Virtual experimentation of atomistic entangled polyethylene melts undergoing planar elongational flow revealed an amazingly detailed depiction of individual macromolecular dynamics and the resulting effect on bistable configurational states. A clear coil-stretch transition was evident, in much the same form as first envisioned by de Gennes for dilute solutions of high polymers, resulting in an associated hysteresis in the configurational flow profile over the range of strain rates predicted by theory. Simulations conducted at steady state revealed bimodal distribution functions, in which equilibrium configurational states were simultaneously populated by relatively coiled and stretched molecules which could transition from one conformational mode to the other over a relatively long time scale at critical values of strain rates. The implication of such behavior points to a double-well conformational free energy potential with an activation barrier between the two configurational minima.

中文翻译：

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交流：缠结的聚合物熔体的平面伸长流动中的线圈-拉伸转变

对原子纠缠的聚乙烯熔体进行平面伸长流动的虚拟实验揭示了单个大分子动力学的惊人详细描述，以及对双稳态构型状态的影响。明显的线圈-拉伸过渡清晰可见，其形式与de Gennes最初设想的高聚物稀溶液的形式基本相同，导致在理论上预测的应变速率范围内，结构流动曲线具有相关的滞后现象。在稳态下进行的模拟揭示了双峰分布函数，其中平衡构型态同时由相对卷曲和拉伸的分子填充，这些分子在相对应的应变速率临界值下可以在较长的时间内从一种构型转变为另一种构型。