Magnetic pickering emulsions heated in a rotating magnetic field

Emulsion stabilized by solid particles that accumulate at the surface of droplets is called Pickering emulsion. Depending on the application, solid particles of different properties can be utilized as stabilizers. Magnetic nanoparticles are interesting choice as they can stabilize the emulsion and become heat sources in the presence of external magnetic field. To generate heat, researchers commonly use easily accessible alternating magnetic field, however, the use of rotating magnetic field yields possibility of higher heat output. Our study presents results of calorimetric measurements obtained for oil-in-oil emulsion stabilized by magnetic nanoparticles under the influence of a rotating magnetic field. In our system rotating magnetic field is produced by four separate magnetic fluxes shifted in phase and space by 90 degrees. Results show that the use of rotating magnetic fields efficiently heat Pickering emulsion stabilized by magnetite particles. It also provides improved heating effect comparing to alternating magnetic fields, regardless of shape of the stabilizing particles. The results for magnetic emulsions were also compared to those for magnetic suspensions.