化学学报 ›› 2000, Vol. 58 ›› Issue (4): 402-406. 上一篇    下一篇

研究论文

对pluronic水溶液介观相分离的理论模拟研究

李有勇;侯廷军;王凯旋;郭森立;徐筱杰   

  1. 北京大学化学与分子工程学院
  • 发布日期:2000-04-15

Theoretical study of the mesoscopic morphology of the pluronics water mixtures

Li Youyong;Hou Tingjun;Wang Kaixuan;Guo Senli;Xu Xiaojie   

  • Published:2000-04-15

用一种新的动力学密度泛函方法(介观动力学)对pluronics(P85)水溶液的介观相分离动力学进行了模拟研究。该方法可以直接给出水溶液体系中不规则三维微观形貌的动力学形成过程。在动力学模拟中热力学参数通过平均场密度泛函方法计算得到,共聚物分子则用高斯链作为模型进行模拟研究。高斯链的最小结构单元是被抽象为键连的株子体,代表实际体系高聚物分子中的一个单体或几个单体。研究了pluronuc水溶液体系的动力学演变历程并讨论了嵌段共聚物中不同组分长短以及共聚物浓度等因素对溶液微观形貌和体系性质的影响。和其它平衡态模拟方法相比较,介观动力学方法可以给出介观相分离的时间演变过程,有助于加深对很多工业加工处理过程和生理过程机理的理解。

关键词: 密度泛函理论, 高斯链, 介观动力学, 聚氧化乙烯, 聚氧化丙烯

A new dynamic density functional method(mesodynamics) was used to simulate microphage separation kinetics of the aqueous solution of the triblock polymer surfactant (ethylene oxide) 27 (propylene oxide) 39 (ethylene oxide)27. We used the method of reference 12 to perform the parameterization. Each polymer chain was substituted by a Gaussian chain. The dynamic evolution process of the system was investigated, which is hard to be determined by experiments now. We discussed the influence of relative block sizes and the concentration of the polymer on the morphology and the property of the mixtures. The simulation results show that the morphology of the pluronic water mixture is sensitive to the length of the PPO chain. The results also indicate that the dynamic evolution process can be divided into two stages.

Key words: NON IONIC SURFACTANTS, POLYETHYLENE OXIDE

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