Advanced Materials Research Vol. 699

Abstract: Using sulfhydryl cotton for preconcentration of arsenic in Radix aucklandiae and determination of the arsenic by hydride generation-atomic fluorescence spectrometry. The samples were pretreated by high pressure digest. The experimental conditions such as negative high-voltage of instrument, preconcentration conditions and separation conditions of arsenic were studied and optimized. There was a good linear relationship between the fluorescence intensity and arsenic concentration in the range of 0-10μg/L with a correlation coefficient of 0.9997, while the detection limits was 0.06μg/L, and the relative standard deviation was 1.7% .The content of arsenic in the samples was 68.9-252.3µg/kg and the recovery was 90.0-95.0%.

Abstract: The cadmium in the Radix aucklandiae was determined by hydride generation-atomic fluorescence spectrometry after the Radix aucklandiae was treated by high pressure digestion. The effect of cobalt chloride to determination of cadmium by atomic fluorescence spectrometry was studied in this paper. The linear relationship was best when the concentration of cadmium standard solution at 0-10ug/L. The linear equation of standard curve was If=290.50×C+19.06. R= 0.9996,while the detection limits was 0.49ng/L,with a relative standard deviation of 0.37% .The cadmium content in the Radix aucklandiae was 56.8-72.3µg/kg with a recovery range of 81.6%-87.2%.

Abstract: Mixed fatty acids collector (JZQ - F7) prepared with catering waste oil applying for recovery of low grade phosphate rock is studied. Research shows that the environmentally friendly collector JZQ - F7 has high selectivity for phosphate ore with good solubility in water. The reagent could upgrade the ore P₂O₅ content from 2.57% of the run-of-mine to 32.25% of that after a rough and two clean flotation processes with Na₂CO₃ dosage of 2.1 kg/t, Na₂SiO₃.9H₂O dosage of 2.7 kg/t, JZQ - F7 dosage of 0.7 kg/t. The mesh of grind is 30% minus 200 mesh, and plus 40 mesh (0.45 mm) sizing product is discarded.

Abstract: Magnesium carbonate whisker is a single crystal of magnesium carbonate crystal, which has an integral crystal growth, and small defects, furthermore, it is colorless, transparent, and has high-intensity. It has an incomparable property compared to other conventional whiskers. It is a cost-effective whisker; thus has been of great interest due of this characteristic. Reported magnesium carbonate whiskers have been increased gradually since the beginning of this century. The preparation of magnesium carbonate whisker can be done by using chemicals as raw material, as well as by using natural resources, such as: seawater concentrated liquid and magnesite. Although magnesite resources are abundant in China, its low exploitation and utilization had long been the reason for low grade ore problems. The use of magnesium ore to optimize conditions for the preparation of magnesium carbonate whisker by adjusting reaction conditions, not only took advantage of mineral resources, but also helped to achieve industrial production of magnesium carbonate whiskers. We also analyzed how some factors had influenced the morphologies of MgCO₃•3H₂O, such as: reaction temperature, reaction time, and stirring speed etc.

Abstract: A multilayer TiO₂ film featured with gradual scattering structure was developed and used as photoelectrode for dye-sensitized solar cells. This structure of film consists of P25 nanoparticles and TiO₂ aggregate which was synthesized by micro-emulsion method as scattering centers The scattering centers were deposited by gradually increasing the amount from the film’s bottom to its top. The special films were used for the studies on the photovoltaic performance of N719 and Zn-3, and their photoelectric conversion efficiencies were 7.34% and 4.04%, respectively. Furthermore, more improvement of the conversion efficiency is realized for Zn-3 than for N719 by using our newly developed multilayer films as photoelectrode compared with ordinary photoelectrode.

Abstract: Bagasse, a fibrous residue from sugarcane juice extraction, was used as a reducing agent to roast low-grade pyrolusite in N₂. The roasted ore was further leached using sulfuric acid, to convert manganese oxide in the ore to manganese sulfate. The effects of weight ratio of bagasse to manganese ore, roasting temperature, roasting time, leaching temperature, leaching time, stirring speed and sulfuric acid concentration on the leaching recovery of manganese were investigated. Optimal conditions were determined to be a bagasse to manganese ore weight ratio of 0.8:10, roasting temperature of 500°C for 40 min, leaching stirring speed of 100 rpm, sulfuric acid concentration of 3 mol•L^-1 and leaching temperature of 50°C for 40 min. The leaching recovery rate of manganese was up to 97.8% at the optimal conditions.

Abstract: A new Triton X-114 cloud point extraction combined with fluorometry method for analysis of magnolol in drug samples was developed. Under the optimum conditions, the calibration graph was linear in the range of 2.0-150.0ng/mL of magnolol in the initial solution with r = 0.9998. Detection limit (DL) was 0.03ng/mL (S/N=3) and the relative standard deviation (RSD) for 20.0ng/mL of magnolol was 2.79%(n=11). The method was successfully applied for the determination of magnolol in drug samples with satisfactory results.

Abstract: Self-assembly of polyazamacricyclic complexes of copper(II), [Cu(H₂L¹]⁴⁺, where L¹ = 1,8-bis(2-aminoethyl)-1,3,6,8,13-hexaazacyclotetradecane, and [Cu(H₂L²)]²⁺, where L² = 1,8-bis(4-butylic acid)-1,3,6,8,13-hexaazacyclotetradecane, [Ni(CN)₄]^2- produces two-dimensional permanent ring structure (1) and three-dimensional network structure (2), respectively, in crystalline solid. The geometry around copper(II) ion is an z-elongated octahedron (1) and square pyramid (2). Inter molecular hydrogen bonding of 1 produces one-dimensional ring chain and 2 produces one-dimensional zig-zag shape coordination polymer. Hydrogen bonding of neighboring chains of 1 produces two-dimensional permanent ring structure with a nanoscale area and that of 2 produces three-dimensional network structure having one-dimensional channels with nanoscale cross-section in crystalline solid.

Abstract: Organic/inorganic support for immobilizing hybrid catalyst (Cp₂ZrCl₂/ TiCl₄) was devised. Silica was the inorganic part using in the immobilization of Cp₂ZrCl₂. Subsequently, styrene and acrylic copolymer (PSA) was coated on the silica. TiCl₄ was finally supported on the PSA. PSA layer played obvious barrier ability to triethylaluminium (TEA) in the support which was observed by ethylene polymerization. This outstanding barrier property dramatically restrained the toxic effect of TEA to Cp₂ZrCl₂. Thus, the property of Cp₂ZrCl₂ could be maintained using cocatalyst TEA. Bimodal polyethylene was achieved cocatalysted by TEA.