Advanced Materials Research Vols. 557-559

Abstract: Two-layered Cu-Ni-Zn/Cu-Cr clad material was prepared by high temperature diffusion bonding and their mechanical performances were examined. Tensile testing was performed on Cu-Ni-Zn/Cu-Cr with the interface plane perpendicular to the stress axis. No intermetallic compounds were observed at Cu-Cr/Cu-Ni-Zn interfaces. In the deformed as-bonded specimen, plastic deformation took place mostly in the softer Cu-Cr alloy although some slip traces and surface irregularity due to grain distortion are discernable in Cu-Ni-Zn alloy. In the deformed heat-treated Cu-Ni-Zn/Cu-Cr, the strength of Cu-Cr increased significantly and plastic deformation occurred mainly in Cu-Ni-Zn with some indication of slight deformation in Cu-Cr close to the interface. Fracture occurred in the necked region of the softer material. The excellent mechanical reliability and the good interfacial bonding strength can be attributed to the absence of detrimental interfacial reaction compounds between Cu-Ni-Zn and Cu-Cr.

Abstract: Mesoporous silica microspheres (MSM) with diameter about 100 nm were prepared by hydrothermal synthesis using cetyl trimethyl ammonium bromide(CTAB) as template agent and tetraethyl orthosilicate(TEOS) as silica source. And they were characterized byscanning electron microscopy (SEM) , N2 adsorption-desorption analysis , infrared spectroscopy (FT-IR). Then methylene blue adsorption test was investigated. Effect of pH, temperature of the adsorption of methylene blue onto MSM were studied. The adsorption amount onto MSM increased with the initial pH-value of the solution in the range of 3~10. Alkaline was more favorable to adsorption. The adsorption amount onto MSM decreased with the initial temperature of the solution at 22 °C~ 45 °C. low-temperature was more favorable to adsorption. The adsorption isotherm of methylene blue on MSM could be described by the Langmuir model.

Abstract: FA-targeted and 10-hydroxycamptothecin loaded chitosan nanoparticles (FA-HCPT-NPs) were prepared with a combination of emulsion-solvent evaporation and chemical crosslink method. The analysis revealed that the FA-HCPT-NPs were spherical with diameter of 255.5  16.2 nm, zeta potential of + 70 mV, HCPT encapsulation efficiency of 81.2% and loading rate of 2.5%. X-ray powder diffraction illustrated that HCPT was buried as an amorphous form in the NPs. The release profiles of HCPT exhibited a biphasic pattern characterized by an initial burst release followed by a slower and sustained release. The results indicated that the novel FA-HCPT-NPs could be a potential drug delivery system for tumor cell-selective targeting therapy.

Abstract: Mono-dispersed Nickel oxide nanoparticles were directly formed on the carbon fibers through a facile in situ flame synthesis method. High magnification SEM and TEM study revealed that the nickel oxide nanoparticles have a polyhedral structure and are uniformly distributed on the surface of carbon fibers. The concentration effect of the precursor used on the growth of polyhedral nickel oxide nanoparticles on carbon fibers has been studied.

Abstract: The synthesis of intermetallic Ni-Al nanoparticles by co-reduction approach of several organometallic precursors with sodium naphthelide in non-aqueous solution was studied. The state of the art in nanoparticles synthesisation is the selection of suitable precursors and the adaption of colloid chemistry to non-aqueous media at the room temperature under inert atmosphere. The reduction of an organometallic precursor, nickel (II) acetylacetonate, Ni(Acac)₂ as a source of Ni element of the intermetallic, and aluminum trichloride, AlCl₃ in tetrahydrofuran (THF) solution gave a black particles. The powder X-ray diffraction spectroscopy (pXRD) result shows an expansion of lattice parameter for FCC-Ni indicating the cooperation of Al atoms in Ni structures. The estimation value of Al concentration using Scherrer’s equation is 10 at%. The particles were investigated in more detail by hard X-ray photoemission spectroscopy (HX-PES). The HX-PES spectrums confirmed that the black particles has binding energy consistent to standard materials of Ni₃Al. The absence of organic residues shown by the Fourier-transform infrared, FTIR spectrometer indicates that the as prepared Ni-Al nanoparticles are free from by-products.

