Advanced Materials Research Vol. 549

Abstract: A robust, accurate and sensitive analytical procedure was developed for the simultaneous determination of trace Antimony and Bismuth in Jilin ginseng by hydride generation atomic fluorescence spectrometry. The parameters were studied systematically, such as acid concentration of the reaction medium, flow rate of the carrier gas and shield gas, the atomizer of height, etc. Ascorbic acid and thiourea were used as reducer or masking agents to enhance the generation efficiency of the volatile species of Sb and Bi. In the presence of thiourea and ascorbic acid, the influences of some coexisting elements on the determination of antimony and bismuth were investigated.

Abstract: SrFe_xCo_0.5O_δ (x=0.5, 0.75, 1.0, 1.25) mixed metal oxides were synthesized by the citrate method. The structure and thermo-chemical stability of the obtained SrFe_xCo_0.5O_δ powders were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD results show that the SrFe_xCo_0.5O_δ powders are composed of perovskite-type cubic structure at both room temperature and high temperature. The crystalline phases of the SrFe_xCo_0.5O_δ powders are dependent on the content of Fe and SrFe_0.5Co_0.5O₃, SrFe_0.19Co₀₈₁O_2.78 are the main crystalline phases. The powders have good thermo-chemical stability at elevated temperatures in helium, which is confirmed by an in-situ high-temperature X-ray diffraction. The SEM images show that the product of the SrFe_xCo_0.5O_δ (x=0.5, 1.0) is composed of single grain, while other two samples consist of layer structures and some open porosities.

Abstract: In this paper, a starch-based dispersant for Chinese Shenhua coal-water slurry (CWS) was synthesized by radical polymerization using styrene sulfonate and acrylic acid as graft monomers in oxidation-reduction initiator system. Chemical structure and thermal performance of the copolymer were investigated by Fourier Transform Infrared Spectrum (FT-IR) and Thermogravimetric Analyzer (TGA). The rheological characteristics of the slurry were studied by varying dispersant dosage and shear rate，and the results show, At coal concentration of 66 wt%, dispersant dosage of 0.4 wt% and shear rate of 100 s^-1, the CWS gives the minimum viscosity of 848 mPa•s. Bleeding ratio tests indicate the dispersant can stabilize the slurry. Based on the above, the starch-based dispersant has due structure and a bright prospect for the application for CWS.

Abstract: A new amphiphilic copolymer of hydroxyethyl cellulose and poly(p-dioxanone) (PPDO) was prepared through the ring-opening copolymerization in IL 1-N-butyl-3-methylimidazolium chloride ([Bmim]Cl). The resulting products were thoroughly characterized with FT-IR, ¹H-NMR and TG. The copolymer is hopeful for the use as tissue engineering materials and the ionic liquid as the reaction media can be easily recycled and reused

Abstract: The adsorption of methylene blue (MB) from an aqueous solution by MCM-41 was investigated. It was found that the adsorption of MB on MCM-41 could be described by Freundlich isotherm and second-order kinetic model. The adsorbed amount of MB on MCM-41 reached to 24.5 mg g-1 within 30 min.

Abstract: Cadmium Selenide/Cadmium Sulfide (CdSe/CdS) core/shell quantum dots (QDs) in aqueous solution were prepared by solve-separate method using CdSe as core and mercapto-acetate acid as stabilizer and surfactants. The results of experiments indicate that the size of the CdSe/CdS QDs was about 5nm estimated by FE-TEM, which is accordant with that calculated from the XRD data by the Scherer equation after emendation. The QDs belong to the cubic structure (zinc blende) by XRD analysis. The intensity of luminescence of the quantum dots was greatly improved after the surface was coated with CdS shell. With increasing the time of refluence, the intensity of photoluminescence was promoted correspondingly. The excitation wavelength was 350nm, two emission peaks were clearly observed, the first high-energy peak was at 600nm and the second one located in 700nm. The first high-energy band was attributed to electron–hole recombination after relaxation and the second energy band was to deep traps in quantum-confined systems.

Abstract: Many methods to produce NPs have been studied. Among them, the molecular level understanding of the formation of solids in biological systems has provided inspiration for the controlled formation of novel inorganic materials. The use of a protein cavity as the growth field of NPs provides one candidate method for obtaining uniform particle size. The host-guest relationship between these protein cages and the encapsulated material is based primarily on a complementary electrostatic interaction. Charged interfaces play important roles in defining electrostatically distinct environments for spatially defined encapsulation. The electrostatic interactions can be approximated by Guoy-Chapman theory of charged interfaces. These interactions are proposed at the interior of protein cages such as ferritin and viruses. The protein cage with a highly charged interior surface with pores that allow molecular access to the inside of the protein could act as a constrained reaction vessel. The present paper will focus on the synthesis of Metal NPs using ferritin.

Abstract: A new highly selective poly vinyl chloride(PVC) membrane iodide electrode which has neutral carrier of cobalt(Ⅱ) complex with symmetrical binuclear schiff base has been studied. Based on the fact we knew that ethylenediamine could react to acetylacetone and salicylaldehyde. The electrode exhibited near -Nernst response to iodide with a slope of ―54.4 mV/dec over a wide concentration range (1.58×10^-7~1.0×10^-1 mol/L) with a detection limit of 6.3×10^-8 mol/L in phosphorate bufer solution with pH=2.4 at 26°C. After applied to the determination of iodide in pharmaceuticals and salts, the electrode could get satisfied results

Abstract: This paper introduces the current technology of separating and refining β-methylnaphthalene from wash oil. On this basis, I propose a new production method of β-methylnaphthalene after many experiments. Industrial methylnaphthalene is washed twice with sulfuric acid and is distilled once. The content of β-methylnaphthalene is higher than 96%.The yield is 60%, which is higher than current domestic production levels.

Abstract: A new fluorescent probe, quinoline derivative DPQ bearing a methyl pyrrolidine-1-carbodithioate group, was synthesized and characterized by IR, Tof-MS and NMR. Its fluorescent behaviors toward transition metal ions were investigated. The results indicate that DPQ shows unique selective and high sensitive for Hg2+ in aqueous solution with a broad pH range 4-10. DPQ forms a 1:2 metal-ligand complex with Hg2+ ions with a limit of detection as low as 1.7×10-6 mol/L.