Anionic surfactant templating method

In basic solution (pH >10), the silicate ion is anionic. The simplest method is the use of a cation template (e.g., cationic surfactant) to organize these silicate ions. This interaction (synthesis pathway), S I, was applied in the classical synthesis of mesoporous silica in basic media. 

Recently, soft template method has been used for the fabrication of various morphologies of polymer nanomaterials. There are several soft templates such as surfactant, liquid crystalline polymer, cyclo dextrin, and functionalized polymer [100,101,116-122]. Among them, surfactants, which imply cationic, anionic and non-ionic amphiphiles, are mostly used for the for-... 

A more reliable method to control the dimensions of hollow silica particles can be achieved using molecular assemblies, such as micelles and vesicles, as soft templates. For example, hollow silica particles of a controlled diameter (60-120 nm) were obtained using unilamellar vesicles consisting of mixtures of cationic and anionic surfactants [10]. The key point is that these vesicles are stable under the conditions for acid-catalyzed hydrolysis and polycondensation of... 

Zeolitic structures with pore sizes of 2000 to 10000 pm are known as mesoporous solids, and can be formed by a method known as liquid crystal templating (LCT). The combination of a suitable cationic surfactant together with silicate anions form arrays of rod-like surfactant micelles (Figure 3.7) surrounded by a polymeric siliceous framework. On calcination the mesoporous structure is formed. 

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