BASE STABLE AND COMPOSITE CERAMIC SUPPORTS FOR HPLC

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The objectives of this collaborative continuation proposal are to develop a multifaceted family of supports based on highly porous (50%), megaporous and non-porous microspheres of zirconium dioxide to be used for both analytical and preparative scale protein chromatography, in fluidized bed separators and for immobilized enzyme and cell reactors. The overall goal of this work is to eliminate the major problems of silica-based supports by replacing SiO/2 with ZrO/2 and to take advantage of the unique Lewis acid surface chemistry as well as the distinct physical properties of zirconia such as its extreme chemical, thermal, physical stability, and high bulk density (3.3 g/cc). Porous, surface-modified, high performance zirconia particles with >400 angstroms pores, 50 micro- porous particles for fluidization, megaporous particles (>1,000 angstroms pores), magnetic, and non-porous particles will be made and characterized by nitrogen adsorption/desorption, porosimetry, solid state NMR and FTIR methods. Investigation of Lewis base-modified (hydroxide, phosphate, fluoride, catechol, citrate), reversed phase (polybutadiene-coated PBD), dextran- coated (steric exclusion, hydrophobic interaction, or ion exchange), polyethyleneimine (PEI) coated (anion exchange), affinity (thiophilic, reactive dye, concanavalin A-, protein A-adsorbed) supports, all begun on the previous grant will be continued. Also proposed is evaluation of porous particles coated with new polymers (polystyrene, homopolymers of amino acids, acrylates, polyakylglycols), polysaccharide-based chiral separations, metal and metal oxide cluster-impregnated zirconia supports useful for a variety of separations such as therapeutic peptides, glycoproteins, nucleosides and other important biomolecules. Non-porous zirconia particles coated with PEI, PBD, or other polymers will be evaluated for very rapid protein separations. Particles optimized for use in fluidized bed separators will be investigated for capture of immunoglobulin and recombinant proteins of therapeutic interest for rapid purification from contaminating lipopolysaccharide and nucleic acids. Previous work on protein-adsorbed zirconia will be extended to investigate novel fluidizable porous ZrO/2 supports for enzyme immobilization and immobilization of bacteria as catalysts.