Investigating the kinetics of single-chain expansion upon release in theta conditions.

ABSTRACT: The free expansion of a confined chain in theta solvents following a sudden removal of the confining constraint is investigated using Langevin dynamics simulations in both two- and three-dimensional spaces. The average evolution of the chain size exhibits a sigmoidal transition between the confined and the free states on a logarithmic timescale, indicating a two-stage expansion, each characterized by its own timescale. A kinetic theory is developed by applying Onsager's variational principle, which balances the change in free energy with energy dissipation. Through scaling analysis, the characteristic time τ1 for the first expansion stage is shown to scale as the cube of the initial chain size, while the chain size increases according to a power law with an exponent α1=1/3 , independent of

SUBMITTER: Hsiao PY 

PROVIDER: S-EPMC11883026 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature