Fundamentals of mesostructuring through evaporation-induced self-assembly
Fundamentals of mesostructuring through evaporation-induced self-assembly
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DOI：
10.1002/adfm.200305036
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发表时间：
2004-04-01
影响因子：
19
通讯作者：
Sanchez, C
中科院分区：
文献类型：
--
作者：
Grosso, D;Cagnol, F;Sanchez, C
这篇文章给出了一个整体的看法，在介观结构的过程中发生的表面模板化的无机材料通过蒸发形成的机制。由于这种制备方法非常适合于通过浸涂、旋涂、浇铸或喷涂来制造薄膜，因此最重要的是对自组装混合有机/无机材料形成期间发生的过程进行一般描述，并考虑所有关键参数。下面的研究是基于最近的工作上的介观组织的二氧化硅薄膜，使用正硅酸乙酯（TEOS）作为无机源和十六烷基三甲基溴化铵（CTAB）作为结构剂，但我们将表明，该方法也可以扩展到其他系统的基础上非二氧化硅氧化物和嵌段共聚物表面活性剂。我们表明，该组织主要取决于膜的化学组成，当它达到可调制的稳态（MSS），其中的无机框架仍然是灵活的，并且在挥发性物质的扩散达到平衡后的组合物是稳定的。这种MSS状态通常在干燥线之后几秒钟达到，并且膜的组成取决于各种参数：环境中的相对蒸气压，蒸发条件和初始溶液中的化学条件。图的纹理，其中稳定的结构是由当地的最小值控制，提出了解释与蒸发引起的介观结构的复杂现象。
This article gives an overall view of the mechanisms involved in the mesostructuring that takes place during the formation of surfactant-templated inorganic materials by evaporation. Since such a method of preparation is well suited to fabricating thin films by dip coating, spin coating, casting, or spraying, it is of paramount interest to draw a general description of the processes occurring during the formation of self-assembled hybrid organic/inorganic materials, taking into account all critical parameters. The following study is based on very recent works on the meso-organization of thin silica films using tetraethylorthosilicate (TEOS) as the inorganic source and cetyltrimethylammonium bromide (CTAB) as the structuring agent, but we will show that the method can also be extended to other systems based on non-silica oxides and block copolymer surfactants. We demonstrate that the organization depends mainly on the chemical composition of the film when it reaches the modulable steady state (MSS), where the inorganic framework is still flexible and the composition is stable after reaching an equilibrium in the diffusion of volatile species. This MSS state is generally attained seconds after the drying line, and the film's composition depends on various parameters: the relative vapor pressures in the environment, the evaporation conditions, and the chemical conditions in the initial solution. Diagrams of textures, in which the stabilized structures are controlled by local minima, are proposed to explain the complex phenomena associated with mesostructuring induced by evaporation.