Preparation of nanocomposites of PVDF/AuCl₃: formation of gold nanoparticles

Full text: The poly(vinylidene fluoride) (PVDF) is admittedly a ferroelectric material. When polarized at high voltage, exhibit piezo and pyroelectric properties, and can be widely used as a transducer, actuator and sensor for different applications. In recent years there has been a growing scientific interest in metallic nanoparticles, mainly gold (Au) and silver (Ag), due to changes in the physical properties of these nanomaterials. This interest is due to the numerous applications of metallic nanoparticles as sensors, microelectronics, catalysis, bactericidal action and photovoltaic cells. Gold nanoparticles have intriguing optical, electronic, magnetic and catalytic properties. Therefore, the preparation and evaluation of the optical property of PVDF/AuCl₃ nanocomposite aims to develop optical sensors. Films were prepared by mixing an aqueous solution of AuCl₃ 2% PVDF dissolved in dimethylacetamide, sonicated at 60°C for 30 minutes. The solution was poured into a petri plate and dried in a stove at 100°C for 6 hours. A pure PVDF film was also obtained under the same conditions, as a reference. The coloring of the PVDF/AuCl₃ film became reddish along the days. The samples were submitted to X-ray diffraction, differential scanning calorimetry and UV-Vis spectroscopy analysis. The X-ray diffraction results show that PVDF has α phase characteristic, and together with the DSC analysis indicate that the films exhibit the components in their specific structures. The UV-Vis spectroscopy shows an absorption band at 520 nm, characteristic of gold nanoparticles, indicative of the gold reduction to Au⁺³, plasmon band [1]. Reference: [1] Toma, H. et al. Quim. Nova. 2005, V. 28, 5, 897-900.(author)