【作者】 董健媛；

【导师】 杨帆；

【作者基本信息】 华东师范大学 ， 无机化学， 2008， 硕士

【摘要】 本论文应用化学共沉淀法制备出了纳米级Fe₃O₄，考虑到磁流体载液的绿色化发展趋势，首次使用苹果酸和葡萄糖酸钠对纳米Fe₃O₄进行表面改性，进而分散于水中制得水基磁流体，讨论了制备过程中的影响因素，并对这两种水基磁流体的磁热和磁光性质做了初步研究。此外，使用离子液体作为新型载液，甜菜碱为表面活性剂制备了离子液体基磁流体，并讨论了相关影响因素。具体如下：1．用化学共沉淀法制备纳米级Fe₃O₄的工艺讨论应用常用的化学共沉淀法，以简单的实验装置和温和的反应条件制备出了粒径在6-9nm的Fe₃O₄粒子，饱和磁化强度为47emu／g，并对制备工艺中几个重要的因素进行了讨论，确定了最优反应条件：Fe²⁺∶Fe³⁺∶OH^-=2∶3∶15，铁盐浓度为0．15mol／L，反应温度为40℃。2．水基磁流体的制备及其性质研究首次尝试用苹果酸和葡萄糖酸钠作为表面活性剂对纳米Fe₃O₄进行表面改性，这两种表面活性剂价廉易得，可参与人体代谢，从而可被广泛应用于制备生物相容性水基磁流体。对会影响磁流体稳定性的几个因素进行了讨论，分别确定了两种水基磁流体的最佳制备条件：n苹果酸：nFe₃O₄=1：1，搅拌时间为60min，搅拌温度为35℃，在常温下能放置50天左右；n葡萄糖酸钠：nFe₃O₄=0．6：1，搅拌时间为60min，搅拌温度为35℃，在常温下能放置45天左右。这两种水基磁流体在磁场中都有明显的磁热效应，在63kHz，7kA／m的交变磁场中作用10min，升温速率最高可达到1．5℃／min。磁光效应同样明显，从肉眼上表现为边界效应。3．离子液体基磁流体的制备首次以化学稳定性好，蒸气压低的离子液体作为新型载液，用甜菜碱对纳米Fe₃O₄进行表面改性，制得了较稳定的离子液体基磁流体。对纳米复合粒子的组成、粒径、分布及磁性能进行了表征，对会影响磁流体稳定性的几个因素进行了讨论，确定了最佳制备条件：反应温度35℃，搅拌时间60min，以[C₆MeIm]BF₄为基液，甜菜碱用量为1ml，超声分散时间为7min，制得的磁流体可在室温下放置7天左右。更多还原

【Abstract】 This paper described the preparation of nanometer magnetite by applying thechemical co-precipitation.Considering the green development of ferrofluid’s basecarriers,we prepared the water-based ferrofluid using malic acid and sodiumgluconate as novel surfactants and investigated some influence factors.The heat effectand light effect in magnetic field were also studied.At last,we originally prepared theionic liquid-based ferrofluid using lycine as surfactant and investigated someinfluence factors.The specifical content are:1.The preparation of nanometer magnetite by applying the chemicalco-precipitationWe prepared the nano magnetite by applying the chemical co-precipitation.Thismethod just need ordinary equipment and facile experiment condition.The diameterof nanoparticles varies from 6nm to 9nm.These nanoparticles’ saturationmagnetization is 47emu/g.We investigated some influence factors in preparation tofind the best conditions:Fe²⁺:Fe³⁺:OH^-=2:3:15;molysite solution concentrationis 0.15mol/L;temperature is 40℃.2.The preparation of water-based ferrofluid and studies of its propertiesWe applied malic acid and sodium gluconate as novel surfactants to modify thesurface property of nano magnetite.These surfactants can participate in metabolismand have low price.They can be used to prepare bio-compatible water-basedferrofluids in large scale.We investigated some influence factors on the stability offerrofluid to find out the best preparation condition:n[malic acid]:n[Fe₃O₄]=1:1,stirring time is 60min,stirring temperature is 35℃,can keep stable within 50 days;n[sodium gluconate]:n[Fe₃O₄]=0.6:1,stirring time is 60min,stirring temperature is35℃,can keep stable within 45 days.The heat effect of these ferrofluids in magneticfield were studied.Under a alternating magnetic field （63kHz,7kA/m）,the maximumheating rate can reach 1.5℃/min.The light effect of these ferrofluids are obvious andmacroscopic too.3.The preparation of ionic liquid-based ferrofluid Considering the chemical stability and low vapor tension of ionic liquid,weoriginally prepared the ionic liquid-based ferrofluid using lycine as surfactant.Thecomposition,diameter,distribution and magnetism of particles are characterized.Weinvestigated some influence factors in preparation to find the best condition:stirringtemperature is 35℃,stirring time is 60min,using [C₆MeIm]BF₄ as base carrier,1mllycine,the time of using ultrasonic is 7min,this ferrofluid can keep stable within 7days.更多还原