Colloidal dispersibility of fatty acid-capped iron nanoparticles and its effect on static and dynamic magnetorheological response
Colloidal dispersibility of fatty acid-capped iron nanoparticles and its effect on static and dynamic magnetorheological response
复制标题
脂肪酸封端铁纳米颗粒的胶体分散性及其对静态和动态磁流变响应的影响
DOI：
10.1016/j.colsurfa.2012.10.012
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Yoshikazu Kuga et. al.
中科院分区：
文献类型：
--
作者：
Shinya Yamanaka; Yoshikazu Kuga et. al.
在这里，我们报告了含有脂肪酸封端的铁纳米粒子的浓悬浮液的胶体结晶及其对静态和动态磁流变（MR）响应的影响。表面吸附的脂肪酸的量控制了纳米粒子的非场分散状态以及弱絮凝和强絮凝结构。在磁场强度为B=0.5T时，两种材料的屈服应力均约为0.5T。14-16 kPa由于絮凝结构对场依赖性屈服应力的影响可以忽略不计，因此非场分散状态主要决定翻起比; B= 0.5 T时的屈服应力与B=0时的剪应力（1 s-1时）之比。动态测量结果表明，在场致聚集结构中，两种分散态是不同的。弱絮凝悬浮液出现粘弹性线性区域，而强絮凝悬浮液则没有粘弹性线性区域。此外，胶体稳定性的两个分散状态进行了讨论的对势能。
Herein we report colloidal dispersibility of concentrated suspensions containing fatty acid-capped iron nanoparticles and its influence on the static and dynamic magnetorheological (MR) response. The amount of fatty acid absorbed on the surface controls the non-field dispersion state as well as weakly and strongly flocculated structure of the nanoparticles. Both yield stress at B=0.5T of an applied magnetic field is ca. 14–16kPa Because the flocculated structure has a negligible effect on the field-dependence yield stress, the non-field dispersion state mainly determines the turn-up ratio; the ratio of the yield stress at B=0.5T to shear stress (at 1s−1) at B=0. The dynamic measurements indicate that the two dispersion states are different in the field-induced aggregation structures. A viscoelastic linear region appears for a weakly flocculated suspension, and does not for a strongly flocculated suspension. Additionally, the colloidal stability for the two dispersion states is discussed in terms of pair potential energy.