Abstract: A DFT study of the catalytic properties of CuO/CNT and CuO@CNT complexes for the heterogeneous catalytic ozonation has been performed. We illustrated the atomistic details of CuO/CNT and CuO@CNT with a quantitative and qualitative discussion within such an electronic structure characteristics. Ozone was catalytically decomposed into an atomic oxygen species and oxygen molecule on both the surface inner and outer CuO@CNT complex, while ozone can only decompose over CuO on the outer surface of CuO/CNT, with partial electrons transfer from CuO/CNT and CuO@CNT complexes to the adsorbate. Then the atomic oxygen reacted with the water molecule to form two hydroxyl groups on the surface, promoting the reaction chain for the generation of•OH which, in turn, lead to an increase in the catalytic ozonation efficiency. Results show synergetic confinement effect of metal oxide nanoparticles inside CNT could also lead to an acceleration of ozone decomposition and the generation of •OH on the inner and outer surface of carbon-nanotube containing catalytic particles.

Abstract: In this paper, the chlorinated poly (vinyl-chloride) (CPVC) nanofiber were successfully prepared via electrospinning of the proper spinning solution, which was obtained by dissolving CPVC granules in N,N-dimethylformamide (DMF) and tetrahydrofuran (THF) mixture. The results indicates that the morphology of the fibers is influenced by solution concentration and applied voltage. The finer and uniform nanofiber is electrospun from total solid content of the spinning solutions at 16wt.% and the spinning voltage at 26kV. The surface potential of CPVC nanofiber nonwovens increases with the spinning voltage and the filtration efficiency increases firstly and then decreases. In spinning voltage of 26 kV, filtration efficiency reaches a maximum of 99.925%.

Abstract: Alumina fiber, a kind of inorganic fiber, was widely used in many fields owing to its excellent performance. CeCl₃/AlCl₃/PVP was used as spinning solution for producing organic-inorganic hybrid fiber by electrospinning, then, alumina fiber doped cerium can be successfully obtained after high temperature calcination. In the paper, the influence of CeCl₃ to the crystallization and thermal stability was discussed. The results show that alumina nanofiber with average diameters of 200nm-800nm are obtained by calcination of the as-prepared fibers .The addition of CeCl₃ significantly delay the crystallization transformation process of alumina fiber, while the formation of CeO₂ reduce diffusion rate of Al3+, eventually, imped the phase transformation of Al₂O₃ and improve its thermal stability.

Abstract: As an emerging discipline, nanotechnology not only has been applied and popularized rapidly, but also widely used in sports equipments. In order to discuss the application of nanometer materials into the badminton equipments, this study introduces the development of nanotechnology and the manufacturing process of the nanofiber, analyzes the limitations and deficiencies of the traditional badminton racquet strings, and compares the racquet strings which are made from nanofiber with traditional racquet strings; the result shows that the badminton racquet strings which are made from nanofiber have prominent mechanical property and operational performance in comparison with the traditional racquet strings, and have very great application prospects. The application of the badminton racquet strings which are made by nanofiber materials is an inevitable trend.

Abstract: In the current research, ZnO nanoparticles have been synthesized via sol-gel technique assisted by a pre-hydrothermal treatment at 150oC with various holding time of 0, 24, 48 and 72 hours. This route was specifically aimed at investigating the effect of this treatment on the nanocrystallite size, crystallinity and band gap energy of the resulting nanoparticles. The results of investigation showed that an increasing of pre-hydrothermal treatment duration from 0 to 72 hours has increased the crystallite size of ZnO nanoparticles from 3.47 to 13.85 nm, and decreased the band gap energy from 3.10 to 3.08 eV.