标题： 动态蒙特卡罗研究平衡聚合物：静态性质 显示英文标题

标题： Dynamical Monte Carlo Study of Equilibrium Polymers : Static Properties

摘要： 我们报告了在良好溶剂中无环自组装平衡聚合物（EP）的广泛动力蒙特卡罗研究结果。 （这被认为是一个巨大的表面活性剂胶束的良好模型。） 使用一种新算法，我们能够有效地描述静态和动态特性，其中平均链长$\Lav$与实验室实验中的值有效可比（最多5000个单体，甚至在高聚合物密度下）。 我们采样的断裂能高达$E/k_BT=15$，覆盖近三个数量级的单体密度$\phi$，并呈现从稀释区域的膨胀EP链到密集熔融系统的详细交叉研究。 证实最近的理论预测，发现平均链长按$\Lav \propto \phi^\alpha \exp(\delta E)$的方式缩放，其中指数在稀释和半稀释极限下分别接近$\alpha_d=\delta_d=1/(1+\gamma) \approx 0.46$和$\alpha_s = 1/2 [1+(\gamma-1)/(\nu d -1)] \approx 0.6, \delta_s=1/2$。 链长分布在稀释极限下由 Schulz-Zimm 分布$\cN(s)\approx s^{\gamma-1} \exp(-s)$定性描述，其中标度变量是$s=\gamma L/\Lav$。 这些模拟的非常大的尺寸也允许准确确定自避行走的奇异性指数$\gamma \approx 1.165 \pm 0.01$。 ....... 详细讨论了有限尺寸效应。 显示英文摘要

摘要： We report results of extensive Dynamical Monte Carlo investigations on self-assembled Equilibrium Polymers (EP) without loops in good solvent. (This is thought to provide a good model of giant surfactant micelles.) Using a novel algorithm we are able to describe efficiently both static and dynamic properties of systems in which the mean chain length $\Lav$ is effectively comparable to that of laboratory experiments (up to 5000 monomers, even at high polymer densities). We sample up to scission energies of $E/k_BT=15$ over nearly three orders of magnitude in monomer density $\phi$, and present a detailed crossover study ranging from swollen EP chains in the dilute regime up to dense molten systems. Confirming recent theoretical predictions, the mean-chain length is found to scale as $\Lav \propto \phi^\alpha \exp(\delta E)$ where the exponents approach $\alpha_d=\delta_d=1/(1+\gamma) \approx 0.46$ and $\alpha_s = 1/2 [1+(\gamma-1)/(\nu d -1)] \approx 0.6, \delta_s=1/2$ in the dilute and semidilute limits respectively. The chain length distribution is qualitatively well described in the dilute limit by the Schulz-Zimm distribution $\cN(s)\approx s^{\gamma-1} \exp(-s)$ where the scaling variable is $s=\gamma L/\Lav$. The very large size of these simulations allows also an accurate determination of the self-avoiding walk susceptibility exponent $\gamma \approx 1.165 \pm 0.01$. ....... Finite-size effects are discussed in detail.