Advanced Materials Research Vol. 815

Abstract: Self-assembly of symmetric diblock copolymers (DCP) confined in multiwalled carbon nanotubes (MWCNTs) is studied using coarse-grained molecular dynamic (MD) simulations. The dependence of the self-assembled morphologies on the strength of the surface interactions is examined systematically. A rich variety of novel morphologies under the three-dimensional confinement have been revealed. The adsorption energy and cohesive energy have been discussed qualitatively and used to account for the appearance of the complex morphological transition.

Abstract: In this paper, the higher-order elasticity constants are evaluated in the theoretical scheme of higher-order continuum. A single-walled carbon nanotube is treated as a higher-order continuum cylindrical tube with a thin wall, and the representative cell is chosen as a triangle unit that contains four carbon atoms. The Brenner potential is employed to describe the C-C atomic interaction, and the higher-order constitutive relationship is derived by virtue of the higher-order Cauchy-Born rule. The higher-order elasticity constants of carbon nanotubes are evaluated based on the derived higher-order constitutive model, which can provide a foundation for the further analysis of the mechanical properties of carbon nanotubes in the theoretical scheme of higher-order continuum.

Abstract: In this paper, Ce⁴⁺ and Fe³⁺co-doped titanium dioxide nanocomposite was prepared by iron nitrate, cerium sulfate and titanium sulfate as raw materials and sodium dodecyl sulfate as surfactant under microwave irradiation. The x-ray diffraction (XRD) results show that as-prepared sample of direct adding doped cerium and iron content were 0.2% and 0.5% of titanium sulfate amount of substance calcined at 500°C for 2 h is anatase. We also studied the photocatalytic activity of the as-prepared Fe³⁺ and Ce⁴⁺ co-doped TiO₂ nanocomposite by using degradation of methyl orange solution. The effect conditions of photo-catalytic activities of the composite were investigated, such as different ratios of direct adding doped iron and cerium content, different dosage of hydrogen peroxide, different pH value, and different dosage of nanocomposite. When the catalyst is 1.0 g/L, pH value is 4.3, C(H₂O₂) is 3 mL/L, the effect of the visible light catalytic activity was the best, in 20 min, the degradation rate of 20 mg/L methyl orange solution was more than 90%. Obviously, as-prepared Fe³⁺ and Ce⁴⁺ co-doped titanium dioxide nanocomposite as photocatalysts for degradation methyl orange, has a significant effect. Moreover, the operation was simple, and there was no secondary pollution. In a word, it has a good prospect.

Abstract: In China, the application of condensing lining in submerged arc furnace for producing high-carbon ferromanganese started with the introduction of Ucar technology from USA through Shanxi Yi Wang Ferroalloy Co. Ltd. At present, the technology and service can be also provided by Henan Fang Yuan Group. However, it is still applied in submerged arc furnace for producing high-carbon ferromanganese. The application of condensing lining in large-scale submerged arc furnace for producing ferronickel is still in the exploration stage. In this article, based on communicating with technician worked in ferronickel corporation, enterprises devoted effort to the research & development of condensing lining and summarizing nickel iron production experiences, referenced advices for structure and design of condensing lining were put forward.

Abstract: Eu²⁺-doped Ba₃La (PO₄)₃ phosphors were synthesized by solid-state reaction method. The X-ray diffraction (XRD) results showed that the obtained phosphors were cubic phase. The structure of Ba₃La (PO₄)₃ doped slight Eu²⁺ does not changed. Ba₃La_1-x(PO₄)₃:xEu²⁺ phosphor can be excited by UV-visible light, which emits intensely blue light with broadband peaked at about 466 nm. The relative PL intensity increases with Eu²⁺-concentration increasing until a maximum intensity is reached, at about x=0.015mol. According to the Dexters theory, it was found that the major mechanism for concentration quenching as a result of dipole-dipole (d-d) interaction.

