辐射乳液聚合制备聚苯乙烯/四氧化三钴中空复合材料

Hollow Co3O4 nanoparticles/polystyrene microspheres prepared by emulsion polymerization under irradiation

本工作使用的四氧化三钴纳米颗粒经由水热法合成,使用油酸对颗粒表面进行修饰。采用苯乙烯(St)、十二烷基硫酸钠(SDS)和十六醇(CA)配成的乳液体系,添加四氧化三钴纳米颗粒(OA-NP),利用γ射线辐照引发单体聚合,制备出具有中空结构的聚合物-纳米颗粒复合物。复合物产物的电镜照片显示改变SDS、OA-NP的用量可控制样品的形貌及尺寸。苯乙烯单体聚合动力学研究发现,OA-NP对聚合有阻聚作用。在聚合早期,纳米复合物球壳上出现"大孔"结构,随着聚合时间增加"大孔"有逐渐闭合的趋势。据此,推测了复合物中空结构的可能形成机理。四氧化三钴纳米颗粒与复合物的磁性能比较表明,聚合物包覆可对四氧化三钴纳米颗粒的软磁特性产生影响。

Polymer-nanoparticles composites with hollow structure were prepared by emulsion polymerization with Co3O4 nanoparticles （OA-NP） added into emulsion system containing styrene （St）, sodium dodecyl sulfate （SDS） and cetyl alcohol （CA） under irradiation using y-rays. Co3O4 nanoparticles were synthesized by hydrothermal method at first, and then modified with oleic acid （OA）. The influence factors such as dosage of OA-NP and SDS on morphology and size distribution of hollow spheres were thoroughly studied. OA-NP was proved to inhibit the polymerization of St in the kinetic studies. It was found that pores occurred on hollow spheres＇ shell at the first stage of reaction, and then the perfect shells formed gradually with polymerized time. The mechanism for the hollow spheres formation was proposed based on the obtained results. The soft magnetic properties of C0304 nanoparticles were influenced directly by polystyrene.