Talc-like hybrids: influence of the synthesis parameters on the polycondensation degree, crystallinity and thermal stability
This study aims to understand how the synthesis parameters (solvent type, synthesis duration, addition of a base and its type, addition of water, pH of the synthesis medium) influence the formation of organic-inorganic hybrids possessing a talc like structure. The materials were synthetized starting from N-[3-(trimethoxysilyl))propyl]ethylenediamine as silicon source. The hybrids were mainly characterized by 29Si solid-state NMR in order to evaluate the condensation degree of the silicon species. The results have shown that the solvent and the synthesis duration do not influence the condensation degree. The addition of water in the synthesis medium induces a strong decrease of the degree of polycondensation of the silicon species. A basic pH of the synthesis medium can also further decrease this parameter. Additional information has been provided by X-Ray diffraction and thermogravimetric analyses; a correlation between the Full Width at Half Maximum and the thermal stability of the hybrids synthetized in presence of different amount of water was enlightened. This funding suggests the possibility to modulate the polycondensation degree of the silicon species by varying only one parameter, thus driving the crystallinity and the thermal stability of the hybrid.