Advanced Materials Research Vols. 557-559

Abstract: Nanocrystalline ceria powder was prepared through homogeneous precipitation method, orthogonal experiment was designed to figure out the most important factor that influence the particle size of the resultant and the optimum condition. X-ray diffraction revealed that the as-prepared nanoscale ceria powder had cubic fluorite structure, TEM image showed that the ceria powder was weakly agglomerated with a particle size of about 10 nm.

Abstract: We reported a facile synthesis route for size controlled preparation of gold nanoparticles (Au NPs) by controlling concentration of the reducing agent and temperature. Nearly monodisperse Au NPs with mean diameters of 2-6 nm are acquired via the reduction of HAuCl₄ by NaBH₄ in the presence of tri-n-octyl amine and dodecanethiol in solvent of toluene. Results indicate that concentration of the reducing agent and temperature are key factors to tune the particle size and uniformity in the synthesis of Au NPs. The as-synthesized Au NPs show size dependent surface plasmonic properties between 510 and 525 nm, while Au NPs with size smaller than 3 nm do not clearly show the property.

Abstract: In this paper, we reported that firewood-like CeO₂ nanostructures were synthesized via hydrothermal method in the present of cetyltrimethylammonium bromide (CTAB) for the first time. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) were used to characterize the as-obtained sample. The UV absorption property of the product was investigated by UV-vis spectrophotometry. XRD result shows that the product was a cubic fluorite-type CeO₂ phase with good crystallinity. FE-SEM and TEM analysis indicate that the firewood-like CeO₂ nanostructures were composed of CeO₂ nanoparticles with the average size of about 6-10 nm. The CeO₂ shows excellent UV absorption for that the transmittance (T %) of the sample in the UV region almost equal to zero.

Abstract: In this paper, a new method for the preparation of composite nanofibers surface containing calcium carbonate nanoparticles using electrospinning technology was described. In detail, firstly, the type solution is formed by the aqueous solution of CaCl₂ which contains polyvinylpyrrolidone (PVP) and the other is the aqueous solution of K₂CO₃. Two types of solution were mixed completely, and then Ca²⁺ and CO₃²⁻ generated CaCO₃ nanoparticles. Secondly, composite nanofibers with CaCO₃ nanoparticles were successfully prepared by above solution electrospun. The resulting composite nanofibers were characterized by field-emission scanning electron microscopy (FE-SEM), it determination showed that perfect mono-dispersed spherical CaCO₃ nanoparticles were dispersed on polyvinylpyrrolidone (PVP) nanofibers.

Abstract: The filling of carbon nanotubes with Fe-Mn oxide via wet chemistry was presented. IR, XRD and TEM were used to characterize the structural features and the morphology. Cyclic voltammetry was used to investigate the electrochemical behavior of the samples. Results shows that the Fe2O3 and MnO2 were filled the tube inner cavity successfully and the nanocomposites were valuable for supercapacitor materials.

Abstract: Oxidized MWNTs were obtained by the oxidization in the mixture of concentrated HNO3 and H2SO4. Amino-functionalized MWNTs were obtained by the oxidized MWNTs reacting with aliphatic amines. The structure and properties of functionalized MWNTs were characterized by FT-IR, TGA, XRD and nanoparticle size analyzer.

Abstract: In the MTS testing machine, Quasi-static tensile mechanical testing is carried on to different Nano rubber epoxy, and have gained its mechanical properties; basing on the testing figures, ZWT constitutive model is used to descript the tensile mechanical properties of materials, and five parameter values are gained under low frequency of the model through numerical fitting; With the comparison of the test data , the numerical fitting result is in good agreement with test, at the same time, it also show that ZWT constitutive model can well descript the Quasi-static tensile mechanical properties of epoxy resin filled by nano-rubber.

Abstract: The morphology and collection rate of Cu-30wt%Ag alloy nano particle prepared by induction plasma system with different power were studied. The results indicate that with the power of plasma increasing from 30 KW to 45 KW and then to 60 KW, the average size of Cu-30wt%Ag nano particle of 89 nm, 72 nm and 50 nm is obtained respectively, and the collection rate improves from 47.5% to 50.1% and 55.2%. Meanwhile, the plasma power has an obvious effect on the specific area of nano particle.

Abstract: A novel nanoenergetic material was prepared by filling KNO₃ in the CNTs through a wet chemical method. The samples were characterized by TEM, XRD, and TG/DSC. The results show that KNO₃ with a mean diameter of ~9 nm were homogeneously filled into CNTs to form KNO₃@CNTs nEMs. The TG/DSC curves indicate that the reaction enthalpy (ΔH) of KNO₃@CNTs nEMs was 876.1 J/g and the characteristic temperature of the exothermic peak was 386.8 °C.

Abstract: In this paper, we employed Methanol, 75% Ethanol, 100%Ethanol, and Isopropanol to treat electrospun SF nanofiber mats, and studied the morphology, structure and property of SF nanofiber before and after treatment by means of SEM, and FTIR. While the as-spun SF nanofiber mats consisted of α-helix and random coil, post-treatment of the SF nanofiber resulted in significant increase in β-sheet component and improvement of water resistance of the SF nanofiber mats. This effect was not obvious affected when different post-treatment system was used, but methanol and 75% was more effective in inducing conformation transition from α-helix and random coil to β-sheet.