Translocation of an active polymer into a two dimensional circular nano-container

Area of Science:

• Polymer Physics
• Soft Matter Physics
• Nanotechnology

Background:

• Understanding polymer behavior at the nanoscale is crucial for developing advanced materials and devices.
• Active polymers, capable of self-propulsion, exhibit complex dynamics distinct from passive counterparts.
• Nano-containers offer confined environments that significantly alter polymer translocation processes.

Purpose of the Study:

• To investigate the translocation dynamics of an active semi-flexible polymer through a nanopore into a circular nanocavity.
• To determine the scaling relationship between translocation time and self-propelling force (force exponent).
• To analyze the polymer's configurational regularity within the nanocavity based on container size and force strength.

Main Methods:

• Langevin dynamics simulations were employed to model the polymer translocation process.
• The study analyzed the force exponent (β) characterizing the average translocation time (⟨τ⟩) as a function of self-propelling force (Fsp).
• The turning number was used to quantify the polymer's configurational regularity inside the nanocavity.

Main Results:

• The force exponent (β) was found to be -1 for small nanocontainer radii (R ≪ Rg).
• For large nanocontainer radii (R ≫ Rg), the asymptotic value of the force exponent approached -0.93.
• The polymer configuration was more regular at the end of translocation for small R and strong forces.

Conclusions:

• The translocation dynamics of active semi-flexible polymers are highly dependent on the nanocavity's size.
• The force exponent exhibits distinct regimes, indicating different translocation mechanisms under varying confinement.
• Polymer configuration regularity is influenced by both nanocavity size and the applied self-propelling force.