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.
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 configurationof 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.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2014年第5期811-820,共10页
Acta Physico-Chimica Sinica
基金
国家自然科学基金(51125032
91334203)
中央高校科研基本业务费资助项目~~
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
Gemini surfactant
Extracellular polymeric substance
Polyelectrolyte
Hydrophobic or hydrophilic performance
Coarse-grained
Molecular dynamics simulation
Sludge dewatering performance
