The effects of Lowe-Andersen temperature controlling method on the polymer properties in mesoscopic simulations.
The effects of Lowe-Andersen temperature controlling method on the polymer properties in mesoscopic simulations.
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DOI：
10.1063/1.1860351
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发表时间：
2005-03
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影响因子：
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通讯作者：
Li-Jun Chen;Zhong-yuan Lu;H. Qian;Zesheng Li;Chia-Chung Sun
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作者：
Li-Jun Chen;Zhong-yuan Lu;H. Qian;Zesheng Li;Chia-Chung Sun
Lowe-Andersen（LA）温度控制法[C. P. Lowe，Europys。Lett. 47，145（1999）]应用于一系列介观聚合物模拟，以测试其有效性和效率。该方法是一种替代耗散粒子动力学模拟（DPD）技术，这也是伽利略不变量。该系统具有良好的温度控制性能，并给出了与DPD仿真结果一致的径向分布函数。与其他典型的DPD积分方法进行了比较，结果表明LA方法具有一定的效率。此外，我们将这种方法应用于二嵌段共聚物的微相分离模拟。使用LA方法，我们能够再现所有的结果，从传统的DPD模拟。计算得到的微相结构因子与实验结果基本一致。我们还研究了微相随chiN增加的演化动力学，发现熔池碰撞频率γ并不影响相出现的顺序。虽然恒温器不影响表面张力，但有序-无序转变（ODT）对γ值有些敏感，即，ODT随Gamma的增加而非单调。对动态标度律也进行了检验，表明在不同的Gamma下，该关系都服从Rouse理论。
Lowe-Andersen (LA) temperature controlling method [C. P. Lowe, Europhys. Lett. 47, 145 (1999)] is applied in a series of mesoscopic polymer simulations to test its validity and efficiency. The method is an alternative for dissipative particle dynamics simulation (DPD) technique which is also Galilean invariant. It shows excellent temperature control and gives correct radial distribution function as that from DPD simulation. The efficiency of LA method is compared with other typical DPD integration schemes and is proved to be moderately efficient. Moreover, we apply this approach to diblock copolymer microphase separation simulations. With LA method, we are able to reproduce all the results from the conventional DPD simulations. The calculated structure factors of the microphases are consistent with the experiments. We also study the microphase evolution dynamics with increasing chiN and find that the bath collision frequency Gamma does not affect the order of appearing phases. Although the thermostat does not affect the surface tension, the order-disorder transition (ODT) is somewhat sensitive to the values of Gamma, i.e., the ODT is nonmonotonic with increasing Gamma. The dynamic scaling law is also tested, showing that the relation obeys the Rouse theory with various Gamma.