The dynamics of filaments in low-Reynolds-numbers are related to many classical problems in fluid mechanics which are of great interest in different contexts. To give an idea of the broad interest, we have the swimming dynamics of flagella organisms and the fiber orientation when processing composite materials. The coupling between imposed flows, elastic effects, body forces, and hydrodynamic interactions induces complex dynamics of deformation and orientation, impacting the micro and macro transport phenomena. In this talk, I will present recent findings on two topics of my research: the settling dynamics of semi-flexible polymers and the rheology of colloidal rods. In the first part of the talk, I’ll elaborate on the mechanisms of knot formation in semi-flexible polymers subjected to strong body forces, as in ultracentrifugation and electrophoresis techniques. In the second part, I’ll discuss the effects of rod hydrodynamic interactions in the rheology of colloids at high shear rates and how such interactions trigger a cascade-like tumbling effect.
