A Variational Approach to Trap Macromolecules

Luofu Liu; Chao Duan; Rui Wang

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arXiv · 2404.13574

A Variational Approach to Trap Macromolecules

Luofu Liu·Chao Duan·Rui Wang

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Abstract

Trapping macromolecules is impoartant for the study of their conformations, interactions, dynamics and kinetic processes. Here, we develop a variational approach which self-consistently introduces a mean force that controls the center-of-mass position and a self-adjustable harmonic potential that counters the center-of-mass fluctuation. The effectiveness and versatility of our approach is verified in three classical yet not fully understood problems in polymer physics: (1) single-chain conformation in the entire solvent regimes, (2) globule-pearl necklace-coil transition of a polyelectrolyte and (3) inter-chain interaction by simultaneously trapping two polymers. The scaling relationships and $\theta$ behaviors are well captured. Conformations with large shape anisotropy appearing in charged polymers are clearly depicted. Our theoretical predictions are in quantitative agreement with experimental results reported in the literature.

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Luofu Liu, Chao Duan, Rui Wang. 2024-04-21. A Variational Approach to Trap Macromolecules. https://arxiv.org/abs/2404.13574

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