Tunable viscosity modification through particles: When particles decrease the viscosity of complex fluids

While spherical particles are the most studied viscosity modifiers, they are well known to increase the viscosity only. Extended studies and theories on non-spherical particles find a more complicated behavior, but still a steady increase. Involving platelets in combination with complex fluids displays an even more complex scenario that we analyze experimentally and theoretically as a function of platelet diameter, to find the concepts behind. Using this toolbox we were able to decrease the viscosity of crude oils although solid particles were added. This apparent contradiction might find a wider range of applications.