SYNTHESIS OF MONODISPERSE HOLLOW POLYMER MICROSPHERES WITH FUNCTIONAL GROUPS BY DISTILLATION PRECIPITATION POLYMERIZATION

Monodisperse hollow polymer microspheres having various functional groups on the shell-layer, such as carboxylic acid, pyridyl and amide, were prepared by two-stage distillation precipitation polymerization in neat acetonitrile in the absence of any stabilizer or additive, during which monodisperse poly（methacrylic acid） （PMAA） afforded from the first-stage polymerization was utilized as the seeds for the second-stage polymerization. The shell layer with different functional groups was formed during the second-stage copolymerization of either divinylbenzene （DVB） or ethyleneglycol dimethacrylate （EGDMA） as crosslinker and the functional comonomers, in which the hydrogen-bonding interaction between the carboxylic acid group of PMAA core and the functional groups of the corresponding comonomers, including carboxylic acid, amide and pyridyl, played an essential role for the formation of monodisperse core-shell functional microspheres. The hollow polymer microspheres were then developed after the subsequent removal of PMAA cores by dissolution in ethanol under basic condition. Transmission electron microscopy （TEM） and scanning electron microscopy （SEM） were used to determine the morphology of the resultant PMAA core, functional core-shell microspheres and the corresponding hollow polymer microspheres with different functional groups. FT-IR spectra confirmed the successful incorporation of the various functional groups on the shell layer of the hollow polymer microspheres.

Preparation of slightly crosslinked monodisperse poly(maleic anhydride-cyclohexyl vinyl ether-divinylbenzene)functional microspheres with anhydride groups via precipitation polymerization

Slightly crosslinked monodisperse poly（maleic anhydride-cyclohexyl vinyl ether-divinylbenzene） （MA-CHVE-DVB） microspheres were prepared via precipitation polymerization while using 2,2- azobisisobutyronitrile as an initiator in a mixture of methyl ethyl ketone and n-heptane without any stabilizer. The number-average diameter of the resultant poly（MA-CHVE-DVB） microspheres ranged from 0.478 to 1.386 μm with a polydispersity index of 1.00 to 1.02 that depended on the feed ratios of the MA/CHVE/DVB monomers. The introduction of one electron donor monomer cyclohexyl vinyl ether strongly affected the yield, size, and morphology of these slightly crosslinked microspheres. Quinoline- type chelating resins were obtained after combining the poly（MA-CHVE-DVB） with 8-hydroxyquinoline; the adsorption properties of these materials were measured through their ability to remove Cu^2＋ ions from water. The poly（MA-CHVE-DVB） microspheres with low degrees of crosslinking provided more effective functional groups and therefore better ion removal capabilities. These slightly crosslinked microspheres may have applications in water treatment as well as in sensing and drug delivery.

MAGNETIC POLYMER MICROSPHERE STABILIZED GOLD NANOCOLLOIDS AS A FACILELY RECOVERABLE CATALYST

Magnetically responsive hierarchical magnetite/silica/poly（ethyleneglycol dimethacrylate-co-4-vinylpyridine） （Fe3O4/SiO2/P（EGDMA-co-VPy）） tri-layer microspheres were used as stabilizers for gold metallic nanoeolloids as a facilely recoverable catalyst with the reduction of 4-nitrophenol to 4-aminophenol as a model reaction. The magnetic microsphere stabilized gold metallic nanocolloids were prepared by in situ reduction of gold chloride trihydrate with borohydride as reductant via the stabilization effect of the pyridyl groups to gold nanoparticles on the surface of the outer shell-layer of the inorganic/polymer tri-layer microspheres.

Immobilization of Antibodies on Magnetic Carbonaceous Microspheres for Selective Enrichment of Lysine-acetylated Proteins and Peptides

Lysine acetylation is a dynamic and reversible modification, which has been proved to be a key posttransla- tional modification in cellular regulation. However, the low amounts of the acetylated proteins could hardly be de- tected before enrichment. In this study, for the first time, antibody-immobilized magnetic carbonaceous micro- spheres were developed for selective enrichment of acetylated proteins and peptides. At first, standard proteins composed of acetylated bovine serum albumin, myoglobin, a-casein and ovalbumin were used as model proteins to verify the enrichment efficiency. Then, the synthesized peptide was employed to confirm the selectivity of the method. Besides, the antibody-immobilized magnetic particles were successfully applied to analyze mouse mito- chondrial proteins. After database search, 29 acetylated sites in 26 proteins were identified.