Produção e caracterização das nanopartículas poliméricas fotogeradoras de carga

Abstract

Studies in nanoscience have opened doors to several technological developments in different areas. Studies show that one of its applications can produce photovoltaic devices in solar cells for technological purposes, and another presents organic polymers that interact with living organisms, as is the case of the development of an artificial retina. Solar cells, in turn, work through semiconductor photovoltaic (PV) structures that, when absorbing sunlight, are capable of transforming the sun's radiant energy into electrical energy, generating current. The application of organic semiconductor polymers in a similar function to the semiconductor of a solar cell has been very promising. On the other hand, in nanoscience studies, the optical and electrical characteristics of polymeric nanoparticles (NPs) stand out in the development of solar cells, ensuring good absorption of visible light (between 400 nm and 700 nm) and good transport of electrical charge. The present work endeavored to observe how charge photogenerating organic polymeric nanoparticles (NPs) behave when the sonication time used in the miniemulsion is varied. The polymer poly(3-hexylthiophene) (P3HT) is an organic semiconductor widely applied in devices and was used in this work as part of the experiment in the synthesis of NPs by the miniemulsion method, where sodium dodecyl sulfate (SDS) was used as surfactant to stabilize them. The size and absorption characterizations of the P3HT NPs were carried out using UltravioletVisible Absorption Spectroscopy (UV-Vis) and Dynamic Light Scattering (DLS) techniques. The results obtained are very satisfactory: P3HT NPs were found with sizes smaller than 100 nm and with a low concentration of surfactant, an indication of stabilization of the NPs when exposed to visible light, and an inversely proportional relationship between the sonication time used in the miniemulsion method, and the size of the NPs.