Incorporation of Silver Nanoparticles in Film Forming Materials for Long Term Antimicrobial Action

In crowded public areas (hospitals, airports, railway stations, universities, schools, etc.), surfaces of the materials are exposed to microorganisms. These microorganisms can live both in planktonic and biofilm (colonies of microorganisms) being responsible for the transmission of different infections from human to human. Because of that, the antimicrobial effect is an additional function of film-forming materials. The innovation of these types of materials consists both in choosing and stabilizing the active substance in the polymeric material and in the microbial control. Usage of the AgNPs as active substance induces morphological changes in the structure of the film-forming material, a chemical resistance and an antimicrobial efficacy for a long time. The antimicrobial properties of the new materials reduce the consumption of disinfectants and the number of washing cycles which implicitly leads to reduced maintenance costs. The influence of the AgNPs on the morphology, structure and properties of the material coatings was investigated by EDX, SEM and SPM. The antifungal activity of the film-forming materials was investigated onto 12 cultures of mushrooms. Silver nanoparticles can prevent the formation of biofilms through the killing of the fungus and of the bacteria (both gram-positive and gram-negative) that are present on the surface of materials. Materials coatings were applied in a medical unit and after 12 months from application, it was found that neither morphology or structure nor the antifungal or the antibacterial properties have undergone significant changes. Based on these results it is considered that the film-forming materials based on silver nanoparticles could be used to inhibit the development of micro-organisms on concrete surfaces or plasterboard inside the medical units for long time.