Effects of Polymer Topology and Crowder Size on Polymer Adsorption at Solid Interfaces
Akshay Chauhan, Srabanti Chaudhury
ChemPhysChem 27, e202500790 (2026) · doi:10.1002/cphc.202500790
Summary:
Polymers can have different shapes—some are open chains, while others form closed loops. In this work, we show that these topological differences strongly influence how polymers interact with surfaces when many surrounding particles are present. Our simulations reveal that looped (ring) polymers are much more prone to flatten and stick to surfaces under crowding, whereas linear polymers behave very differently. These findings have implications for DNA organization near cellular membranes and surfaces.
Influence of Crowder Geometry and Flexibility on Polymer Translocation Dynamics
Akshay Chauhan, Srabanti Chaudhury
Chemistry – An Asian Journal 20, e00621 (2025) · doi:10.1002/asia.202500621
Summary:
Inside cells, long molecules like DNA often have to pass through tiny pores while surrounded by many other macromolecules. In this work, we use computer simulations to show that not only the amount of crowding, but also the shape and flexibility of surrounding obstacles strongly affects how easily a polymer can move through a pore. Our results help explain why transport inside biological environments can vary widely depending on local structure and crowding conditions.
Understanding the Anti-Polyelectrolyte Effect in Polyzwitterions Using Coarse-Grained Molecular Dynamics
Akshay Chauhan, Srabanti Chaudhury
Journal of Physical Chemistry B 129, 3253–3262 (2025) · doi:10.1021/acs.jpcb.4c07728
Summary:
Most charged polymers shrink when salt is added to a solution. Surprisingly, some polymers instead expand—a phenomenon known as the anti-polyelectrolyte effect. In this study, we use simplified molecular simulations to understand why this counterintuitive behavior occurs in polyzwitterions. We show how ion–polymer interactions and charge screening work together to drive polymer expansion, providing insight relevant to soft materials and biomedical applications.
Multivalent Salt-Induced Self-Assembly of Amphiphilic Polyelectrolytes of Different Charge Fractions
Akshay Chauhan, Srabanti Chaudhury
Journal of Physical Chemistry B 128, 2037–2044 (2024) · doi:10.1021/acs.jpcb.3c07886
Summary:
Amphiphilic polymers—molecules with both water-loving and water-repelling parts—can spontaneously organize into structures like micelles. Using computer simulations, we demonstrate how adding multivalent salt ions can dramatically change this self-assembly process. We find that polymers can first cluster together and then redisperse as salt concentration increases, revealing a non-monotonic and highly tunable behavior important for drug delivery and soft-matter design.
Coupling Effects of Electrostatic Interactions and Salt Concentration Gradient in Polymer Translocation through a Nanopore: A Coarse-Grained Molecular Dynamics Simulations Study
Akash Dhabade, Akshay Chauhan, Srabanti Chaudhury
ChemPhysChem 24, e202200666 (2022) · doi:10.1002/cphc.202200666
Summary:
Charged polymers such as DNA often pass through tiny pores in membranes, driven by electric fields and influenced by the surrounding salt environment. Using computer simulations, we study how differences in salt concentration and solution acidity affect how strongly a polymer interacts with a nanopore and how fast it moves through it. We find that salt can both help and hinder translocation by reducing electrostatic repulsion while also generating additional driving forces that may compete with an applied voltage. These results show that polymer transport through nanopores is governed by a delicate balance between electric forces, salt effects, and polymer–pore interactions.
Manuscripts Under Review
Ring Polymer Dynamics in Crowded Confinement with Fluctuating Wall
Akshay Chauhan, Srabanti Chaudhury
Manuscript submitted