Cross-linking driven collapse dynamics of polyelectrolyte single-chain in good solvents

Area of Science:

• Polymer Chemistry
• Computational Nanoscience
• Statistical Mechanics

Background:

• Intramolecular cross-linking is key for synthesizing single-chain nanoparticles (SCNPs).
• The dynamics of polyelectrolyte collapse driven by cross-linking are not fully understood.
• Understanding these dynamics is crucial for controlling SCNP microstructure.

Purpose of the Study:

• To investigate the mechanism of cross-linking-driven collapse dynamics in polyelectrolyte single-chains.
• To explore the influence of chain length and electrostatic strength on collapse dynamics.
• To develop a theoretical framework explaining the observed dynamics.

Main Methods:

• Coarse-grained dissipative particle dynamics (DPD) simulations were employed.
• Simulations analyzed the collapse dynamics of polyelectrolyte single-chains.
• A Model A-type dynamics theory was developed to explain simulation results.

Main Results:

• The collapse timescale exhibits a power-law dependence on chain length with a negative scaling exponent.
• This chain length dependence differs significantly from solvent-induced collapse dynamics.
• A non-monotonic dependence of collapse timescale on electrostatic strength was observed, influenced by counterion condensation.

Conclusions:

• The study elucidates the distinct dynamics of electrostatics-mediated cross-linking-driven collapse.
• A theoretical model explains the observed dependencies on chain length and electrostatic strength.
• Findings provide insights for precise control over SCNP microstructure synthesis.