Applied Mechanics and Materials Vols. 448-453

Abstract: s: A novel Schiff-base compound based on ferrocene I has been synthesized and characterized by X-ray diffraction. Electrochemical measurements exhibit that this new ferrocenyl schiffbase undergoes a reversible one-electron redox process.

Abstract: SO₄^2-/ Al-Fe-activated solid acid catalyst has been prepared using cross-linking method, and characterized by FTIR spectra, TG-DTA, XRD analysis. The catalyst is able to effectively catalyse the hydration of turpentine to α-terpineol, with the conversion up to 40% after > 4 uses.

Abstract: The fine cathode material of LiFePO₄/MWCNTs composite was synthesized by ball milling. XRD demonstrated that the particle size of material was smaller when it was milled more time. And SEM showed that the MWCNTs was decentralized into the grains of LiFePO₄. The electrochemical performance of the composite electrodes milled 12h exhibited best electrochemical performance. The electroconductibility of this composite was larger than the others. The specific capacity of it was 132.8mAh/g. So appropriate milling can promote the performance of LiFePO₄/MWCNTs composite.

Abstract: Graphene oxide (GO)/polyaniline (PANI) composite are synthesized via in situ polymerization in the presence of grapheme oxide under acid conditions. The GO/PANI was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM) and electrochemical testing. The cathodes prepared using PANI and GO/PANI delivered initial discharge capacities of 78mAh/g and 104.4mAh/g ,respectively stable reversible capacities of 58.5mAh/g and 103.7mAh/g after 50 chargedischarge cycles. The GO enhances the discharge capacity of the PANI electrode material. GO/PANI is a good candidate as electrode material in lithium ion batteries

Abstract: Positive materials for nickel/metal hydride battery, nickel hydroxide doped by different metal ions were synthesized by coprecipitation, and subsequent hydrothermal treatment and anion exchange method. The structure of the samples was analyzed by XRD test, and the electrochemical performances were studied by galvanostatic charge-discharge, cyclic voltammetry and impedance tests. The obtained electrode material shows mainly β-Ni (OH)₂ structure when only doping Zn²⁺, while α-Ni (OH)₂ structure was obtained by only doping Al³⁺ or co-doping Al³⁺ and Zn²⁺. Ni (OH)₂ co-doped Al³⁺ and Zn²⁺ had fine cyclic stability, high number of exchanged electrons per nickel atom (the maximum is 1.93), small charge-transfer and proton-diffusion resistances.

Abstract: Photocatalytic hydrogen production from water splitting with semiconductor materials has received intense attention due to its potential to address important energy and environmental problems. In this work, we reported the facile preparation of NaInS₂ photocatalyst with hierarchical nanostructure using solvothermal method. The as-prepared NaInS₂ photocatalyst was extensively characterized with X-ray powder diffraction, UV-Vis spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. It was found that the as-prepared NaInS₂ was composed of numerous interconnected nanoplates with thickness of around 100 nm. Reaction parameters such as the synthesis temperature and duration were found to be crucial for the formation of crystalline NaInS₂. Moreover, ethylene glycol played an important role in tuning NaInS₂ with hierarchical nanostructure. The as-prepared hierarchical NaInS₂ photocatalyst demonstrated strong absorption in the visible region and appreciable activity for the photocatalytic H₂ production from water splitting under visible light irradiation (λ > 420 nm).

Abstract: (Pr_0.5Nd_0.5)_0.7Ca_0.3Cr_1-xCu_xO_3–δ(PNCCCx x=0, 0.5, 0.1, 0.15，0.2 ) interconnect material and electrolyte powders of Sm_0.2Ce_0.8O_1.9 (SDC) were synthesized by citric acid nitrates self-propagating combustion methodThe phase and microstructure of the sintering samples were investigated by X-ray diffraction and scanning electron microscope, respectively. The electrical conductivity of the samples were measured by four-probe technique. The results indicated that there is no new-phase were detected after co-firing between Cu-doping PNCC and SDC at 1350°C for 5 h. In air or H₂ atmosphere, the conductivity of the sintering ceramics increasing with temperature, as well as the Cu-doped contents. At 800°C, the conductivity for PNCCC0.05 reached 37.54S/cm in air, and the maximum of PNCCC/SDC reached 44.52 S/cm in air 30.68 S/cm in H₂, respectively. The average thermal expansion coefficient of the series ceramics is between10.4×10^-6 K^-1 to 10.8×10^-6K^-1 at the RT-1000°C, which is close to that of the SDC electrolyte. Our results indicate that the PNCCC compounds is a very promising interconnect material for intermediate solid oxide fuel cells.

Abstract: Sulfonated endcapped poly (arylenethioethersulfone) copolymer (SPTES) was synthesized through direct copolymerization of sulfonated monomers and poly (vinyl alcohol) (PVA) was crosslinked with SPTES by the dehydration method. The mechanical characteristics of polymer actuators are investigated. Nafion actuators as a comparison were also investigated. The normalized tip displacements were calculated for both PVA/SPTES actuators and Nafion actuators in order to delete the dimensions influence on the bending behaviours. The bending performances were tested under AC excitations with different frequencies. The results showed that the normalized tip displacement decreased with both the width and length of the IPMC strips. That is due to the increase of the monment inetia of the IPMC strips with the increment of the width or the length increment will lead to the larger resistance force from ambient water along with the increase of the area of IPMC strips. PVA/SPTES actuators showed comparable bending performances compared with its Nafion counterparts based on the study of mechanical properties.

Abstract: The preparation of highly dispersive silver particles of average particle size of 1~2μm used for the front paste of the solar cell were carried out by rapid addition of ascorbic acid solution into the aqueous AgNO₃ solution at room temperature. The dispersive quasi-spherical silver particles were obtained with the AgNO₃ concentration of 0.1M, AgNO₃/Ascorbic acid mass ratio of 1:0.8 without controlling the pH value of the system. Elevating the concentrations of the AgNO₃ solution resulted in the formation of flowerlike structures. The formation mechanism was investigated, it was concluded that the growth process of the highly dispersive silver particles include three stages, first, the formation of the precursor, followed by the nuclei burst and the diffusive growth process due to formation of H⁺ ions adsorbed on the negative charged Ag nuclei as well as the steric effect of the ascorbic acid molecule, finally, when the pH value decreased dramatically to approaching the isoelectric point, the adsorbed H⁺ was released and the resulting primary particles in turn aggregated to form secondary particles.

Abstract: Polyoxymethylene dimethyl ethers (DMM_n) were synthesized in moderate yields by the reaction of methylal and paraformaldehyde catalyzed by solid acid. The pure components of DMM₂, DMM₃, DMM₄, and DMM₅ obtained by rectification were characterized by ¹H NMR and mass spectra. The suitable components for blending into fuel were obtained by distillation separation. Furthermore, the combustion and emission characteristics of a diesel engine fueled with diesel and a blended fuel of DMM_3-5 and diesel were investigated respectively.