Transport of a comb-like polymer across a nanochannel subject to a pulling force

• Published in: Journal of physics. Condensed matter Vol. 36; no. 50; pp. 505103 - 505115
• Main Authors: Adane, Meseret, Tatek, Yergou B, Tilahun, Mesay
• Format: Journal Article
• Language: English
• Published: England IOP Publishing 18.12.2024
• Subjects: coarse-grained; comb-like polymer; grafting density; Langevin dynamics; nanochannel; translocation; comb-like polymer; nanochannel; translocation; Langevin dynamics; coarse-grained; grafting density
• ISSN: 0953-8984; 1361-648X; 1361-648X
• DOI: 10.1088/1361-648X/ad7e70

We investigate the dynamics of comb-like polymer translocation through a nanochannel using three-dimensional Langevin dynamics simulations based on a coarse-grained chain model. A comprehensive set of simulations are performed to examine the effects of system parameters such as the grafting density ρ of the side chains, the polymer chain length, the nanochannel dimensions, and the magnitude of the pulling force on the translocation dynamics. For a given polymer chain length, keeping the backbone length is constant while varying ρ , we have found that the dependence of the mean translocation time ⟨ τ ⟩ on ρ is non-monotonic, with a maximum translocation time for a specific ρ at which the translocation is the slowest. The simulation results also show that ⟨ τ ⟩ is not significantly affected by the channel width above a certain radius, while the comb-like polymer translocation is hindered by a narrower channel due to increased interactions between the chain monomers and the channel. In addition, ⟨ τ ⟩ increases linearly with the nanochannel length. A linear scaling relationship between the mean translocation time ⟨ τ ⟩ and the chain length N of polymer is obtained, ⟨ τ ⟩ ∼ N . Similarly, the dependence of ⟨ τ ⟩ on the backbone chain size N bb has a quasi-linear dependence, ⟨ τ ⟩ ∼ N bb . On the other hand, the translocation velocity v follows a power-law relationship with the polymer chain length N as v ∼ N − 1 . The mean translocation time also shows an inverse linear relationship with the magnitude of the pulling force F , ⟨ τ ⟩ ∼ F − 1 . The power-law relationships discovered in this study contribute to the fundamental understanding of the comb polymer translocation dynamics and to establishing a framework for further investigations in this field.