Study of unzipping transitions in an adsorbed polymer by a periodic force

TL;DR

This study uses Monte Carlo simulations to analyze how an adsorbed polymer unzips under periodic force, revealing hysteresis behavior and scaling laws similar to DNA unzipping, across different surface types.

Contribution

It provides new insights into the dynamic unzipping transitions of polymers under periodic forces, with detailed scaling analysis and comparison to DNA studies.

Findings

Hysteresis loops observed in force-distance isotherms.

Hysteresis loop area scales as 1/ω at high frequency.

Scaling exponents α=1 and β=1.25 at low frequency.

Abstract

Using Monte Carlo simulations, we study the dynamic transitions in the unzipping of an adsorbed homogeneous polymer on a surface (or wall). We consider three different types of surfaces. One end of the polymer is always kept anchored, and other end monomer is subjected to a periodic force with frequency $\omega$ and amplitude $g_0$. We observe that the force-distance isotherms show hysteresis loops in all the three cases. For all the three cases, it is found that the area of the hysteresis loop, $A_{loop}$, scales as $1/\omega$ in the higher frequency regime, and as $g_0^{\alpha} \omega^{\beta}$ with exponents $\alpha = 1$ and $\beta = 1.25$ in the lower frequency regime. The values of exponents $\alpha$ and $\beta$ are similar to the exponents obtained in the earlier Monte Carlo simulation studies of DNA chains and a Langevin dynamics simulation study of longer DNA chains.