Hybrid inorganic-organic nanocomposites were synthesized in order to subsequently generate silicon nitride by carbothermal nitridation. We intended to obtain in this manner an extraordinary ceramic material, with important characteristics: thermal resistance over 1400 °C, small dilation modulus and reduced friction coefficient. The radical polymerization of acrylonitrile took place in nanoporous silica, by the initiation with azoizobutirodinitrile (AIBN). It was intended to enhance the homogeneity between constitutive parts by a larger period of imbibition of the silica with the monomer, through a better absorption capacity of the silica for the monomer and by the application of ultrasonication technique. In the work different silica samples were used, in different polymerization conditions, by varying the monomer imbibition period and the ultrasonication time. The nanoporous silica and the obtained nanocomposites were analyzed by various methods: BET, DTA, DSC, TEM, SEM, FTIR and XRD. The following conclusions were drawn: ultrasonication is a better way to homogenize the constitutive parts of the hybrid materials; the structural homogeneity of nanocomposites is influenced by the purity of samples; a great importance has also the nature of the mineral acid used for the acid attack of the serpentinite.
