Globule-stretch transition of a self-attracting chain in the repulsive active particle bath
Globule-stretch transition of a self-attracting chain in the repulsive active particle bath
复制标题
排斥活性粒子浴中自吸引链的球体拉伸转变
DOI：
10.1039/c8cp05976d
复制
发表时间：
2019
影响因子：
3.3
通讯作者：
Ma Yu qiang
中科院分区：
文献类型：
--
作者：
Xia Yi qi;Tian Wen de;Chen Kang;Ma Yu qiang
在实验中，通常通过调节pH、温度、单分子作用力或剪切场来操纵链结构的折叠和展开。在这里，我们进行布朗动力学模拟来探索自推进粒子悬浮(SPPs)中单个自吸引链的行为。随着推进力的增大，链的球状-拉伸(G-S)转变是由于表面等离子体激元的扰动增强而发生的。观察到了SPP在低和高转动扩散速率范围内的两种不同的转变机制：低速率剪切诱导拉伸和高速率碰撞诱导熔化。G-S和S-G(拉伸球)曲线在低速率时形成滞后环，而在高速率下合并。此外，我们还发现两种竞争效应导致了G-S跃迁对SPP密度的非单调依赖。我们的结果提出了一种通过利用活化剂来操纵(生物)聚合物折叠和解折叠的替代方法。
Folding and unfolding of a chain structure are often manipulated in experiments by tuning the pH, temperature, single-molecule forces or shear fields. Here, we carry out Brownian dynamics simulations to explore the behavior of a single self-attracting chain in a suspension of self-propelling particles (SPPs). As the propelling force increases, the globule–stretch (G–S) transition of the chain occurs due to the enhanced disturbance from the SPPs. Two distinct mechanisms of the transition in the limits of low and high rotational diffusion rates of SPPs have been observed: shear-induced stretching at a low rate and collision-induced melting at a high rate. The G–S and S–G (stretch–globule) curves form a hysteresis loop at the low rate, while they merge at the high rate. Besides, we find that two competing effects result in a non-monotonic dependence of the G–S transition on SPP density at the low rate. Our results suggest an alternative approach to manipulating the folding and unfolding of (bio)polymers by utilizing active agents.