Choi Junsok, Nam Ki Tae, Kim Sehyun, Seo Yongsok
RIAM, Department of Materials Science and Engineering, College of Engineering, Seoul National University, Kwanakro-1, Kwanak-gu, Seoul 08826, Korea.
Polymer Processing Technology Team, LG Chemical Ltd./Tech Center, Moonjidong 104-1, Yusungku, Daejon 34114, Korea.
Nano Lett. 2021 Jun 23;21(12):4973-4980. doi: 10.1021/acs.nanolett.1c00674. Epub 2021 Jun 2.
We investigated the magnetorheological (MR) properties of the carbon nanotube (CNT)-CoFeNi composite suspension to find a high-performance MR fluid with excellent stability. The composites were fabricated by chemical reduction of CoFeNi on the surface of amine-functionalized CNTs. A synergistic effect between the high aspect ratio of the CNTs and the strong magnetic polarization of the CoFeNi led to stronger MR performance of the nanocomposite particle suspension. The MR fluid exhibits an unexpected high yield stress value that is 13 times greater than that of a CNT-FeO suspension at a magnetic field strength of 343 kA/m. Nonmagnetic CNTs form a three-dimensional networklike structure, imparting surprisingly large additional yield stress to the CNT-CoFeNi nanocomposite MR suspension. The low density of the CNTs resulted in much better long-term stability for the CNT-CoFeNi nanocomposite suspension than the MR fluid containing only CoFeNi.
我们研究了碳纳米管（CNT）-CoFeNi复合悬浮液的磁流变（MR）特性，以寻找一种具有出色稳定性的高性能MR流体。通过在胺官能化碳纳米管表面化学还原CoFeNi制备了复合材料。碳纳米管的高长径比与CoFeNi的强磁极化之间的协同效应导致纳米复合颗粒悬浮液具有更强的MR性能。在343 kA/m的磁场强度下，该MR流体表现出意想不到的高屈服应力值，比CNT-FeO悬浮液的屈服应力值大13倍。非磁性碳纳米管形成三维网络状结构，为CNT-CoFeNi纳米复合MR悬浮液赋予了惊人的大附加屈服应力。碳纳米管的低密度使得CNT-CoFeNi纳米复合悬浮液比仅含CoFeNi的MR流体具有更好的长期稳定性。
