【作者】 贾新根；

【导师】 沈德久；

【作者基本信息】 燕山大学 ， 材料学， 2012， 硕士

【摘要】 磁流变体是由微米级磁性颗粒分散在载液中形成的稳定悬浮液，主要由基液（分散介质）、分散颗粒（分散质）、添加剂（稳定剂）等部分组成。本文从分散质和基液的制备工艺方面对磁流变体进行研究。一方面，在聚苯乙烯泡沫表面进行化学镀Ni-Fe，得到具有磁性的泡沫颗粒作为磁流变体的轻质分散颗粒。对化学镀后的泡沫颗粒进行表面和截面形貌检测，结果显示，化学镀层均匀致密，镀层厚度达微米，镀层沿着基体表面生长并渗入基体内部，镀层和基体结合良好；能谱分析表明镀层中铁元素含量在25%以上，具有较好的磁性。计算结果表明，磁性粒子的密度值为0.193g/cm³，镀层表观密度为1.994g/cm³。另一方面，本文采用磁性液体作为磁流变体的基液，而非水、硅油等传统型分散介质。通过化学共沉淀法制备纳米Fe₃O₄磁性液体，主要从以下四个方面进行工艺参数优化：（1）制备纳米Fe₃O₄磁性粒子过程中油酸和氨水加入顺序（2）Fe²⁺/Fe³⁺不同摩尔配比（3）反应温度（4）磁性液体中油酸的加入量。结果表明：当反应过程中先滴加氨水，在溶液中出现棕色混浊时开始滴加一定量的油酸，在氨水加完前，油酸滴加结束，最后将氨水滴完，Fe2+/Fe³⁺摩尔比为1:1.65，反应温度为65℃，0.01molFe₃O₄磁性粒子中加入0.7ml的油酸时，制得的纳米Fe₃O₄磁性粒子粒径最小，粒子分布状况最好，磁性液体稳定性最好，同时饱和磁化强度值最大。更多还原

【Abstract】 Magnetorheological Fluids is a class of suspension that is made up of um-grademagnetic partcles dispersed in carrier liquid. It mainly consists of base fluid （dispersionmedium）, dispersion particles （dispersion） and additive （stabilizer）, etc. The preparationand properties of base fluid and light magnetic dispersion are the two main investigationparts in this paper.As for the dispersion, Ni-Fe was electroless plated on polyurethane foam particles toget magnetorheological fluids with light magnetic dispersion. The surface andcross-section morphology of the particles after electroless plated were investigated, Theresults show that the plating is lack of flatness, and the distribution of elements on platingis uneven. The composition of Fe is over25%, which indicates a good magnetic property.Finally, according to the weight and radius of the magnetic particle along with thethickness of the plating，the density of magnetic particles and plating are calculated to be0.193g/c m3and1.994g/cm³, respectively.On the other side, the magnetic fluid will be used as the base fluid of themagnetorheological fluids. As a result, the preparation and properties of magnetic fluid ofFe₃O₄were researched. The four main aspects in this part are:1) the sequence of addingoleic acid and ammonia in the preparation of Fe₃O₄;2) the ratio of Fe²⁺0and Fe³⁺;3) thecontrol of reacting temperature in the preparation of Fe₃O₄magnetic particle;4) thequantity of the added oleic acid. The final results show that the optimal technique ofpreparation Fe₃O₄in nanometer is as follows: adding oleic acid and ammoniasimultaneously. In other words, drip ammonia firstly, and then drip oleic acid when thesolution shows brown opacity, but finish the dripping of oleic acid before that of ammonia.The ratio of Fe2+/Fe3+is1:1.65. the reacting temperature is65℃, and the adding amountof oleic acid is0.7ml.更多还原