Salem Ayman M H, Ali Abdelrahman, Ramli Rahizar Bin, Muthalif Asan G A, Julai Sabariah
Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia.
Department of Mechanical and Industrial Engineering, College of Engineering, Qatar University, Doha P.O. Box 2713, Qatar.
Polymers (Basel). 2022 Oct 6;14(19):4193. doi: 10.3390/polym14194193.
Magnetorheological elastomers (MREs) are smart viscoelastic materials in which their physical properties can be altered when subjected to a varying magnetic field strength. MREs consist of an elastomeric matrix mixed with magnetic particles, typically carbonyl iron particles (CIPs). The magnetic field-responsive property of MREs have led to their wide exposure in research. The potential development and commercialization of MRE-based devices requires extensive investigation to identify the essential factors that can affect their properties. For this reason, this research aims to investigate the impact of CIPs' type, concentration and coating on the rheological and mechanical properties of MREs. Isotropic MREs are fabricated with four different CIP compositions differing between hard or soft, and coated or uncoated samples. Each MRE composition have three different concentrations, which is 5%, 10%, and 20% by volume. The dynamic properties of the fabricated samples are tested by compression oscillations on a dynamic mechanical analyzer (DMA). Frequency and strain dependent measurements are performed to obtain the storage and loss modulus under different excitation frequencies and strain amplitudes. The emphasis is on the magnetorheological (MR) effect and the Payne effect which are an intrinsic characteristics of MREs. The effect of the CIPs' type, coating, and concentration on the MR and Payne effect of MREs are elucidated. Overall, it is observed that, the storage and loss modulus exhibit a strong dependence on both the frequency excitations and the strain amplitudes. Samples with hard and coated CIPs tend to have a higher MR effect than other samples. A decrease in the storage modulus and non-monotonous behavior of the loss modulus with increasing strain amplitude are observed, indicating the Payne effect. The results of this study can aid in the characterization of MREs and the proper selection of CIPs grades based on the application.
磁流变弹性体（MREs）是一种智能粘弹性材料，当受到变化的磁场强度作用时，其物理性能会发生改变。MREs由弹性体基质与磁性颗粒（通常为羰基铁颗粒，CIPs）混合而成。MREs的磁场响应特性使其在研究中得到了广泛关注。基于MREs的器件的潜在开发和商业化需要进行广泛的研究，以确定可能影响其性能的关键因素。因此，本研究旨在探讨CIPs的类型、浓度和涂层对MREs流变学和力学性能的影响。采用四种不同的CIP组成制备各向同性MREs，这些组成在硬或软以及涂层或未涂层样品之间有所不同。每种MRE组成有三种不同的浓度，按体积计分别为5%、10%和20%。通过在动态力学分析仪（DMA）上进行压缩振荡来测试制备样品的动态性能。进行频率和应变相关的测量，以获得不同激励频率和应变幅值下的储能模量和损耗模量。重点关注磁流变（MR）效应和佩恩效应，它们是MREs的固有特性。阐明了CIPs的类型、涂层和浓度对MREs的MR效应和佩恩效应的影响。总体而言，观察到储能模量和损耗模量对频率激励和应变幅值都有很强的依赖性。含有硬涂层CIPs的样品往往比其他样品具有更高的MR效应。观察到随着应变幅值增加，储能模量降低且损耗模量呈现非单调行为，这表明了佩恩效应。本研究结果有助于对MREs进行表征，并根据应用情况正确选择CIPs等级。