Abstract: Bone-like fluoridated hydroxyapatite (FHA) coatings were prepared on Ti-6Al-4V substrates (TC4) by using laser cladding. This bioceramic coating was fabricated by adding CaF2 micron-particles into the hydroxyapatite before presetted on the Ti alloy substrate and radiated by laser beam which aimed at obtaining lower solubility, fine thermostability and maintaining the comparable bioactivity and biocompatibility. Coatings, which were processed using a Nd:YAG laser cladding, presented FHA crystallization on the surface with a uniform morphology along the coating cross-section and no significant dilution of the titanium alloy was observed. Phase analysis by X-ray diffraction indicated the generation of fluoridated hydroxyapatite phase in the laser cladded coatings. The coatings showed the formation of a metallurgically sound and diffused substrate-coating interface, which significantly increased bonding strength between the coatings and subtrate. The bioactive coatings afforded favourable bone bioactivity by inducing the rapid precipitation of apatite on their surface when immersed in a simulated body fluid (SBF). The work demonstrated the potential of using laser cladding for fabricating fluoridated hydroxyapatite bioceramic coatings on Ti alloy.

Abstract: With chemical modification method, the epoxy resin E₄₄ was modified into water-borne epoxy resin by diethanolamine, considering the compatibility of curing agent and resin, diethylenetriamine was modified into epoxy amine curing agent as well, through single factor method to discuss the effects of reactant ratio, reaction temperature on the results of the product, the structure of the product was analyzed by Infrared spectrum. The experimental results showed that, when molar ratio of epoxy resin and diethanolamine was 4:3, reaction temperature of 70-80°C, the preparation of waterborne epoxy resin emulsion has small particle size and good stability. At the same time, when molar ratio of epoxy resin and diethylenetriamine was 1:1, reaction temperature of 80°C, the performance of waterborne epoxy curing agent is well.

Abstract: Thermoplastic polyurethane (TPU) has been used to toughen Poly (3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB) and increase its cold-resistance. The compatibility of P34HB/TPU blends was predicted by solubility parameter, then investigated by appearance and transparence, Dynamic Mechanical Analysis (DMA) and Scanning Electron Microscopy (SEM) analysis. The P34HB/TPU was found to be a partly compatible system. The appearance and transparence of P34HB/TPU blends were smooth and non-transparent. The DMA showed that the glass transition temperature of P34HB was decreased with the increase of TPU content. The SEM photos showed that the morphology of the P34HB/TPU blends were the sea island structure.

Abstract: For understanding the dynamic behavior of watery cellular foam subject to a shock wave, this paper through experiments, to gain a deeper understanding of the incidence, reflection and transmission of a shock wave when it interacted with watery foam. Moreover, by analyzing the loss of the peak overpressure and positive impulse, we were able to respectively know the positive impulse of the incidence, reflection and transmission shock wave. The experimental results indicated that the attenuation capability for watery foam to the shock wave was caused by the internal friction and the water atomization, which would absorb the energy of the shock wave. Therein, the higher percentage of water in the cellular foam, the more obvious attenuation phenomenon for the shock wave was presented. However, the mechanical processes of cellular foam with different water percentages subject to the shock wave were not completely consistent.

Abstract: A novel and highly efficient photocatalyst, Eosin Y-sensitized Pt-intercalated nanotube Pt/HLa Nb₂O₇, was found to be very active for hydrogen generation within triethanolamine (TEOA) solution as the electron donor under visible-light irradiation (λ 420 nm). The photocatalysts were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectra (DRS), scan electron microscope (SEM) and energy dispersive spectrometer (EDS). The results showed that the significant enhancement of photocatalytic activity was achieved via Pt intercalating and subsequent dye sensitization of Pt/HLaNb₂O₇. The highest rate for hydrogen evolution was 4.45 mmol·g^-1·h^-1 under irradiation with a wavelength longer than 420 nm, and the probable mechanism of photosensitized hydrogen evolution have also been discussed.