Organic fillers chemical synthesis

Inorganic fillers can be divided into natural and synthetic fillers. The former are obtained by the mechanical or chemical processing of naturally occurring minerals and the latter by chemical synthesis involving not only inorganic but also organic raw materials. 

In our previous papers (refs. 4,5) we described syntheses of VPI-5 using DPA and TBA. Since that time we have been able to crystallize VPI-5 using many other organics such as diisopropylamine, dipentylamine (DPentA), triethanolamine (TEOA), triisopropanolamine (TIPOA), cyclopentyl amine, and cyclohexyl amine at synthesis temperatures from 120 to 150 C. The wide variety of organics able to crystallize VPI-5 suggests further that the organic does not act as a template and from chemical analyses it is clear that it does not act as a space-filler. 

In any case, it is clear that, for its own nature, sol-gel material is suitable for the formation of many different composite materials [207] inorganic and organic polymers, as well as many different kinds of nano-objects possessing effective electrocatalytic properties, can find stable inclusion into a host matrix possessing all the characteristics previously listed. The most simple approach consists of adding the filler to the siliceous matrix after sol-gel formation. However, composite materials can also be obtained by synthesizing the sol-gel film in the presence of the precursor of the filler, e.g., a monomer [227] or a metal complex [228]. The synthesis of the composite material is finalized in a subsequent step, e.g. by a chemical oxidation or reduction, leading to polymer chains or metal nanoparticles, respectively, included inside the sol-gel matrix. 

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