Relation between the Lower Consolute Boundary and the Structure of Mesoporous Silica Materials

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• 作者：F. Michaux ; J. L. Blin ; M. J. St&eacute ; b&eacute
• 刊名：Langmuir
• 出版年：2008
• 出版时间：February 5, 2008
• 年：2008
• 卷：24
• 期：3
• 页码：1044 - 1052
• 全文大小：235K
• 年卷期：v.24,no.3(February 5, 2008)
• ISSN：1520-5827

文摘

In this study, we have shed some light on the relation between the position of the lower consolute boundary ofvarious nonionic surfactants in water and the structure of the mesoporous silica materials synthesized from thesesurfactants-based systems. In the first part, the lower consolute boundary was shifted by adding salts. Depending onthe features of the phase diagram, we have looked for either a salting out or a salting in effect. Mesoporous materialswere prepared from a micellar solution of the investigated surfactants. Results clearly evidenced that the cooperativeself-assembly mechanism is not favored if the lower consolute boundary is not shifted toward high temperatures.Moreover, the higher the difference between the phase separation temperature and the temperature at which the silicaprecursor is added to the surfactant solution, the better the mesopore ordering is. In the second part, this tendencyhas been confirmed by using a hydrogenated surfactant as additive.