摘要
采用介观动力学(MesoDyn)方法模拟了硅基有序介孔分子筛SBA-15介观相的形成过程,并深入研究了有机模板剂、硅酸物种的电荷效应以及二者之间的电荷匹配相互作用对SBA-15介观相结构的影响。结果表明:当硅酸物种不带电或分配1e正电荷,同时有机模板剂P123的每个EO单元分配0.093e正电荷的时候得到的SBA-15介观组装结构具有较好的六角特性;硅酸物种和有机模板剂之间的电荷匹配相互作用对SBA-15介观组装结构影响很大,带电的硅酸物种促进了有机模板剂形成类液晶相,而质子化的有机模板剂不但使硅酸物种有序化,而且促进了硅酸物种在两相界面的浓缩。模拟研究结果很好地验证和解释了SBA-15的'有机模板剂与硅酸物种之间的协同相互作用'的形成机理。本文的研究提供了一种探索硅基有序介孔分子筛形成机理的新手段,弥补了现阶段实验表征手段的不足,同时也扩展了MesoDyn方法在超分子自组装方面的新应用。
The mesoscopic dynamics （MesoDyn） method was used to investigate the charge effects and charge matching interactions between surfactant and silicate species on the mesophase structure of SBA-15.The simulation results showed that a uniform hexagonal mesophase of SBA-15 was formed when no charge or one unit positive charge was distributed to the silicate species while 0.093 unit positive charges were distributed to each EO unit of the P123 surfactant.Moreover,the charge effects of surfactant and silicate species both had a significant impact on the mesophase structure of SBA-15.On the one hand,the silicate species with positive charges could promote the formation of surfactant liquid crystal phase.On the other hand,the surfactants with some weak charges could not only put the silicate species in order,but also promote the concentration of silicate species on the interface.The simulation results validated and interpreted the ＂surfactant/silicate species cooperative formation mechanism＂ of SBA-15.The MesoDyn method was developed to investigate the formation mechanism of ordered mesoporous molecular sieves.This work could make up for the lack of experimental and characterization technologies.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2010年第3期682-690,共9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)~~
