Electrical and Optical Properties of Conductive and Transparent ITO@PMMA Nanocomposites

In this work, nanocomposite films of indium tin oxide (ITO) nanowires in a PMMA matrix were obtained by tape casting. The electrical, optical and morphological properties of films were studied as a function of the amount of wires inserted in the composite, and it was used 1, 2, 5, and 10 wt %. Results confirmed that films transmittance decreases as the concentration of wires increases, attaining a minimum transmittance of 55% for 10 wt % of filler. on the other hand, the electrical resistance of composites was found to decrease by increasing the filler amount and the dc characterization indicate that percolation occurs for about 5 wt % of wires. The morphological studies carried out by TEM were considered to be in good agreement with the electrical results and confirm that for 5% of filler, the ITO nanostructures are in contact with one another inside the polymer. Moreover, we made computational simulation of ID structures in a general matrix and it was found that percolation should occur for about 12 wt %. Although computational results indicate higher amount of wires necessary for percolation than we found experimentally, both results illustrate that using one-dimensional nanostructures as filler in composites enables obtaining percolation for a smaller amount of filler than when using, for instance, nanoparticles. Therefore, the simple processing technique employed here can be used to obtain transparent and conductive composites with several useful applications.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq