Eisenstecken Thomas, Gompper Gerhard, Winkler Roland G
Theoretical Soft Matter and Biophysics, Institute of Complex Systems and Institute for Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich, Germany.
Polymers (Basel). 2016 Aug 12;8(8):304. doi: 10.3390/polym8080304.
The conformational properties of flexible and semiflexible polymers exposed to active noise are studied theoretically. The noise may originate from the interaction of the polymer with surrounding active (Brownian) particles or from the inherent motion of the polymer itself, which may be composed of active Brownian particles. In the latter case, the respective monomers are independently propelled in directions changing diffusively. For the description of the polymer, we adopt the continuous Gaussian semiflexible polymer model. Specifically, the finite polymer extensibility is taken into account, which turns out to be essential for the polymer conformations. Our analytical calculations predict a strong dependence of the relaxation times on the activity. In particular, semiflexible polymers exhibit a crossover from a bending elasticity-dominated dynamics to the flexible polymer dynamics with increasing activity. This leads to a significant activity-induced polymer shrinkage over a large range of self-propulsion velocities. For large activities, the polymers swell and their extension becomes comparable to the contour length. The scaling properties of the mean square end-to-end distance with respect to the polymer length and monomer activity are discussed.
理论上研究了暴露于有源噪声下的柔性和半柔性聚合物的构象特性。噪声可能源于聚合物与周围有源（布朗）粒子的相互作用，也可能源于聚合物本身的固有运动，聚合物本身可能由有源布朗粒子组成。在后一种情况下，各个单体在扩散变化的方向上独立推进。为了描述聚合物，我们采用连续高斯半柔性聚合物模型。具体来说，考虑了有限的聚合物可扩展性，这对聚合物构象至关重要。我们的解析计算预测弛豫时间强烈依赖于活性。特别是，随着活性增加，半柔性聚合物表现出从弯曲弹性主导的动力学向柔性聚合物动力学的转变。这导致在大范围的自推进速度下，活性诱导的聚合物显著收缩。对于大活性，聚合物膨胀，其伸长变得与轮廓长度相当。讨论了均方端到端距离相对于聚合物长度和单体活性的标度性质。
