Nanocomposites of Ferroelectric Liquid Crystals and Magnetic Nanoparticles: Potential Application as a MRI Contrast Agent

Nanocomposites of ferroelectric liquid crystals in combination with FeCo magnetic nanoparticles are considered as a MRI contrast agent, by creating a magnetic field as a function of the body’s electric field. The rotational viscosity of the sample needs to be reduced in order to reduce the electric field strength required for liquid crystal rotation to the values observed in many live biological states. This is achieved by having the nanoparticles act as lubricants to the ferroelectric liquid crystal. The magnetic field depends on the concentration of nanoparticles, which cannot be toxic to the biological environment. The concentrations used form aggregates that tend to exist in stable spherulites, that are also reversible with temperature. We find a relation between the magnetic field and the number of spherulites per unit area that align as a function of the electric field in the presence of a very small sample such as our model system. Finally, we present a model of how the electric field rearranges the spherulites and produces the magnetic field.