Simulation on the translocation of polymer through compound channels

Area of Science:

• Polymer Physics
• Computational Biophysics
• Soft Matter Science

Background:

• Polymer translocation through nanopores is crucial for biological processes and nanotechnology.
• Understanding polymer dynamics in confined geometries is essential for designing advanced materials.
• External fields significantly influence polymer behavior in channels.

Purpose of the Study:

• To investigate polymer translocation through a two-part compound channel under an external electrical field.
• To determine how varying channel interactions and lengths affect translocation efficiency.
• To identify optimal conditions for achieving the fastest polymer translocation.

Main Methods:

• Monte Carlo simulations were employed on a three-dimensional simple cubic lattice.
• A compound channel model with two distinct interaction regions (α and β) was used.
• The effects of varying interaction strengths (ε(α), ε(β)) and segment lengths (L(pα), L(pβ)) were systematically studied.

Main Results:

• Polymer translocation is significantly influenced by the interaction strength in part β (ε(β)) and the length of part α (L(pα)).
• Fastest translocation occurs at specific, optimized values of ε(β) and L(pα).
• When ε(β) is large, the final escape process dominates; when L(pα) is small and ε(β) ≪ ε(α), the initial filling process is critical, influenced by a free-energy well at the interface.

Conclusions:

• The study provides insights into optimizing polymer translocation through engineered channels.
• A balance between initial polymer chain entry and final exit is key for efficient translocation.
• The findings have implications for nanofluidic devices and polymer manipulation technologies.