Collapse Transition of Two-Dimensional Flexible and Semiflexible Polymers

TL;DR

This paper investigates the collapse transition of two-dimensional polymers, revealing it is first-order for flexible polymers and second-order for semiflexible ones, supported by analytical and simulation results.

Contribution

It provides a detailed analysis of the order of the collapse transition in 2D polymers based on bending stiffness, combining analytical models with Monte Carlo simulations.

Findings

Collapse transition is first-order for semiflexible polymers.

Transition becomes second-order at zero bending stiffness.

Results are supported by Monte Carlo simulations.

Abstract

The nature of the globule-coil transition of surface-confined polymers has been an issue of debate. Here this 2D collapse transition is studied through a partially directed lattice model. In the general case of polymers with positive bending stiffness ($\Delta>0$), the collapse transition is {\em first-order}; it becomes {\em second-order} only in the limiting case of zero bending stiffness ($\Delta\equiv 0$). These analytical results are confirmed by Monte Carlo simulations. We also suggest some possible future experiments.