Characterization Of In Situ Synthesis And Properties Of Nano Ni / Pani

The nano-nickel powder is one of the most important magnetic metal materials applied widely in catalysis, magnetic materials, conductive materials and shielding materials due to their special physical properties. Therefore, the nano-Ni/PANI composites with both conducting and ferromagnetic properties have the important prospect in the field of electromagnetorheological shield and chemical catalysts. In this research, the nickel (Ni) nanoparticles were prepared with 1, 2-propanediol as the reductant. The synthetic condition, particle size-controlled and surface modification of the Ni nanoparticles were systematically investigated. Based on these studies, nano-Ni/PANI composites were prepared by in-situ synthesis and Pickering Emulsion polymerization, and the relations between their structures and properties were discussed.Ni nanoparticles with different morphologies, such as sphere, thorn-sphere and snowflake shape, were prepared by using nickel acetate as precursor, 1, 2-propanediol as solvent and reductant, with different surfactants as modifiers. These modifiers are laurylamine, polyvinyl pyrrolidone (PVP) and oleic acid, respectively. The effect of the concentration of modifier and NaOH on morphology and size of Ni nanoparticles were discussed. The systhesis mechanisms of Ni nanoparticles with different morphologies were investigated. SEM showed that different surfactants were important for preventing the Ni nanoparticles from agglomeration and uniformity of nanoparticles, the minimal size of Ni nanoparticles prepared was less than 50 nm and the concentration of NaOH strongly influenced on the size and the degree of agglomeration. The certain interaction between the modifiers and Ni nanoparticles was proved by FTIR. Ni nanoparticles modified by oleic acid responded for the good stability and acid resistance.Nano-Ni/PANI composites were prepared by a novel solids-stabilized emulsion (Pickering Emulsion) route for the first time. The sphere-like and nano-rod morphology of nano-Ni/PANI composites were synthesized in a toluene/water emulsion stabilized by oleic acid-stabilized Ni nanoparticles. SEM showed that morphology of the resulting Ni/PANI nanocomposites depended on the amount of Ni in the reaction system. The strong interaction between Ni nanoparticles and PANI was proved by FTIR and Raman. At the same time, their electrical properties of the nano-Ni/PANI composites were also affected by the content of Ni. The conductivities of nanocomposites reached the maximum value, 2.7 S/cm with 2 wt% Ni loading.The nano-Ni/PANI composites with the Ni content up to 20 wt% can be obtained by liquid phase reduction method in the presence of PANI. SEM images of nano-Ni/PANI composites showed that Ni nanoparticles were inlaid homogeneously in the surface of PANI. Ni nanoparticles were the typical diffraction patterns of single-phased and face-centered cubic (fcc) phase in the surface of nanocomposites, and the certain interaction between Ni nanoparticles and PANI was proved by FTIR and Raman.