Synthesis And Properties Of Nano-silver/pani Composite Materials

Composite materials of conducting polymers and metal particles have received much attention during the last few years. They have shown various interesting properties that can be expected to be different from those of the polymers or the metal particles themselves. They have potential applications in electrocatalysis, chemical sensors, electrochemical capacitors and protective coatings against corrosion. Among conductive polymers, polyaniline (PANI) has attracted considerable interests due to its availability, simple synthesis, high conductivity and stability. Nano-silver particles have been applied in ceramics, coatings and environmental protection because of its excellent physico-chemical properties.The composite material of silver and polyaniline was synthesized by two-step technology. Some parameters, such as reaction time, temperature, concentration of silver nitrate, polyaniline's mass and assistant reducer, were varied to obtain optimum conditions, which was as follows:reation time was 36 h, temperature was 40℃, concentration of silver nitrate was 0.4mol/L, and mass of polyaniline was 1g. The nitric acid was also used to synthesize composite material by one-step technology, the effect of temperatures on the conversion percent was also explored.Transmission electron microscope, X-ray diffraction, resistivity measuring instrument with Four-probe, electrochemistry workstation, UV-vis spectrophotometer and FT-IR spectrum were used to characterize these composite materials. The results showed that silver nanoparticles about 30nm were dispersed in polyaniline matrix. At similar conditions, the conversion percent of silver nitrate in one-step technology was much higher than that in two-step technology.