Noronha Lisboa-Filho, PauloPauloNoronha Lisboa-FilhoYendry, Corrales UrenaCorrales UrenaYendryRosifini Alves Rezende, Maria CristinaMaria CristinaRosifini Alves RezendeRischka, KlausKlausRischka2023-12-142023-12-142015https://publica.fraunhofer.de/handle/publica/457974Zinc oxide nanoparticles were synthesized and dispersed in the polystyrene marix using a sonochemical method. Furthermore, the ultrasonic degradation of polystyrene (PS) was investigated at different polymer concentrations in solvent/aqueous media previously to the particles synthesis. The variation in intrinsic viscosity and molecular weight distribution (MWD) curves of polystyrene samples were monitored by size exclusion chromatography and intrinsic solution viscosity measurements. It was found that reduction in the weight average molecular weight (Mw) is strongly depended on the concentration of the polymer in organic solvent and sonication time; the degradation decreases in more concentrated solutions and increases with the ultrasound time irradiation. Scanning electron micrographs showed particles with flower morphology with an average size of 400 nm and hexagonal-phase. Antibacterial activity of the ZnO/PS films was also tested against bacteria Escherichia coli (Gram negative); evaluating the bacterial growth inhibition after 20 h on contact with the surface of the films. The results indicate that the growth rate of bacteria is suppressed in the solution in contact with the ZnO/PS film compared with the PS films. This study showed a potential use of ZnO/PS films like antibacterial coating, especially against Escherichia coli. The inflammatory tissue response of this material was also explored. Forty-eight male rats of the Wistar strain (~45 days) were used. Polyethylene tubes containing physiologic solution and experimental material were divided into (n=8) Group I and Group II, respectively. The inflammatory response of subcutaneous tissue was analyzed after 7, 14 and 30 days. After the experimental periods, animals were euthanized and tissues containing the implants were removed and prepared using conventional histological procedures. The results showed normal inflammatory response to the foreign material in contact with rat soft tissue.enconference paper