  Single polymer dynamics offers a powerful approach to study molecular-level
interactions and dynamic microstructure in materials. Direct visualization of
single chain dynamics has uncovered new ideas regarding the rheology and
non-equilibrium dynamics of macromolecules, including the importance of
molecular individualism, dynamic heterogeneity, and molecular sub-populations
that govern macroscale behavior. In recent years, the field of single polymer
dynamics has been extended to increasingly complex materials, including
architecturally complex polymers such as combs, bottlebrushes, and ring
polymers and entangled solutions of long chain polymers in flow. Single
molecule visualization, complemented by modeling and simulation techniques such
as Brownian dynamics and Monte Carlo methods, allow for unparalleled access to
the molecular-scale dynamics of polymeric materials. In this review, recent
progress in the field of single polymer dynamics is examined by highlighting
major developments and new physics to emerge from these techniques. The
molecular properties of DNA as a model polymer are examined, including the role
of flexibility, excluded volume interactions, and hydrodynamic interactions in
governing behavior. Recent developments in studying polymer dynamics in
time-dependent flows, new chemistries and new molecular topologies, and the
role of intermolecular interactions in concentrated solutions are considered.
Moreover, cutting-edge methods in simulation techniques are further reviewed as
an ideal complementary method to single polymer experiments. Future work aimed
at extending the field of single polymer dynamics to new materials promises to
uncover original and unexpected information regarding the flow dynamics of
polymeric systems.
