Ordered porous materials

Ihlein, G. et al., Ordered porous materials as media for the organization of matter on the nanoscale, Appl. Organometallic Chem., 12, 305, 1998. 

Davis, M. E. Ordered porous materials for emerging applications, Nature, 2002, 417, 813-821. 

In conclusion, it is clear that the immobilization of peroxidases into ordered porous materials with high surface areas aids the biocatalytic operation in terms of stability and activity in conditions that simulate an industrial process such as high temperature, the presence of organic solvent, and high H202 concentrations. 

The synthesis of ordered mesoporous materials in the past decade greatly expanded the range of ordered porous materials and opened up many new opportunities in the design and applications of materials. Of particular importance is the synthetic methodology that is used for the preparation of these materials. Prior to this, the synthesis of porous materials generally involved the use of individual molecules or hydrated clusters of simple ions. In the synthesis of ordered mesoporous materials, however, it is the assembly of surfactant molecules that directs the condensation of inorganic precursors. 

M.E. Davis, Ordered Porous Materials for Emerging Applications , Nature, 417, 813 (2002)... 

Three-dimensionally ordered porous materials have been applied to electrochemical energy conversion systems, such as Uthium battery, fuel cell, and electrochanical double layer capacitor. Based on this technique, functional materials for other applications can be produced. The advantages of three-dimensionally ordered materials are based on micro or nano size ordered pores. 

Such a structure provides highly uniform porous nature. This is the most important point. For example, the uniform reaction may occur in all the pores. A higher mechanical strength may be realized from ordered stmcture. Especially, two-dimensional electrochemical reactions are strongly enhanced by using three-dimensionally ordered porous materials, as mentioned above. In other words, two-dimensional electrochemical reactions are converted to pseudo three-dimensional ones. This procedure is useful for practical applications. Presently, preparation of three-dimensionally ordered macroporous materials is not so easy due to low mechanical strength and the presence of minor defects. More extensive research will be carried out in the near future. 

In many cases it is necessary to synthesize porous materials in a well-defined preordered shape or within confined geometries, which introduces a pathway to fabricate hierarchically ordered porous materials. The techniques mentioned above have been shown to be capable of producing structured and well-ordered templates [61] within capillaries [50], thin plates [62], micromolds [63], or photoresist patterns [64,65]. Spatial adjustment of the surface functionality on the substrate and its wetting properties can yield patterned colloidal films [66,67]. Finally, confining the particle dispersion itself by printing techniques produces micropatterned arrays [68]. This was also shown to work without the necessity of preceding surface patterning steps [69]. 

As outlined in the Introduction, porous materials can be classified into materials which consist of microporous (below 2 nm), mesoporous (2-50 nm), and macroporous (larger than 50 nm) channels and voids. Networks, which comprise various classes of pores with characteristically different dimensions, are termed hierarchical according to the discussion above. The controlled synthesis of hierarchically ordered porous materials is highly desirable and has attracted much attention during the last decade. The search for such syn-... 

Humans are fascinated by the beauty of naturally and artificially ordered materials, and chemists are attracted by the beauty of ordered porous materials. Ordered porous materials offer a wide variety of applications based on properties specific to pore size and arrangement. Material properties are also dominated by chemical and physical properties of the solid matrix. 

We have selected ordered porous crystalline transition metal oxides that meet all three of the following criteria. The first criterion is that they are ordered porous materials, and that ordered pores were observed by transmission electron microscopy (TEM) or scanning electron... 

MCM-n Mobil composition of matter, ordered porous materials with different structures n — 22, 49, 58, 69 (zeolites) k = 41, 48 (mesoporous materials)... 

SAPO-n porous silicoaluminophosphate, n — 4, 5, 18, 34, 37, 40, 44 SBA Santa Barbara ordered porous materials with different structures ssz -n Standard Oil Synthetic Zeolite porous alumosilicates with different structures (SSZ-13, CHA SSZ-24, API)... 

Templated Methods for the Preparation of Ordered Porous Materials... 

---