Preparation And Properties Study On K-PBA And Na-PBA Magnet Nanomaterials

In recent years, the preparation and application of cobalt-iron Prussian blue analogues containing alkali ions have been the hot in the studies of materials, but unfortunately, the preparation and magnetic study on their nanomaterials are rather scarce. To prepare nanomaterials in microemulsion is a valuable new way because the size and morphology of products can be controlled artificially. Herein, the dissertation gives emphasis to the synthesis of Prussian blue analogues containing sodium and potassium ion in microemulsion. The products were characterized by TEM,SEM,EDS,XRD,IR,UV-Vis and SQUID etc. The results are shown in the following four sections:1. Mixed cubic and rod nanoparticles of cobalt-iron Prussian blue analogue containing potassium ions, about 50 nm, were synthesized in cetanyl trimethyl ammonium bromide (CTAB)/pentanol/isooctane/water, and products with different potassium content and cobalt-iron ratio had been successfully synthesized by changing the reactant concentrations at 10℃. To the best of our knowledge the synthesis of rod cobalt-iron PBA nanocrystals have not been reported previously. TEM and SEM were employed to examine the morphology and dimension of the cobalt-iron PBA nanoparticles. TGA,ICP,EDS and CHN analysis were used to determine the element composing, and it was deduced that the products were complexed with CTAB. Furthermore, XRD,IR,SQUID were exploited to characterize the generation of magnetic properties. The results show that the magnetic propertites of the products are intensively dependent on the potassium contents and cobalt-to-iron ratios, and have little relation to their morphologies. Additionally, it is found that the products which complexed with CTAB exhibit higher Curie temperature.2. 30 nm spherical, 60 nm cubic and 30 nm hollow cubic nanoparticles of cobalt-iron Prussian blue analogues which contain potassium ions were synthesized in polyoxyethylene tertoctylphenyl ether (Triton X-100)/ n-hexanol/ cyclohexane/ water reverse microemulsion system. The effects of w and different concentration ratios of reactants on the morphology of products were studied, SQUID were exploited to characterize the generation of magnetic properties. The magnetic study indicates that the magnetic propertites of the products are intensively dependent on the potassium contents and cobalt-to-iron ratios, and have little relation to their morphologies. Additionally, three products, including hollow cubic nanoparticles, have superparamagnetic properties, and there is no report about the magnetic properties of hollow cubic nanoparticles previously.3, 5 nm spherical and 80 nm cubic nanoparticles of cobalt-iron Prussian blue analogues containing potassium and sodium ions were synthesized in microemulsion which containing surfactant sodium bis(2-ethlhexyl) sulfosuccinate(AOT)/ isooctane/ water. The effects of w, the concentration of reactants and the reaction temperature on the morphology of products were studied. The products were characterized by XRD,TEM,EDS and UV-vis.4. Cobalt-iron Prussian blue analogues which contain sodium ions were synthesized by using aqueous method, microemulsion method, hydrothermal method, microemulsion-hydrothermal method. The effect of different method on the content of sodium and cobalt to iron ratio were studied, and the products were characterized by SEM and EDS. The results show that smaller amount of sodium ions could enter in the crystallize only when we use Na₃Fe(CN)₆·10H₂O as the reactant.