Surfactant-inorganic interactions materials

The coulombic surfactant-inorganic (S-I) interaction was the first interaction used in the synthesis of mesoporous MCM silica materials. Likewise, early efforts for the synthesis of mesoporous TM oxides utilized the coulombic interaction as the primary S-I interaction. In these studies, cetyltrimethylammonium bromide (CTABr) as a cationic surfectant and sodium dodecyl sulfate (SDS) as an anionic... 

Results reported in Table I show that the presence of both a phosphonium salt and of a porous support like silica gel are important when 1-bromobutane is allowed to flow in the absence of a catalyst through ground potassium iodide, no 1-iodobutane is pratically obtained on the contrary, the conversion obtained in the presence of potassium iodide + silica gel clearly shows that the inorganic porous material plays the role of a solid solvent and actives iodide anion by interactions which diminish the bond strength of the K I ion pair. Furthermore catalytic amounts of the phosphonium salt lead to higher conversion while the presence of the anionic surfactant sodium laurylsulphate (NaLS) on the surface of silica gel does not yield different results from those obtained with silica gel alone. 

Many studies that have focused on the formation mechanism of various types of templated mesoporous materials have been summarized in a number of recent reviews,46 9 and it is still an ongoing topic of research.50 51 Here, we want to recapitulate only very briefly the useful interaction classification scheme between the surfactants (S) and the inorganic species (I), which was suggested by Huo et al.52,53... 

The synthesis procedure for mesoporous material is simple, and synthesis parameters can be controlled easily. The simple procedure does not mean that the reactions or interactions among reactants in the synthesis system are simple. Many complicated reactions, interactions, and assemblies occur in the mesoporous material synthesis system. The synthesis involves three main components Inorganic species for the formation of the inorganic wall template (surfactant in most cases) whose assembly will guide the formation of mesophase the reaction media (solvent). Figure 8.3 shows the interactions between the three main components.[59] These interactions play the key roles during synthesis. The surfactant molecules in the solution will self-assemble into a micelle or liquid-crystal phase of course, various factors can affect the assembly process,... 

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