Hybrid advanced materials and the effect of Zirconium on synthesis and properties

Organic-inorganic hybrid materials are significantly important materials due to their peculiar properties. These properties come from a unique combination of the properties of the base components.

Sol-gel is the most common process used to prepare these hybrid materials. It is a low temperature process that gives rise to higher purity and homogeneity when compared with other methods. An important part of the process is the use of metallic alkoxide precursors that promote the crosslinking of the inorganic network and catalyze the hydrolysis-condensation reactions.

In this work, published under AZojomo* (OARS)**, by Lucía Téllez, Juan Rubio, Miguel A. Valenzuela, Fausto Rubio and José Luís Oteo from Instituto Politécnico Nacional-ESIQIE and Instituto de Cerámica y Vidrio-Consejo Superior de Investigaciones Científicas/Kelsen, various hybrid materials were prepared using TEOS and zirconium tetrapropoxide (TPOZ) as the inorganic network precursors and polydimethylsiloxane (PDMS) as the organic component. The processing iof the hybrid materials involved hydrolysis and polycondensation reactions. The effect of TPOZ concentration on structure and texture of the formed materials was studied, maintaining the other synthesis parameters constant.

In all cases monophasic and monolithic xerogels were obtained. Using analysis techniques such as XRD, SEM, N2 adsorption and FTIR, the researchers found that by increasing the amount of TPOZ, gelling times increased. The final hybrid materials were amorphous and mainly mesoporous. Pore diameters varied widely. The porosity was also found to decrease with higher concentrations of TPOZ. The addition of TPOZ to the mixture reaction was also found to significantly affect the texture and microstructure of the final siloxane-zirconia hybrid materials.