Tuning Knot Size of Knotted Circular Semiflexible Polyelectrolyte <italic style="font-style: italic">via</italic> Salt Concentration

Dan Lu; Ai-Hua Chai; Xiu-Xia Hu; Pei-Hua Zhong; Jian Wu; Nian-Qian Kang; Xian-Fei Kuang; Zhi-Yong Yang

doi:10.1007/s10118-025-3439-y

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Tuning Knot Size of Knotted Circular Semiflexible Polyelectrolyte via Salt Concentration

RESEARCH ARTICLE | Updated：2025-12-03

- Tuning Knot Size of Knotted Circular Semiflexible Polyelectrolyte via Salt Concentration
- Chinese Journal of Polymer Science Vol. 43, Issue 12, Pages: 2443-2454(2025)
- Affiliations：
  
  a.Department of Physics, Jiangxi Agricultural University, Nanchang 330045, China
  b.College of Mechanical Engineering (College of Robotics Engineering), Jiaxing University, Jiaxing 314001, China
  c.College of computer information and engineering, Jiangxi Agricultural University, Nanchang 330045, China
- Author bio：
  
  zhiyongyang2009@163.com
- Funds：
- DOI：10.1007/s10118-025-3439-y
  CLC： [M
- Received：13 July 2025，
  
  Revised：2025-08-12，
  
  Accepted：17 August 2025，
  
  Published Online：12 November 2025，
  
  Published：15 December 2025
- Accepted：
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Lu, D.; Chai, A. H.; Hu, X. X.; Zhong, P. H.; Wu, J.; Kang, N. Q.; Kuang, X. F.; Yang, Z. Y. Tuning knot size of knotted circular semiflexible polyelectrolyte via salt concentration. Chinese J. Polym. Sci. 2025, 43, 2443–2454

Dan Lu, Ai-Hua Chai, Xiu-Xia Hu, et al. Tuning Knot Size of Knotted Circular Semiflexible Polyelectrolyte via Salt Concentration[J]. Chinese Journal of Polymer Science, 2025, 43(12): 2443-2454.
Lu, D.; Chai, A. H.; Hu, X. X.; Zhong, P. H.; Wu, J.; Kang, N. Q.; Kuang, X. F.; Yang, Z. Y. Tuning knot size of knotted circular semiflexible polyelectrolyte via salt concentration. Chinese J. Polym. Sci. 2025, 43, 2443–2454 DOI： 10.1007/s10118-025-3439-y.

Dan Lu, Ai-Hua Chai, Xiu-Xia Hu, et al. Tuning Knot Size of Knotted Circular Semiflexible Polyelectrolyte via Salt Concentration[J]. Chinese Journal of Polymer Science, 2025, 43(12): 2443-2454. DOI： 10.1007/s10118-025-3439-y.

摘要

The knot size of a circular semiflexible polyelectrolyte (PE) in t

he presence of trivalent salt s studied using the molecular dynamics simulation package LAMMPS. The knot size can be tuned by the bending rigidity

of PE and the molar concentration of the salt

. The knot size decreases firstly

then increases with

increase.

Abstract

Knots are discovered in a wide range of systems

from DNA and proteins to catheters and umbilical cords

and have thus attracted much attention from physicists and biophysicists. Langevin dynamics simulations were performed to study the knotting properties of coarse-grained knotted circular semiflexible polyelectrolyte (PE) in solutions of different concentrations of trivalent salt. We find that the length and position of the knotted region can be controlled by tuning the bending rigidity

of the PE and the salt concentration

. We find that the knot length varies nonmonotonically with

in the presence of salt

and the knot localizes and is the tightest at

=5. As

the knot swells with

increase. In addition

similar modulations of the knot size and position can be achieved by varying the salt concentration

. The knot length varies nonmonotonically with

for

0. The knot localizes and becomes tightest at

=1.5×10

−4

mol/L in the range of

≤1.5×10

−4

mol/L. As

1.5×10

−4

mol/L

the knot of the circular semiflexible PE swells at the expense of the overall size of the PE. Our results lay the foundation for achieving broader and more precise external adjustability of knotted PE size and knot length.

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Keywords

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⁰

Tuning Knot Size of Knotted Circular Semiflexible Polyelectrolyte via Salt Concentration

DOI：10.1007/s10118-025-3439-y

摘要

Abstract

关键词

Keywords

references