Effect of magnetic nanoparticles and their functionalization on liquid crystal order

We have added magnetic nanoparticles with a different surface termination (functionalization) to smectic A 8CB liquid crystals and studied their effects on the order of the liquid crystal. This is done by looking at the liquid crystals both with polarized optical microscopy and by X-ray scattering. Adding the magnetic nanoparticles improves the liquid crystal's response to a magnetic field by at least one to two orders of magnitude. We have performed the experiments with four types of organic compounds covering the nanoparticles and have found that with 11nm particles covered with polyethelene glycol (PEG) 3000 the liquid crystal exhibits the largest effect as a function of the applied magnetic field.