CARMEN GAIDAU, MADALINA IGNAT, OVIDIU IORDACHE, LAURA MADALINA POPESCU, ROXANA MIOARA PITICESCU, LIA MARA DITU, MARCEL IONESCU ZNO NANOPARTICLES FOR ANTIMICROBIAL TREATMENT OF LEATHER SURFACE The paper presents the antimicrobial performances of leather surfaces treated with ZnO nanoparticles as alternative to the use of volatile organic biocide materials. The hydrothermal synthesis of ZnO nanoparticles is described as an efficient and easy to control method compared to sol-gel methods. The characterization of crystallite morphology and size were measured by XRD, the nanopowder particles were assessed by TEM and the dispersion stability in water and in film forming polymers by dynamic light scattering (DLS). The ZnO nanoparticles were uniformly dispersed on leather surface by conventional technologies based on sprayed layers and were available for direct contact with bacteria and fungi. The treated leather surfaces were tested according to adapted diffusion standard methods and proved sensitivity against bacteria and resistance to fungi. The modification of dynamic contact angle of water on leather surface exposed to UV and visible light irradiation confirmed the photocatalytic generation of oxygen reactive species attributed to antimicrobial efficiency.