Exploring conformations of comb-like polymers with varying grafting density in dilute solutions

Carlos A Salinas-Soto; Yeojin Choe; Su-Mi Hur; Abelardo Ramírez-Hernández

doi:10.1063/5.0160824

Exploring conformations of comb-like polymers with varying grafting density in dilute solutions

J Chem Phys. 2023 Sep 21;159(11):114901. doi: 10.1063/5.0160824.

Authors

Carlos A Salinas-Soto^{1

2}, Yeojin Choe³, Su-Mi Hur³, Abelardo Ramírez-Hernández^{1

2}

Affiliations

¹ Department of Biomedical Engineering and Chemical Engineering, The University of Texas at San Antonio, San Antonio, Texas 78249, USA.
² Department of Physics and Astronomy, The University of Texas at San Antonio, San Antonio, Texas 78249, USA.
³ Department of Polymer Engineering, Chonnam National University, Gwangju 61186, Republic of Korea.

PMID: 37712792
DOI: 10.1063/5.0160824

Abstract

Comb-like polymers have shown potential as advanced materials for a diverse palette of applications due to the tunability of their polymer architecture. To date, however, it still remains a challenge to understand how the conformational properties of these polymers arise from the interplay of their architectural parameters. In this work, extensive simulations were performed using dissipative particle dynamics to investigate the effect of grafting density, backbone length, and sidechain length on the conformations of comb-like polymers immersed in a good solvent. To quantify the effect of these architectural parameters on polymer conformations, we computed the asphericity, radius of gyration, and backbone and sidechain end-to-end distances. Bond-bond correlation functions and effective Kuhn lengths were computed to quantify the topological stiffness induced by sidechain-sidechain interactions. Simulation results reveal that the effective Kuhn length increases as grafting density and sidechain length increase, in agreement with previous experimental and theoretical studies. This increase in stiffness results in comb-like polymers adopting extended conformations as grafting density and sidechain length increase. Simulation results regarding the radius of gyration of comb-like polymers as a function of grafting density are compared with scaling theory predictions based on a free energy proposed by Morozova and Lodge [ACS Macro Lett. 6, 1274-1279 (2017)] and scaling arguments by Tang et al. [Macromolecules 55, 8668-8675 (2022)].