Liquids magnetorheological

Magnetorheological materials (fluids) are the magnetic equivalent of electrorheological fluids. In this case, the particles are either ferromagnetic or ferrimagnetic solids that are either dispersed or suspended within a liquid and the applied field is magnetic (14). 

So far, applications for electrorheological and magnetorheological liquids are rather limited in number, but researchers predict that they will eventually find a number of applications in industry, aerospace, the military, and other fields. As with other fields of materials science, much more basic research is needed to understand the behavior of electrorheological and magnetorheological liquids before everyday applications can be developed. 

There are also complex fluids that change from solid-like to liquid-like, or vice versa, when subjected to a modest deformation. Complex fluids of this type include particulate and polymeric gels. Some fluids change to solids when an electric or magnetic field is applied these are electrorheological and magnetorheological suspensions. A classical liquid or solid, on the other hand, does not change character in response to a weak field unless it is extremely close to a phase transition temperature. 

A typical magnetorheological fluid consists of 20... 40% by volume of relatively pure, elemental iron particles suspended in a carrier liquid such as mineral oil, synthetic oil, water and/or glycol. A variety of proprietary additives, similar to those found in commercial lubricants, that inhibit gravitational settling and promote particle suspension, enhance lubricity, modify viscosity, and inhibit wear are commonly added. 

Keywords elastomer composites magnetic properties magnetorheological properties magnetoactive fillers ionic liquids... 

Additionally, to improve the dispersion of the applied filler properties, ionic liquids were added during preparation. No matter what kind of IL was admixed, all composites demostrated magnetic properties regardless of the type of elastomer matrix, applied filler or ionic hquid. Moreover, an increase of magnetisation values was observed for magnetorheological NBR composites with micro-sized magnetite containing ionic liquids comp>ared to vulcanisates where no ionic liquid was applied. 

Guerrero-Sanchez C, Lara-Ceniceros T, Jimenez-Regalado E, Rasa M, Schubert US (2007) Magnetorheological fluids based on ionic liquids. Adv Mater 19(13) 1740. doi 10.1002/ adma.200700302... 

Magnetorheological fluids based on ionic liquids. Adv. Mater., 19,1740-1747 Hitchcock, P. B. Seddon, K. R. Welton, T. (1993). Hydrogen-bond acceptor abilities of tetrachlorometalate(ll) complexes in ionic liquids. /. Chem. Soc., Dalton Trans., 2639-2643... 

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