Dependence of the polymer adsorption transition on chain stiffness and surface interaction range: A...

Area of Science:

• Materials Science
• Biophysics
• Computational Chemistry

Background:

• Understanding polymer chain adsorption to surfaces is crucial in materials science and biophysics.
• Adsorption transition temperature (Tc) depends on polymer flexibility (lp) and surface potential range (λ).
• Simulating long polymer chains to verify scaling laws is computationally intensive.

Purpose of the Study:

• To develop a finite-size scaling method using partition function zeros to determine adsorption transition temperatures in the long-chain limit.
• To investigate the influence of polymer flexibility and surface potential range on adsorption behavior.
• To identify and characterize distinct scaling regimes for polymer adsorption.

Main Methods:

• Employed a finite-size scaling method utilizing partition function zeros to extrapolate adsorption transition temperatures.
• Utilized Wang-Landau simulations to obtain the density of states for model polymer chains (tangent-hard-sphere) with varying persistence lengths (lp) and surface potential ranges (λ).
• Analyzed chains up to length N=2560 across a wide parameter space (1≤lp/σ≤13,100 and 0.01≤λ≤20).

Main Results:

• Successfully obtained adsorption transition temperatures in the long-chain limit from simulations of moderate-length chains.
• Identified three distinct scaling regimes: worm-like-chain, expanded-coil, and single-bead-interaction, consistent with theoretical predictions.
• Demonstrated that in the rigid-rod limit, the transition temperature approaches infinity for infinitely long chains.

Conclusions:

• The proposed finite-size scaling method is effective for studying polymer adsorption transitions, overcoming limitations of direct long-chain simulations.
• The study confirms and refines scaling laws for polymer adsorption across different flexibility and surface interaction regimes.
• Provides valuable insights into the fundamental behavior of semiflexible polymers interacting with attractive surfaces.