SYNTHESIS AND CHARACTERIZATION OF SILICA-BASED ALIPHATIC ION-EXCHANGERS

The chemical literature describing preparation of aliphatic ion exchan gers is limited, and although such phases are available commercially, the synthetic schemes are proprietary. The course of our research requ ired the preparation of silica-based aliphatic cation and anion exchan gers for which the desired base silica and/or ligand properties were n ot commercially available. We developed synthetic schemes to prepare s ilica-based aliphatic sulfonic acid, carboxylic acid and quaternary am monium ion-exchange phases with active exchange capacities of 0.2-0.9 mu mol/m(2). Multiple techniques were used to characterize the interme diate and final phases produced in the syntheses, including Fourier tr ansform diffuse reflectance infrared spectroscopy, spot tests, element al analysis, acid-base titration and elution analysis.