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将共沉淀法所得纳米OA-Fe3O4(油酸改性Fe3O4)分散于不同介质中形成磁流体作为芯材,以PMMA(聚甲基丙烯酸甲酯)作为壁材,采用溶剂蒸发法制备磁性微胶囊。对不同芯材及乳化剂进行筛选;考察乳化剂用量、m(芯材)∶m(壁材)及乳化转速对微胶囊制备的影响。通过XRD、FTIR、TEM、SEM、光学显微镜、VSM(振动样品磁强计)对纳米OA-Fe3O4和磁性微胶囊的有效成分、形貌、热性能、磁性能进行分析表征。结果表明,共沉淀法制备的纳米颗粒有效成分为Fe3O4,且可形成稳定磁流体。OA-Fe3O4粒径在3～15 nm,比饱和磁化强度为43.3 emu/g,具有顺磁性。以分散在n-C16H34的OA-Fe3O4磁流体为芯材,w〔SDS(十二烷基硫酸钠)〕=2%的水溶液为乳化剂,m(芯材)∶m(壁材)=5∶1,乳化转速800 r/min条件下可制得外形规整,壁厚1～2μm,且粒径集中于(10±2)μm的磁性微胶囊。该胶囊比饱和磁化强度为36.9 emu/g,具有良好的磁响应性。
The co-precipitation method obtained nano-OA-Fe3O4 (oleic acid-modified Fe3O4) dispersed in different media to form a magnetic fluid as a core material to PMMA (polymethyl methacrylate) as a wall material, the use of solvent evaporation magnetic microcapsules . The different core materials and emulsifiers were screened. The effects of emulsifier dosage, m (core material): m (wall material) and emulsifying speed on the preparation of microcapsules were investigated. The active components, morphology, thermal properties and magnetic properties of nano-sized OA-Fe3O4 and magnetic microcapsules were characterized by XRD, FTIR, TEM, SEM, optical microscope and VSM. The results show that the active component of nanoparticles prepared by coprecipitation method is Fe3O4, and can form a stable magnetic fluid. OA-Fe3O4 particle size in the 3 ~ 15 nm, than the saturation magnetization of 43.3 emu / g, with paramagnetic. Using an OA-Fe3O4 magnetic fluid dispersed in n-C16H34 as a core material and an aqueous solution of w [SDS (sodium lauryl sulfate)] = 2% as an emulsifier, m : 1, emulsifying speed of 800 r / min conditions can be structured, wall thickness of 1 ~ 2μm, and the particle size concentrated in (10 ± 2) μm magnetic microcapsules. The capsule has a saturation magnetization of 36.9 emu / g and has good magnetic responsiveness.