Desenvolvimento de um dispositivo de dispersão de nanopartículas de prata sobre pó polimérico para produção de filme plástico

Abstract

The extrusion process as a mean of film production is not sufficient to guarantee the homogeneous dispersion of the nanoparticles, which compromises the desired antimicrobial action for films used in food packaging. Thus, this work aimed to construct a device capable of homogeneously dispersing silver nanoparticles on polymeric powder for the production of films. The construction of the device looked for the maximum amount of commercial components, in order to keep the cost and the complexity of the project low. Tests of the device were carried out in order to define the best design, aiming at the highest deposition efficiency, after the different configurations, the model used was adopted, which showed an efficiency close to 70%. Five concentrations of silver nanoparticles were prepared, and after the solution was deposited on the powdered polymer, drying was performed and then polymer films were obtained by hot pressing at 160°C for 5 minutes. The films were evaluated by scanning electron microscopy (SEM), optical microscopy and spectroscopy by techiniques of X ray fluorescence, ultraviolet-visible and infrared. SEM analysis allowed to identify the presence of nanoparticles in the polymer powder, the other characterization tests did not detect silver in the film. In addition to these analyzes, the polymeric film was characterized in terms of weight and mechanical strength in the tensile test, in which no changes in physical properties were found. The device was able to impregnate the polymer powder with nanoparticles, so at the end of the project it was concluded that an adapted version of the device could be used in a step prior to a conventional extrusion machine to obtain nanotechnological films with high added value.