Synthesis Core-shell Iron Nanocomposites And Research In Composite Materials

In this paper, we are studied how to synthesised nano-iron particles whichhad a good chemical stability at room temperature and atmospheric pressure,had been applied in composite. Changed reaction conditions to controll themicromorphology, and to find the conditions which can impact themacroscopic properties of the nanoparticles, then, prepared iron nanoparticlesthat have better performance. Secondly, preparaed composite materials whichused polymer coated nanoscale iron particles and resin matrix, and studiedmicromorphology and properties of composites. In addition, researched andanalysised the interface between polymer and metal to know coating principleof coated nano-iron particles. In all researchs, we mainly discussed andanalyzed micromorphology, thermal properties, electronmagnetic propertiesand state of elements in the materials.The micromorphology of coated-iron nanoparticles had been analyzed byTEM, HR-TEM, FT-IR, XPS, XRD, a series of coated nano-iron particleswere successfully synthesized through the characteristic, coexisted ofamorphous and crystalline, particle strings and loops were observed, and the chain structure was not only formed by simple magnetic attraction, butchemical bond. Morphology and particle size of the coated particles weredifferent because of different mechanism, the size of particles about20nm~30nm and shell thickness is about3nm for the PMFe and4nm for thePDMFe, the content of PMMA of PDMFe approximate at31%and26%ofPMFe. Core-shell nanoscale iron particles were paramagnetic materialsbetween the soft magnetic materials and superparamagnetic materials. Theelectromagnetic test showed that their loss mechnism mainly included thedielectric loss of organic "shell" layer, and the magnetic loss through thenatural resonance of nano-Fe "core".The micro-structure of composite materials were analyzed by SEM, XPSshowed that disperstiveness of three kinds of nanoparticles in resin matrixdepending on the particle size. The greater the particle size, the betterdispersion of the particles, and the dispersion order was PDMFe <PMFe<PEG-Fe. In addition, coated nano-iron particles by PMMA have a goodcompatibility in the resin matrix, the content of iron element on compositesurface less than1%. Thermal properties by DSC, TGA and DMTA showedthat adding different nanoscale iron particles which had little effected on thethermal properties of the composite materials, but can increase the glasstransition temperature and modulus of the curing system. Including same ironcontent, Tg of composite which included PMFe larger than included PDMFe. Dielectric properties of the composites by LCR showed that the dielectric loss,and energy consumption, the composite material containing PMFe were betterthan containing PDMFe.