Behavior of carbon cone particle dispersions in electric and magnetic fields

The behavior of carbon cone (CC) particle dispersions in electric and magnetic fields is presented. The behavior of CC dispersions in an ac electric field was studied by the use of electrorheological (ER) measurements. Low ac electric fields were sufficient for fibrilar structures to form. However the structures formed were relatively weak as determined by ER measurements and this was attributed to the high conductivity of the particles. This is also consistent with the low relaxation frequency found by impedance spectroscopy. The behavior of a dispersion of CC added ferrofluid was studied using magnetorheological measurements. The relative increase in viscosity was found to be around 1.2–1.5 for low magnetic fields and low shear rates. This was attributed to purely hydrodynamic effects caused by CC particle–particle interactions.