(270c) Flow and Segregation of a Mixture of Passive and Responsive, Magnetically-Driven Rotating Particles
AIChE Annual Meeting
Tuesday, November 15, 2022 - 8:36am to 8:54am
What has not previously been explored is the behavior of granular systems where shear is introduced to the system through torque applied directly to the particles themselves. In this work, a granular system of 50 micron ferromagnetic Janus particles is prepared. These responsive Janus particles are rotated through the application of magnetic torque by an external rotating magnetic field resulting in uphill granular heaping which for all purposes demonstrates quintessential granular behavior, such as boundary layer flow, but against gravity, giving rise to a negative angle of repose (downhill to uphill). When mixed with other non-functionalized particles, segregation occurs that may rise to well-known fluid instabilities. It is proposed that the behavior is governed frictional control as a direct result of the magnetic field strength. These observations elucidate a whole new way to observe granular systems and have a significant impact on the way in which granular systems could be applied.