Hybrid organic-inorganic materials: from self-organization to nanocrystals

The advantage of inorganic–organic hybrids is that they can combine the properties of organic and inorganic components in one material; this provides the opportunity to invent new materials with a large spectrum properties. The synthesis of hybrid materials through the precise structure control from the molecular to the macroscopic level is a key point for a variety of applications.3-Glycidoxypropyltrimethoxysilane (GPTMS) is one of the most common precursors for the preparation of hybrid materials. Important applications have been reported for these materials, for instance as protective layers, antiscratch coatings, anticorrosion coatings and restoration materials; in the photonic field, as optical waveguides, or second order non-linear optical materials.Hybrids materials commonly synthesized as amorphous, only in few cases hybrid crystals can be obtained; but the practical application as photonics, require optically transparent films.In the present work we have extended the formation of hybrid crystals to thin films. This represents an important result, several requirements have to be fulfilled, such as optical transparency, and controlling of the properties that are added by nanocrystals.We have investigated the reactions in highly basic conditions of GPTMS by different techniques. We have presented the possible reaction pathways whose control is necessary to obtain a hybrid material of tunable properties. We have varied some key processingparameters such as aging time and aging temperature, and we have studied how theyaffect the self-organization process, the silica condensation and epoxy opening reactions.Finally we have demonstrate that the hybrid films prepared by sol-gel method employed GPTMS as precursors in basic condition can be used for the microfabrication and this open the route to develop new functional materials.