) value decreased from 63 to 8 s followed by an increase to 70 s at 0%, 50% and 100% cyclohexane in the diluents, respectively. (C) 2002 Elsevier Science B.V. All rights reserved.