Leibniz-Institut für Polymerforschung Dresden, Hohe Strasse 6, 01069 Dresden, Germany.
J Chem Phys. 2013 Mar 7;138(9):094902. doi: 10.1063/1.4792201.
We use the bond fluctuation model with explicit solvent to study single polymer chains under poor solvent conditions. Static and dynamic properties of the bond fluctuation model with explicit solvent are compared with the implicit solvent model, and the Θ-temperatures are determined for both solvent models. We show that even in the very poor solvent regime, dynamics is not frozen for the explicit solvent model. We investigate some aspects of the structure of a single collapsed globule and show that rather large chain lengths are necessary to reach the scaling regime of a dense sphere. The force-extension curve of a single polymer chain under poor solvent conditions in the fixed end-to-end distance ensemble is analyzed. We find that the transition of the tadpole conformation to the stretched chain conformation is rather smooth because of fluctuation effects, which is in agreement with recent experimental results.
我们使用带显式溶剂的键浮动模型研究不良溶剂条件下的单链聚合物。将显式溶剂键浮动模型的静态和动态特性与隐式溶剂模型进行了比较,并确定了两种溶剂模型的Θ温度。我们表明,即使在非常不良的溶剂条件下,显式溶剂模型的动力学也不会冻结。我们研究了单个折叠球状物的某些结构方面,并表明需要相当大的链长才能达到密集球体的标度区域。在固定的末端到末端距离系综下,研究了不良溶剂条件下单链聚合物的力-伸长曲线。我们发现,由于波动效应,豆荚构象向伸展链构象的转变相当平滑,这与最近的实验结果一致。