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1091-專題演講-1100106-張正宏（交大物研所）
演講活動
張貼人：李明芳 ╱ 公告日期：2020-08-18|
Time：1100106 (Wed.) 14:20~16:20
Speaker：Prof.張正宏(CHANG, Cheng-Hung)
國立交通大學物理研究所/Institute of Physics, National Chiao Tung University
Title：Chemical potential formalism for entropic forces of confined polymers
Abstract：In this talk, we will introduce an entropic force formula for partly confined polymers and demonstrate its mathematical equivalence with the well-known chemical potential formula for solutions. It leads to an interesting cross-disciplinary correspondence between polymer physics, granular chains, and chemistry. In analytical studies, the magnitudes of the recoiling, tension, and drift entropic forces are derived for 2D strips, 3D tubes, and 3D slits, with both hard and soft boundaries. In numerical experiments, the force magnitudes extracted by the Jarzynski equality and a recursion formula highly coincide with those obtained from the analytical study. With this formalism, the strengths of various polymer entropic forces are systematically evaluated for different polymers and confinements. Remarkably, the result clarifies the force magnitudes inferred in several recent granular and polymer experiments, including the confined granular chains on a vibrating platform and DNA recoiling and tug-of-war in nanochannels, nanopillar arrays, and nanoslits. More generally, it predicts the yet-unknown force strengths in a variety of biological confined polymers and polymers in single-molecule or microfluidic experiments. According to this analysis, 20 pN seems to be close to the maximum entropic force one can observe in nature for a recoiling polymer.
Reference: H.-Q. Xie & C.-H. Chang, Chemical potential formalism for polymer entropic forces, Communications Physics 2, 24 (2019). https://rdcu.be/bo2VB Place：B101, Gongquan Campuses, NTNU
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最後修改時間：2021-01-04 AM 8:34
