Study On Preparation Of P(St/MAA)/Fe₃O₄ Applied To Immobilize Enzyme By Dispersion Polymerization

As a immobilized enzyme composition part, the structure and the performance of carrier material had the huge effect on the performance of immobilized enzyme .As a result of the carrier material's importance, since the immobilized enzyme technology emerged , many scholars continuously devoted themselves to the carrier research, Until now, along with the science and technology development, the immobilized enzyme carrier material also developed from the natural polymer material to the organic polymer material, inorganic material as well as current compound material such as magnetic polymer microsphere and so on. For magnetic polymer microsphere had not only polymer microsphere's multitudinous characteristics but magnetism responsiveness, it was allowed conveniently to separate under the sur-magnetic field and it could be applied to the field of immobilized enzyme, therefore which had gradually aroused people's enormous interest in the immobilization enzyme on magnetic polymer microsphere.At present, there were many ways to prepare magnetic polymer microsphere, among which, the magnetic polymer microsphere was quite suitable to be the carrier of the biological enzyme by way of dispersion polymerization. Meanwhile, dispersion polymerization was an effective way of bringing functional groups to the surface of the polymer..So the article goal was to prepare one kind of micron level mono-dispersity functional magnetic polymer microsphere, which enabled itself to take on the carrier of the biological enzyme.Fe₃O₄ was used to be the core material of the microspheres, which was prepared by co-precipitation method. Magnetic polymer microspheres were prepared through polymer encapsulation of small Fe₃O₄ particles, using dispersion polymerization of styrene/MAA in aqueous ethanol medium. Poly(N-vinylpyrrolidone)(PVP) and 2,2'azo-isobutyrodinitrile(AIBN) were utilized as steric stabilizer and initiator, respectively. The effect of reaction temperature, ways of feeding raw material, dispersion medium, stabilizer, initiator, monomer and ferrofluid on performance of the microspheres was investigated. Scanning electron microscope(SEM), transmission electron microscope(TEM), VSM, magnetic balance and Fourier inversetransformation infrared spectrum were used to characterize the magnetic polymer microspheres. Meanwhile, in order to enhance the magnetic performance of the microspheres, the pre-treatment of the ferrofluid was also studied. Mechanism of dispersion polymerization in the presence of ferrofluid was also discussed and the microspheres used to immobilize enzyme was also studied.The original works done were as follows. (1). Function monomer MAA had a big influence on the dispersion polymerization system. In order to obtain steady dispersion polymerization system, the medium polarity must be adjusted. (2).In order to prevent the gelatin in the reaction, a special way of calefaction to the polymerization system was adopted. (3). Microspheres with average size 0.92 u m and monodispersity 0.012 was synthesized, which contained more than 18 percent magnetic material JS.Slemu.g"1 saturatio magnetization and 0.040mmol/g superficial carboxylic acid content. (4).Not only the introduction of the superficial carboxylic but EDC. HC1 could enhance activity and immobilization ratio. (5).Dispersion polymerization in the presence of ferrofluid was made up of two part. One was a kind of polymerization which occurred on the surface of ferrofluid, and the other was common dispersion polymerization. Study showed that the latter dominated...