Order - Disorder in self-assembled mesostructured silica films: A concepts review

Organization of nanomaterials through self-assembly is an important example of disorder to order evolution of nanoscaled systems. Mesoporous materials show an ordered porous structure at the mesoscale (2-50 nm) whose formation is driven by the fast solvent evaporation during processing. An ordered porous topology is achieved in mesoporous thin films by a combination of sol-gel and supramolecular chemistry using a micelle templated self-assembly process. In the last years an increasing number of scientific articles and reviews have been dedicated to the subject because of its interest for basic science and the envisaged applications in several fields. These materials are obtained through a process which needs controlling of several synthesis and processing parameters; they represent an interesting challenge to our capabilities of understanding order-disorder transitions in complex systems. Order in mesoporous silica films is, in fact, connected to the structural organization of pores, to transitions between different types of phases, the presence of well-defined building block units, and structure in the pore walls. We have critically reviewed the concepts behind self-organization in mesoporous silica films by discussing several aspects in which order is involved.