物理化学学报 >> 2011, Vol. 27 >> Issue (05): 1135-1142.doi: 10.3866/PKU.WHXB20110406

软物质 上一篇    下一篇

大离子诱导聚电解质/表面活性剂复合物的解离

刘振海, 尚亚卓, 黄永民, 彭昌军, 刘洪来   

  1. 华东理工大学化学系, 化学工程国家重点实验室, 上海 200237
  • 收稿日期:2010-11-11 修回日期:2011-01-06 发布日期:2011-04-28
  • 通讯作者: 尚亚卓 E-mail:shangyazhuo@ecust.edu.cn
  • 基金资助:

    国家自然科学基金(20706013, 20736002), 长江学者创新团队(IRT0721), 教育部留学回国人员科研启动基金和中央高校基本科研业务费专项资金资助

Disassembly of Polyelectrolyte/Surfactants Complex Induced by Macroions

LIU Zhen-Hai, SHANG Ya-Zhuo, HUANG Yong-Min, PENG Chang-Jun, LIU Hong-Lai   

  1. State Key Laboratory of Chemical Engineering, Department of Chemistry, East China University of Science and Technology, Shanghai 200237, P. R. China
  • Received:2010-11-11 Revised:2011-01-06 Published:2011-04-28
  • Contact: SHANG Ya-Zhuo E-mail:shangyazhuo@ecust.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20706013, 20736002), Creative Team Development Project of Ministry of Education of China (IRT0721), Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry and Fundamental Research Funds for the Central Universities, China.

摘要:

采用分子动力学模拟方法研究了大离子与聚电解质/表面活性剂复合物的相互作用, 考察了大离子的电性、直径、表面电荷、浓度等对其与复合物相互作用的影响. 结果表明, 与聚电解质所带电性相同的大离子对复合物作用不明显, 只有当大离子所带电荷较多时, 才会引导少量表面活性剂从复合物中脱离. 当大离子所带电荷与聚电解质所带电荷电性相反时, 大离子的加入会诱导复合物的解离, 表面活性剂从复合物中释放出来, 甚至导致聚电解质/表面活性剂复合物的完全解离, 从而形成聚电解质/大离子复合物; 大离子所带电荷越多, 诱导作用越明显. 大离子的直径及浓度对其与复合物之间的作用也有很大的影响, 对于所带电荷数相同的大离子而言, 直径越小, 其与复合物的作用越显著, 越容易引导表面活性剂从复合物中解离, 若大离子的表面电荷密度相同, 大离子直径越小, 反而与复合物的作用越弱; 大离子浓度越高, 越易引起复合物的解离, 复合物中聚电解质链上结合的大离子数增多直至饱和, 相应的会出现电荷反转现象.

关键词: 聚电解质, 表面活性剂, 复合物, 解离, 分子动力学模拟

Abstract:

The effects of charge number, diameter, surface charge density as well as concentration of macroions on the structure of a polyelectrolyte/surfactants complex were investigated using coarse- grained molecular dynamics simulation. We found that the macroions that had the same charge as the polyelectrolyte had no obvious effect on the structure of the polyelectrolyte/surfactants complex. However, the macroions with opposite charge to the polyelectrolyte can induce the release of surfactant from the polyelectrolyte and even lead to the complete disassembly of the polyelectrolyte/surfactants complex and the formation of a macroion/polyelectrolyte complex. The induction effect increases with an increase in charge number. For microions with the same charge number, smaller microions were found to cause desorption of the surfactant more easily. However the opposite effect was found for the diameter at a fixed charge density. The concentration of macroions also affects the structure of the complex greatly and the surfactants that are released from the polyelectrolyte increase with the macroion concentration and finally a macroion/polyelectrolyte complex with reversed charges is formed.

Key words: Polyelectrolyte, Surfactant, Complex, Disassembly, Molecular dynamics simulation

MSC2000: 

  • O648