Vol.11 no.3 2019

Research paper : Challenge towards synthesis of non-silica-based hybrid mesoporous materials (T. KIMURA)−119−Synthesiology - English edition Vol.11 No.3 (2018) will become a candidate alternative material. On the other hand, in cases that start with a discovery of a new material (dramatically enhanced function), there is a possibility of technological innovation. However, I all know that there are plenty of technological hurdles that must be overcome before practical application. Depending on how the new material is to be used, even the synthesis method that was rst found may have to be altered. In general, this corresponds to the development of control technology for “composition,” “structure,” and “form” in synthesis research.In a case of materials development in which mesoporous technology is used, materials synthesis is attempted by clarifying the developmental factors that are to be targeted. This is explained in Fig. 7 (bottom). If the performance in demand is clear, some hints may be obtained for candidate composition to achieve that function through surveys of existing research. Limited to the cases in which performance improvement can be expected through structure control (in this research, mainly achieving mesoporosity), I start the development of porosity technology using materials with candidate composition. If the form in which it will be used is set, the process of sample preparation as a lm or powder can be determined. For example, say that one prepares a homogenous precursor solution, particularly a transparent one. In this case, separation of lms and powder is possible only by coating or spray-drying, as the process used for both is solvent evaporation by which precursors for mesoporous materials is made. Therefore, development of structural control and form control can be construed as development of elemental technologies that can be conducted together. In the sense that formation of mesoposority is conducted for selected candidate composition, the composition is not the target of control. In synthesis research for mesoporous materials like this research, it is most important to properly understand the reactivity of raw materials in solution to advance mesoporosity technology.There is another important point in achieving assumed performances to the maximum. In most cases, the precursor materials of mesoporous materials are obtained with inorganic frameworks of amorphous conditions, and it is necessary to crystallize the inorganic frameworks after achieving mesoporosity, if the expected performance is derived from the functional expression of crystalline materials. Since the inorganic framework can be crystallized by heat treatment (ring), additional process is not necessary. As mentioned before, if crystallization goes too far, the mesoporous structure disintegrates in most cases. Therefore, maximizing the crystallized ingredient without losing the effect of mesoporosity will be the aim of material design. Also, ones with larger pore sizes tend to have mesoporous structures that do not disintegrate even with crystallization. In such cases, the merit of “improved dispersibility” is obtained as well as “increased crystallization.” Therefore, it is important to develop a precise synthesis technology by which the performance is maximized through the effects of surface area, crystallization, and dispersibility.5 Future issues and prospectsThe synthesis technology for “non-silica-based hybrid mesoporous materials” that was developed in this research showed major progress and has potential for greatly expanding the compositional control range of ordered mesoporous materials. However, mesoporous aluminum phosphonates, which were synthesized using phosphonic acid bridged with an alkyl group at the start of the research, was collected as powder.[15]-[19] On the other hand, formation of films was the main theme of research for phosphonate compounds bridged with various aromatic compounds that were recently successfully developed.[22] Fortunately, powder Demanded performancePromising compositionStructural controlFabricate technology of mesoporous structureOptimizing compositionComplexing dierent materialsMorphological typePowder/pelletTransparent lmParticle deposition lm・・Morphological controlCompositional control?Evaluation of performance (comparison with existing materials)Performance designIncreasing crystallinityMaintaining porosityInvestigating hierarchical structure・・Deciding morphological typeDiscovery of new materials (technological innovation)Providing developed materials (conrming higher performance)Evaluating performance of material (conrming demanded performance)Improvement of synthetic method (compositional, structural, and morphological controls)Social demand (application development)Fig. 7 Basic guideline for the materials design to develop applications

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