SBA-15介观相形成过程的耗散粒子动力学模拟  

Dissipative particle dynamics simulation of SBA-15 mesophase formation

作　　者：陈汇勇[1] 吴永标[1] 周碧红[1] 奚红霞[1] 夏启斌[1] 李忠[1] 钱宇[1] 

机构地区：[1]华南理工大学化学与化学工程学院,广东广州510640

出　　处：《化工学报》2009年第8期2024-2030,共7页CIESC Journal

基　　金：国家自然科学基金项目(20536020;20876061);教育部留学回国人员科研启动基金项目;国家高技术研究发展计划项目(2006AA06A310)~~

摘　　要：采用耗散粒子动力学方法(dissipative particle dynamics,DPD),以介孔分子筛SBA-15的合成原料P123/TEOS/H2O为研究体系,模拟了P123/TEOS超分子自组装行为,及剪切力作用下介孔分子筛SBA-15六角介观相的形成过程。结果表明:在水溶液中,P123与TEOS两相能够发生协同作用自组装形成超分子聚集体(胶束),该胶束由疏水的PPO球核、亲水的PEO球壳以及聚集包裹在P123外部的TEOS组成;引入稳恒剪切力后,P123/TEOS超分子聚集体则会逐渐转变成规整的六角结构,并最终形成SBA-15六角介观相,这与实际材料的TEM电镜图片相吻合。可以说,DPD模拟方法是一个研究有序介孔分子筛SBA-15形成机理的有效手段,可为实验合成提供介观层面上的重要信息。此外,还拓展了DPD模拟在超分子自组装介观尺度研究方面的新应用。Dissipative particle dynamics （DPD） method is performed to investigate the surfactant-silica cooperative organization effects in the mesoporous silica SBA-15 formation process, and steady shear is introduced to represent stirring in actual experiment. Simulation results show that uniform spherical supermolecular micelles can be assembled by the cooperation of the two precursors in SBA-15 formation, the template copolymer （P123） and the silica source （TEOS） . The hydrophobic PPO micelle cores play a decisive role in the uniform mesopore formation process of SBA-15, while the hydrophilic PEO micelle coronas interact with the silica matrix to form the micropores upon calcinations. When steady shear introduced into the simulation system, the P123/TEOS super-molecular assembly no longer form spherical micelles, but form cylindrical micelles with hexagonally array, and finally form the structure of SBA- 15. The simulation results proved that the DPD method can exactly describe the surfactant-silica cooperative organization and the SBA-15 mesophase formation process, which is also an effective tool for investigating the formation mechanism of ordered mesoporous silica.

关 键 词：SBA-15 P123 介观相 耗散粒子动力学 超分子自组装 

分 类 号：O611.4[理学—无机化学] O641[理学—化学]