Deformation Dynamics of Semiflexible Colloidal Chains

We present the dynamics of semiflexible Brownian filaments under various flow fields. The filaments under consideration are composed of linked colloidal particles that form bead spring-like chains. Non-local hydrodynamic interactions cause the filaments to bend and rotate to align their end-to-end direction perpendicular to the forcing direction. Different reorientation mechanisms are varied for different regimes of flexibility. The competition between the reorientation mechanisms and the Brownian effects results in normal distributions of the orientation of the chains. When the chains are stiff, these fluctuations cause the chains to flow faster than their reciprocal non-Brownian cases. With increasing flexibility, thermal fluctuations lead to more compact configurations of the chains and higher average settling velocity. Chain flexibility also plays an important role when considering lateral chain motion. The interplay between elastic, gravitational, and thermal forces leads to important secondary influences on the flow dynamics of semiflexible chains.