Optimizing Solid Lubricity in Complex Particle Flow

Granular matter flow is a complex many-body problem, especially for complex particles. Particle flow has been enhanced using solid lubricants, more recently redefined as network disruptors (NDs), given their role in in situ disrupting of force chains. Herein, we evaluate attributes of a recently reported ND to establish a criterion that can be adopted to enhance the fluency. We evaluate the effect of fiber shape, curl, lumen(s), mechanical strength, and surface heterogeneity on rheological flow energy. Cylindrical fibers showed enhanced fluency relative to flat fibers, while carbonization (pyrolysis) significantly enhanced fluency. Surprisingly, high tensile strength and high curl index correlate with significant reduction in flow energy and hence enhanced fluency. Correlation between high tensile strength and fluency affirms that these materials are force chain disruptors. Enhanced fluency with an increase in curl index suggests persistence of the additives in the granular matter matrix and hence continued force chain disruptions.