RESUMO
We prepared nanocomposite inks of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) filled with single-walled carbon nanotubes (SWNTs) purified by acidic treatment, carboxylated by chemical oxidation and carboxyl-functionalized nanotubes physically modified with a natural gum, gum arabic. Inkjet printing of line patterns with a feature size of 100 microm width and lengths ranging from 1 to 5 cm was performed on glass substrates with a piezoelectric inkjet printer. The carboxyl-functionalized SWNT-based composite demonstrated a significant decrease (fourfold) of electrical resistance for the line patterns compared to that with a purified CNT-based composite due to improved dispersability of nanotubes in the polymer matrix. The use of gum arabic for the dispersion of carboxyl-functionalized nanotubes demonstrated a further drastic decrease (18-fold) of the resistance compared with a purified CNT-based composite owing to the formation of an extended continuous network within the line pattern. The inkjet-printed conductive patterns can be applied in various fields, such as flexible high speed transistors, high efficiency solar cells and transparent electrodes.
RESUMO
Gold (Au) nanoflowers have been fabricated using anodic aluminum oxide (AAO) templates assisted electrochemical deposition on the Au film, in which the templates were coated by poly (dimethyl siloxane) (PDMS). PDMS is a viscous, soft material which helps the AAO template to stick to the Au film and assists in the formation of flower-like nanostructures. First, Au nanoplates grew in one-dimensional (1D) pores of the AAO template and uniformly distributed on the Au film; afterwards, the nanoplates continued to grow three-dimensionally because the contracted PDMS provided more space and further formed flower-like shape. The Au nanostructures were characterized by field emission scanning electron microscopy (FE-SEM) as well as energy-dispersive spectroscopy (EDS). Enhanced fluorescence was observably detected along the change of the surface morphology and the nanoflowers exhibited a higher intensity than other Au nanostructures.