Bidisperse magneto-rheological fluids consisting of functional SPIONs added to commercial MRF
Bidisperse magneto-rheological fluids consisting of functional SPIONs added to commercial MRF
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DOI：
10.1016/j.jiec.2020.07.040
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发表时间：
2020-08
影响因子：
6.1
通讯作者：
M. Nejatpour;U. Unal;H. Acar
中科院分区：
文献类型：
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作者：
M. Nejatpour;U. Unal;H. Acar
磁流变流体（mrf）是一种智能材料，当施加外部磁场（磁流变效应）时，具有从液体到半固体状态的可逆和快速转变。微米级磁性颗粒在商用磁流变仪中的沉降是限制其长期工业应用的关键问题。在这里，我们开发了一种基于商用140-CG LORD®的新型磁流变液，并添加了表面功能超顺磁性氧化铁粒子（SPIONs）。这些新的双分散磁磁共振f由聚丙烯酸（PAA）包覆的SPIONs或月桂酸（LA）包覆的SPIONs和微米尺寸的脂肪酸包覆的商业磁磁共振f磁性颗粒组成。SPIONs具有与微米级铁粒子的脂肪酸涂层相互作用的特殊涂层。研究了6 - 12wt % SPION双分散磁流变材料的沉降行为和磁流变特性。双分散磁流变液提高了磁流变液的稳定性和再分散性。含有12% SPION-PAA的双分散MRF，尽管其微米级铁颗粒含量较低，但其磁流变性能与商用MRF相似或更好。因此，可磁化的纳米级和微米级粒子的组合，以及正确的表面化学的利用，使它们能够良好地相互作用，从而提高磁流变函数的稳定性，而不会牺牲磁响应，甚至可以改善磁响应。
Magnetorheological fluids (MRFs) are smart materials with a reversible and fast transition from a liquid to a semi-solid state when an external magnetic field is applied (magnetorheological effect). The sedimentation of micron-sized magnetic particles in commercial MRFs is a crucial problem limiting the long-term use in industrial applications. Here, we develop a new MRF based on commercial 140-CG LORD® with the addition of surface functional superparamagnetic iron oxidenanoparticles (SPIONs). These new bidisperse MRFs are comprised of either poly(acrylic acid) (PAA) coated SPIONs or lauric acid (LA) coated SPIONs and micron-sized fatty acid-coated magnetic particles of the commercial MRF. SPIONs have specific coatings to interact with the fatty acid coating of the micron-sized Fe-particles. Sedimentation behaviour and the magnetorheological properties of these bidisperse MRFs with 6–12 wt% SPION were examined. Bidisperse MRFs improved the stability and redispersibility of MRFs. Bidisperse MRFs with 12 wt% SPION-PAA showed similar or better magnetorheological behaviour than the commercial MRF despite lower content of the micron size Fe-particles. Hence, a combination of magnetizable nano and micron-sized particles and utilization of correct surface chemistry that allows their favourable interaction improves the stability of MRFs without sacrificing magnetic response but even by improving it.