Polymer Dynamics and Molecular Simulations

Polymer dynamics seeks to unravel how chain architecture, intermolecular interactions and external forces govern the motion and relaxation of macromolecules across time and length scales. Molecular simulations—ranging from atomistic to coarse-grained approaches—have become indispensable for predicting viscoelastic response, self-assembly and topological evolution in systems as diverse as synthetic plastics, biological filaments and nanocomposites. By coupling detailed trajectories with theoretical models, researchers can link microscopic entanglement networks and confinement effects to macroscopic properties such as stiffness, diffusivity and flow behaviour. Recent advances incorporate activity, non-equilibrium driving and complex topologies to explore phenomena from glassy arrest in ring polymers to controlled knotting under confinement, with implications for materials design, biomedical engineering and fundamental statistical physics.

Research from Nature Portfolio

One investigation demonstrated that adding active segments to dense solutions of circular polymers can induce a novel glassy state. Here, self-driven mobility enhances mutual threading of loops, forcing relaxation to occur only via highly cooperative rearrangements and dramatically slowing stress relaxation. Another approach integrates nanochannel confinement experiments with theoretical modelling to generate and detect knots in single DNA chains. By compressing individual molecules against barriers and analysing extension profiles, the study derives a scaling-based free-energy description of knot formation, captures departures from simple Poisson statistics at high compression and highlights the role of self-exclusion in stabilising complex topological states.

Research from all publishers

Work on enzymatically driven polymer composites has revealed dynamic state-switching between elastic and dissipative regimes in circular DNA–dextran networks. Time-resolved rheometry shows abrupt transitions that are decorrelated from digestion kinetics; sigmoidal two-state modelling attributes these switches to cooperative percolation of entanglement clusters. In simulations of semiflexible polyelectrolyte rings, varying counterion valence controls assembly pathways: low levels of trivalent ions stabilise cylindrical stacks via ion bridging, while monovalent ions lead to reentrant clustering and osmotic collapse at high concentration, producing characteristic cluster-glass dynamics. High-resolution microscopy combined with steered molecular dynamics has further mapped the topology of two-dimensional DNA networks, uncovering heterogeneous minicircle linking and a buckling transition akin to an elastic thermal sheet; mechanical measurements estimate network moduli far below those of other two-dimensional materials, informing the design of synthetic topological assemblies.

Polymer Dynamics and Molecular Simulations publication trend

The graph below shows the total number of articles in polymer dynamics and molecular simulations across all publications each year (not limited to Nature Index journals).

Technical terms

Polymer dynamics: The study of how polymer chains move, relax and respond to forces in various environments.

Molecular dynamics simulation: A computational method that tracks the time evolution of interacting particles by integrating classical equations of motion.

Ring polymer: A polymer chain whose ends are joined to form a closed loop, introducing permanent topological constraints.

Entanglement: A topological interaction in which polymer chains interlace, restricting their motion and affecting rheological properties.

Glassy state: A non--equilibrium phase in which molecular mobility is arrested over experimental timescales, exhibiting solid-like behaviour.

Rheology: The field that examines the flow and deformation of materials under applied stress or strain.

Knotting probability: The likelihood that a flexible chain under given conditions adopts a knotted conformation.

References

1. Active topological glass. Nature Communications (2020).
2. A nanofluidic knot factory based on compression of single DNA in nanochannels. Nature Communications (2018).
3. Cooperative Rheological State‐Switching of Enzymatically‐Driven Composites of Circular DNA And Dextran. Advanced Materials (2023).
4. Cluster Formation in Solutions of Polyelectrolyte Rings. ACS Nano (2023).
5. Single-Molecule Structure and Topology of Kinetoplast DNA Networks. Physical Review X (2023).