Drying-freeing preparation and property tests on MR fluid with MWCNTs/GO-coated CI particles

The traditional preparation processes for magnetorheological (MR) fluids are complicated and time-consuming, and cannot guarantee the performance of the prepared material, especially for the MR fluid with mixed coated particles. In this study, an improved drying-free preparation method of MR fluids was proposed, which adopts the magnetic separation technology to replace the traditional drying process, and an integrated preparation device for preparing MR fluids was designed on this basis to realize high efficiency and automation. The MR fluid with multiwalled carbon nanotube/graphene oxide-coated carbonyl iron particles was prepared using the designed device, and the test results showed that the drying-free preparation process can save 1/3 of the original preparation time. Then, the zero-field viscosity, yield shear stress and sedimentation rate of the prepared MR fluid were tested and compared with those prepared by the manual preparation methods. Under appropriate proportion of ingredients, the MR fluid prepared by the drying-free process has higher yield shear stress and better sedimentation stability. Therefore, the drying-free preparation process and the integrated preparation device proposed in this study are not only efficient and automated, but also can improve the performance of MR fluids.