物理化学学报 >> 2014, Vol. 30 >> Issue (5): 811-820.doi: 10.3866/PKU.WHXB201403201

理论与计算化学 上一篇    下一篇

表面活性剂对污泥脱水性能影响的机理研究:Gemini表面活性剂与聚电解质相互作用的分子动力学模拟

吕文杰1, 胡耀峰2, 詹必才2, 刘振海2, 尚亚卓2, 汪华林1, 刘洪来2   

  1. 1 华东理工大学国家环境保护化工过程环境风险评价与控制重点实验室, 上海200237;
    2 华东理工大学化学工程联合国家重点实验室, 化学系, 上海200237
  • 收稿日期:2014-02-18 修回日期:2014-03-19 发布日期:2014-04-25
  • 通讯作者: 汪华林 E-mail:wanghl@ecust.edu.cn
  • 基金资助:

    国家自然科学基金(51125032,91334203)和中央高校科研基本业务费资助项目

Study on Mechanism of Surfactant Influencing on Sludge Dewatering Performance:Molecular Dynamics Simulations of the Interaction between Gemini Surfactant and Polyelectrolyte

LÜ Wen-Jie1, HU Yao-Feng2, ZHAN Bi-Cai2, LIU Zhen-Hai2, SHANG Ya-Zhuo2, WANG Hua-Lin1, LIU Hong-Lai2   

  1. 1 State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, P. R. China;
    2 State Key Laboratory of Chemical Engineering and Department of Chemistry, East China University of Science and Technology, Shanghai 200237, P. R. China
  • Received:2014-02-18 Revised:2014-03-19 Published:2014-04-25
  • Contact: WANG Hua-Lin E-mail:wanghl@ecust.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51125032, 91334203) and Fundamental Research Funds for the Central Universities of China.

摘要:

表面活性剂可以与污泥表面的胞外聚合物(EPS)吸附形成胶束,释放出自由水和结合水,从而达到改善污泥脱水性能的目的. 本文采用粗粒化的分子动力学模拟方法,研究了Gemini 表面活性剂与EPS形成复合物的过程和结构. 聚电解质链的亲疏水性对吸附过程有显著影响,亲水聚电解质链与Gemini 表面活性剂吸附的主要驱动力为静电吸引,Gemini 表面活性剂头基吸附在链上,尾链朝向溶剂;疏水聚电解质链与Gemini 表面活性剂吸附过程由静电作用与疏水作用共同促进,Gemini 表面活性剂以平行于聚电解质链的构型存在.Gemini 表面活性剂联结基团长度对吸附过程的影响甚微;聚电解质链的电荷密度对亲水聚电解质链的吸附产生协同作用,对疏水聚电解质链的吸附不产生作用.

关键词: Gemini表面活性剂, 胞外聚合物, 聚电解质, 亲疏水性, 粗粒化, 分子动力学模拟, 污泥脱水性能

Abstract:

Surfactants can be adsorbed with extracellular polymeric substances (EPS) to form micelles with the release of both free and bound water molecules, and this process could be used to improve the performance of the sludge dewatering process. In this paper, coarse-grained molecular dynamics (MD) simulations were adopted to study the formation and structure of complexes resulting from the mixing of a Gemini surfactant and EPS. The hydrophobic or hydrophilic performance of the polyelectrolyte had a significant impact on the adsorption process. The main driving force for adsorption between the hydrophilic polyelectrolyte and the Gemini surfactant was electrostatic attraction, where the head group of the Gemini surfactant was adsorbed onto the chain with the tail chain pointing towards the solvent. The adsorption process between the hydrophobic polyelectrolyte and the Gemini surfactant was influenced by both electrostatic and hydrophobic effects, with the Gemini surfactant being oriented parallel to the configuration of the polyelectrolyte chain. The coupling group length of the Gemini surfactant had very little influence on the adsorption process. Variations in the charge density of the polyelectrolyte chain aided the adsorption of the hydrophilic polyelectrolyte, but had no impact on the adsorption of the hydrophobic polyelectrolyte.

Key words: Gemini surfactant, Extracellular polymeric substance, Polyelectrolyte, Hydrophobic or hydrophilic performance, Coarse-grained, Molecular dynamics simulation, Sludge dewatering performance

MSC2000: 

  • O647