**5. Conclusion**

The simultaneous intercalation of DDA and TEOS into H+-titanosilicate interlayers and subsequent intragallery DDA-catalyzed hydrolysis of TEOS resulted in mesoporous silicapillared H+-titanosilicate (SPT) derivatives. These derivatives exhibited refractions corresponding to a basal spacing of 4.16–4.32 nm, a uniform pore size of 2.8–3.4 nm and large surface areas of 535–618 m2/g. The structural and physical properties of SPT derivatives exhibited excellent thermal resistance, i.e., they remained stable after heating for 5 h at 700 oC in air. Our results indicate that DDA plays a decisive role in pore formation, because it acts as a base catalyst and as a micelle-like template during the hydrolysis of TEOS. In particular, the rapid hydrolysis of TEOS in water controls TEOS outflow from interlayers and contributes to the formation of firm silica-pillars.

Our results show that intercalation and silylation proceeded more effectively by the evaporation of solvents than by filtration and drying. This evaporation process should be a very efficient method for the intercalation and silylation of silane coupling agents into layered compounds and organic–inorganic materials.

### **Author details**

258 Ion Exchange Technologies

titanosilicate.

**5. Conclusion** 

promising potential oxidation catalysts.

demonstrated that the assembly of hexagonal mesoporous metal oxides can also be achieved by hydrogen bonding between neutral amine and TEOS. In porous materials formed by this gallery-templated reaction, specific surface areas are composed of the surfaces of micropores, where pore walls act as pillars and mesopores. Therefore, the lateral spacing between pillars in conventional pillared layered materials is not the sole contributor to increased microporosity.

**Figure 17.** Schematic representation of the intercalation and silylation of DDA and OTES for H+-

SPT derivatives exhibit a broad pore size distribution as compared with MCM-41. Furthermore, they offer new opportunities for the rational design of heterogeneous catalyst systems because of their complementary chemical functionality, thermal stability, and stable pore size distribution to the small mesopore range (1.0–2.0 nm). In addition, the existence of five-coordinated titanium(V) in the interlayer surfaces of SPT derivatives makes then

The simultaneous intercalation of DDA and TEOS into H+-titanosilicate interlayers and subsequent intragallery DDA-catalyzed hydrolysis of TEOS resulted in mesoporous silicapillared H+-titanosilicate (SPT) derivatives. These derivatives exhibited refractions corresponding to a basal spacing of 4.16–4.32 nm, a uniform pore size of 2.8–3.4 nm and large surface areas of 535–618 m2/g. The structural and physical properties of SPT derivatives exhibited excellent thermal resistance, i.e., they remained stable after heating for 5 h at 700 oC in air. Our results indicate that DDA plays a decisive role in pore formation, because it acts as a base catalyst and as a micelle-like template during the hydrolysis of TEOS. In particular, the rapid hydrolysis of TEOS in water controls TEOS outflow from

Our results show that intercalation and silylation proceeded more effectively by the evaporation of solvents than by filtration and drying. This evaporation process should be a

interlayers and contributes to the formation of firm silica-pillars.

Kyeong-Won Park *Department of Chemistry and Research Institute of Natural Science, Gyeongsang National University, Republic of Korea* 

### **6. References**

