Stability behaviour of composite magnetorheological fluids by an induction method Iglesias Salto, Guillermo Ramón Roldán Aranda, Andrés María Reyes, Luis Rodríguez Arco, Laura García López-Durán, Juan De Dios Magnetorheological Fluids Stability Sedimentation profile Multi-component magnetic suspension Magnetic particles Non-magnetic particles In this work we study the stability behaviour of composite magnetorheological (MR) fluids consisting of magnetic (iron) and non-magnetic (poly(methylmethacrylate), PMMA) particles dispersed in mineral oil. Because of the opacity of the suspensions, optical methods traditionally employed for evaluation of the gravitational settling in colloidal suspensions are not suitable for sedimentation follow-up in this case. For this reason, we use an alternative method based on the evaluation of the resonant frequency of the inductance of a thin coil surrounding the sample The movement of the coil along the height of the container at specified steps and time intervals allows obtaining information about the local volume fraction of particles inside the tube. The obtained successive profiles for the multi-component suspensions show a decrease of the iron particle settling and of the initial rate of settling as the PMMA volume fraction is increased. Finally, the increase of the PMMA concentration gives rise to an improvement of the rheological properties upon magnetic field application for a given concentration of iron. Both a strong rheological response and a good colloidal stability are essential for practical applications. 2015-09-25T10:19:39Z 2015-09-25T10:19:39Z 2015-09 info:eu-repo/semantics/preprint Iglesias, G.R.; et al. Stability behaviour of composite magnetorheological fluids by an induction method. Journal of Intelligent Material Systems and Structures: online (2015). [http://hdl.handle.net/10481/37664] 1045-389X http://hdl.handle.net/10481/37664 10.1177/1045389X15577656 eng http://creativecommons.org/licenses/by-nc-nd/3.0/ info:eu-repo/semantics/openAccess Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License SAGE Publications