Advanced Materials Research Vols. 391-392

Abstract: A novel kind of efficient solid polymer electrolyte (SPE) based on crosslinked polyester matrix has been prepared by employing low molecular weight PEG (oligo-PEG, Mw = 400 g/mol), followed by crosslinking of the PEG with citric acid (CA). The oligo-PEG, with small coil size, can be easily penetrated into mesopores of TiO₂ photoelectrode, while the mechanical stability of the SPE can also be maintained by crosslinking. The factor of weight ratio of CA cross linker in the hybrid plays an important role in determining the intersegmental distance and free volume of the polymer matrix, which sequentially affects the electrochemical activity of the conductive ions and then the ionic conductivity of the polymer electrolyte. By using the 32.4 wt.% CA in the matrix, the SPE with the optimal room temperature conductivity (σ) of 5.43×10^-5 S/cm was obtained.

Abstract: Effect of rotating electromagnetic field on the conductivity of aqueous NaCl solution was investigated by experiments. NaCl solution was circulated at a constant flow rate in the flow loop with a rotating-electromagnetic generating device for a period of time. Then conductivity of NaCl solution was measured at different NaCl solution contractions and rotating electromagnetic fields. Simultaneously, the conductivity was determined for NaCl solution untreated magnetically, as a reference. It was found that the rotating electromagnetic field influenced conductivity of aqueous NaCl solution and made it increased. The mechanism of the effect of the rotating electromagnetic field on conductivity of NaCl solution was also discussed.

Abstract: A series of Co-B alloys with uniform nanoparticles were prepared via a vacuum freeze-drying method, which the precursors of Co-B alloys were prepared by the reduction of bivalent cobalt chloride with aqueous sodium borohydride solution. The alloys were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and brunauer emmett teller (BET) surface area measurement. The electrochemical activities of Co-B samples were examined by charge-discharge test. This work studied the influence of pre-freezing time on the microstructure and electrochemical performance. The sample pre-freezing for 3 hours exhibits the best cycling performance than others, the discharge capacity increase to its maximum 438mAh/g, and it still remained 232 mAh/g after 60 cycles at a current of 50 mAh/g; while those of samples pre-freezing for 1 hour and 5 hours are 399 mAh/g and 413mAh/g, respectively.

Abstract: Composite FeF₃•3H₂O/C was prepared by mixing FeF₃•3H₂O with acetylene black through high-energy milling, and used as cathode material for Li-ion battery. The structure and the morphology of the as-prepared composite FeF₃•3H₂O/C were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). When compared with FeF₃•3H₂O synthesized by a liquid-phase method, the composite FeF₃•3H₂O/C had no distinct difference in crystal structure, but shows that a well distributed particle size of 100~1000nm. The electrochemical performances of FeF₃•3H₂O/C composite were evaluated by charge-discharge test and cyclic voltammetery (CV). With a current density of 23.7mAg^-1 in the voltage range of 2.0~4.5V at room temperature, the FeF₃•3H₂O/C composite achieved a maximum discharge capacity of 112 mAhg^-1, as well as a good cycling performance.

Abstract: NaCl solutions of different concentrations were exposed to alternating and stationary magnetic fields. The conductivity change of the NaCl solutions was measured. The change of the conductivity of the NaCl solutions under different amplitudes magnetic fields was studied. The differences of effect between stationary and alternating magnetic field on the conductivity of the NaCl solutions was compared. The principle of the effects of magnetic fields on conductivity of NaCl solutions was discussed. The process of magnetic moment deflexion effected by the alternating magnetic field was analyzed, which explained the experimental results that the conductivity was increased more larger when then the NaCl solutions were exposing to alternating magnetic field than stationary magnetic field.

Abstract: In this paper, nickel plating graphite nanosheet (Ni plating GN) was developed by electroless plating method using graphite nanosheet (GN). The Ni and P content on the surface of GN is 34.08wt% and 2.99wt% according to the elementary analysis. The electrically conductive adhesives (ECAs) comprised acrylate pressure -sensitive adhesive (acrylate PSA) and Ni plating GN was studied. TEM result showed that Ni plating GN is homogeneously dispersed in the acrylate PSA. The electrical conductivity of the ECAs increases to 3.14×10^-4 S/cm and the 180° peel strength and shear strength remains at a high level (180° peel strength about 0.58 MPa and shear strength about 0.48 MPa) when the content of Ni plating GN is 20 wt%.

Abstract: In this article, ultrasound was applied to the acid hydrolysis and oxidation of corn starch. The carboxyl content, viscosity of the starch prepared by the reaction under ultrasound and no ultrasound were studied through viscosimeter and titration method separately. The results showed that its carboxyl content of acid-thinned and oxidized corn starch with ultrasound was higher remarkably and increased by 14.81% at least, and its viscosity with ultrasound was evidently lower and decreased by not less than 37.78%, So ultrasound has a good performance in accelerating acid hydrolysis and oxidation of corn starch.

Abstract: In this article, new tussah silk fibroin films with nano-Mg(OH)₂were prepared. The composite films were characterized by SEM、DSC、TG、and IR. The experiment showed that the nano-Mg(OH)₂particle was dispersed in the regenerated silk fibroin. DSC revealed that the T_m of the composite films was increased. TG showed stability of the composite films could be increased .The experiment of IR showed that these conclusions were right.

Abstract: Using sulfate-modified titanium-bearing blast furnace slag (STBBFS) as photocatalyst, decolorization efficiency of methyl orange (MO) in the absence and presence of Cr(VI) were studied. The effect of the initial concentration of Cr(VI) on the decolorization efficiency of MO at pH=1.5 has been investigated. The results indicate that the acidic solutions are favorable for the photocatalytic oxidation of MO in the absence and presence of Cr(VI), and the optimum pH for oxidation of MO is 1.5. In the presence of Cr(VI), decolorization efficiency and adsorption efficiency of MO rapidly increased with the increase of Cr(VI) concentration, indicating a strong promoting effect of Cr(VI) to oxidation of MO. The increasing in decolorization efficiency of MO in the compound system can be attributed to three main reasons: (1) oxidation of MO by Cr(VI); (2) the high affinity of MO to catalyst surface; (3) Moreover, the addition of Cr(VI) species able to act as electron scavengers to catalyst surface promotes the effective separation of electron-hole in the photocatalytic processes, and hence promote the increase of decolorization efficiency of MO in Cr(VI)-MO system under visible irradiation. FTIR spectral analysis showed that all these characteristic peaks of Cr(VI) and MO disappear after photoreaction, indicating the degradation of Cr(VI) and MO.

Abstract: The C, N, S-tridoped TiO₂ nanosheets are synthesized via hydrothermal synthesis and post-treatment, and characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS), and UV–vis diffuse reflectance spectroscopy. The UV-diffuse reflectance spectra of all the C, N, S-tridoped TiO₂ nanosheets greatly extends the absorption edge into the visible light region, which can be attributed to C, N, S-tridoping in the form of cation C-doping, interstitial N-doping, anionic S-doping, and adsorbed SO₄^2- ions states. The C, N, S-tridoped TiO₂ nanosheets exhibits high visible light photocatalytic activity, and the xanthate concentration reduce as much as 100% in 120 min. All these indicate that C, N, S-tridoped TiO₂ nanosheets photocatalysts are promising visible light photocatalyst for the practical application.