Synthetic Self-Assembly Strategies and Methods

Alexandra Zamboulis, Olivier Dautel, and Joel J.E. Moreau 

Elaboration of solids under mild reaction conditions has opened the door to the design of a wide variety of useful materials for applications in fields as different as energy, environment, transport, construction, and health. The introduction of the chimie douce approach [1] in materials science allowed the emergence of new synthetic paths to achieve unique materials and structures. Despite the fact that sol-gel chemistry started to develop in the 1960s, it was as early as 1845 that Ebelmen first reported the synthesis of silica [2] noting that upon exposure to humidity a silicic ether transformed into a transparent solid similar to quartz.  

Sol-gel chemistry has allowed to bridge molecular chemistry and materials science. It opened up the way for the synthesis and processing of solid metal oxides under remarkably mild conditions by hydrolysis and condensation of molecular precursors [3]. The path using metal alkoxides as precursors has proved to be particularly adaptable [4]. 

The point we would like to discuss in this chapter is that, importantly, sol-gel chemistry has allowed the concepts of molecular organic and inorganic chemistry together with those of supramolecular and macromolecular chemistry to enter the field of materials science. Therefore, it has allowed the design of new synthetic routes, taking advantage of the kinetic reactivity of the molecular precursors and of the intermolecular interactions that can develop during the formation of the three-dimensional polymeric metal oxide network. 

The Sol-Gel Handbook Synthesis, Characterization, and Applications, First Edition. 

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Relatively few studies on the synthesis of mesoporous alumina have been reported to date [8]. One of the limitations of the reported synthetic strategies is that the rate of hydrolysis (and condensation) reaction of aluminum alkoxide are much faster than that of silicon alkoxide. In this study, we proposed a novel method to prepare bimodal porous aluminas with meso- and macropores with narrow pore size distribution and well-defined pore channels. The fiamewoik of the porous alumina is prepared via a chemical templating method using alkyl caiboxylates. Here, self-assemblied micelles of carboxylic acid were used as a chemical template. Mesoporous aluminas were prepared through carefiil control of the reactants pH, while the procedures are reported elsewhere [9]. 

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