HYBRID MATERIALS PREPARED BY IONIZING RADIATION FOR CONSOLIDATION AND PRESERVATION OF ROMAN MOSAICS
PDMS-based ormosils with biocide activity were prepared and functionalized by gamma irradiation, aiming for application in the conservation of Roman mosaics from Conimbriga archeological site. Six different batches of PDMS-TEOS-ZrPO hybrid materials (HMs’) were prepared having attention to the variety and composition of the native materials already studied. Mosaics bioburden were also partially identified and used in the HMs’ biocide assays. Materials revealed to be compact and homogeneous with a smooth surface, transparent, monolithic and amorphous with a thermal resistance up to 350°C. All HM’s proved to be hydrophobic with the contact angle varying from 95 to 115°C. Biocide activity of HMs’ was tested with the most dangerous and resistant microorganisms found in Roman mosaics.: HMs’ with high content in ZrPO (20% wt) showed biostatic activity against Staphylococcus capitis capitis (Gram+), sporulated bacilli (Gram+) and fungi Aspergellius fumigatos (Gram+), without evidence of ionic migration (Zr) to the surrounding medium.