Monosize, 1.6 μm, magnetic beads of poly（glycidyl methacrylate） [M-poly（GMA）], were prepared by dispersion polymerization in the presence of Fe3O4 nano-powder. Monosize M-poly（GMA） beads were characterized by s...Monosize, 1.6 μm, magnetic beads of poly（glycidyl methacrylate） [M-poly（GMA）], were prepared by dispersion polymerization in the presence of Fe3O4 nano-powder. Monosize M-poly（GMA） beads were characterized by swelling tests, density measurements, electron spin resonance （ESR）, vibrating sample magnetometer （VSM） and scanning electron microscopy （SEM）. The characteristic functional groups of M-poly（GMA） beads were analyzed by Fourier transform infrared spectrometer （FTIR）. The M-poly（GMA） beads are highly uniform in size and have a spherical shape and non-porous structure. Polydispersity index （PDI） of M-poly（GMA） beads was calculated to be around 1.008. The hydrated density of the M-poly（GMA） beads measured at 25 ℃ was 1.14 g/cm^3. The content of oxirane groups on the surface of the M-poly（GMA） sample was found to be 3.46 mmol/g by using perchloric acid titration. The specific surface area of the M-poly（GMA） beads was determined to be 3.2 m^2/g. The equilibrium swelling ratio was 52%. The volume fraction of magnetite nanopowder in the M-poly（GMA） beads was found to be 4.5%. The g factor, that can be considered as a quantity characteristic of the molecules in which the unpaired electrons are located, was found to be 2.28 for M-poly（GMA）. The external magnetic field at resonance was calculated to be 2055 Gs which was found sufficient to excite all of the dipole moments present in 1.0 g of M-poly（GMA） sample.展开更多
A novel reactive resin as active support was synthesized by an improved method based on seed swelling and surface coating polymerization. The resin is monosized beads with inner nucleus of cross-linked polymer and sur...A novel reactive resin as active support was synthesized by an improved method based on seed swelling and surface coating polymerization. The resin is monosized beads with inner nucleus of cross-linked polymer and surface layer of copolymer containing epoxy groups. The physico-chemical structures of beads were characterized.展开更多
文摘Monosize, 1.6 μm, magnetic beads of poly（glycidyl methacrylate） [M-poly（GMA）], were prepared by dispersion polymerization in the presence of Fe3O4 nano-powder. Monosize M-poly（GMA） beads were characterized by swelling tests, density measurements, electron spin resonance （ESR）, vibrating sample magnetometer （VSM） and scanning electron microscopy （SEM）. The characteristic functional groups of M-poly（GMA） beads were analyzed by Fourier transform infrared spectrometer （FTIR）. The M-poly（GMA） beads are highly uniform in size and have a spherical shape and non-porous structure. Polydispersity index （PDI） of M-poly（GMA） beads was calculated to be around 1.008. The hydrated density of the M-poly（GMA） beads measured at 25 ℃ was 1.14 g/cm^3. The content of oxirane groups on the surface of the M-poly（GMA） sample was found to be 3.46 mmol/g by using perchloric acid titration. The specific surface area of the M-poly（GMA） beads was determined to be 3.2 m^2/g. The equilibrium swelling ratio was 52%. The volume fraction of magnetite nanopowder in the M-poly（GMA） beads was found to be 4.5%. The g factor, that can be considered as a quantity characteristic of the molecules in which the unpaired electrons are located, was found to be 2.28 for M-poly（GMA）. The external magnetic field at resonance was calculated to be 2055 Gs which was found sufficient to excite all of the dipole moments present in 1.0 g of M-poly（GMA） sample.
基金supported by the National Natural Science Foundation of China(Grant No.29635010).
文摘A novel reactive resin as active support was synthesized by an improved method based on seed swelling and surface coating polymerization. The resin is monosized beads with inner nucleus of cross-linked polymer and surface layer of copolymer containing epoxy groups. The physico-chemical structures of beads were characterized.
