Advanced Materials Research Vols. 391-392

Abstract: The novel Ti/PbO₂ electrodes have been prepared by electrodeposition and anodization. The electrodes were characterized by SEM, XRD and linear sweep voltammetry (LSV). The SEM and XRD analysis reveal that Sn in the Pb-Sn alloy changes the β-PbO₂/α-PbO₂ ratio and the structure of the PbO2 layer. Sn content in Pb-Sn alloy is beneficial for the formation of β-PbO₂. LSV analysis shows that the novel Ti/PbO2 electrodes have high oxygen evolution potential, which can reach 1.75V.

Abstract: Bastnaesite was activated at low temperature, and the results of XRD, SEM and Raman showed that the particle size of minerals increased firstly, and then decreased with increasing of temperature. The polarization of rare earths fluoride decreased in activation minerals. Using HCl leaching, the rare earths carbonate and rare earths fluoride were separated effectively, and 94.6% rare earths carbonate and only 0.07% rare earths fluoride was dissolved respectively. The results supplied a new method of bastnaesite decomposition.

Abstract: Pure BiVO₄, Sm doped BiVO₄ have been prepared by chemical precipitation method and characterized by the techniques such as XRD and SEM. The photocatalytic degradation of methylene blue (MB) in aqueous solution was used as a probe reaction to evaluate pure BiVO₄, Sm doped BiVO₄ photocatalytic activity. The results show that doping of Sm decreases the diameter of BiVO4 nano-particles and significantly enhance the photocatalytic activity of BiVO₄. When the 0.2% Sm doped, the BiVO₄ degradation rate reaches 92.8%.

Abstract: The W/O/W double emulsion was prepared using Span-80 as surfactant, tributyl phosphate (TBP) as extractant, NH₃•H₂O solution as internal aqueous phase and kerosene as diluting agent. Simultaneity extraction of Iron and Nickel are from acidic leaching solution of laterite ones with the emulsion liquid membrane. The effects of various factors on the extractive result have been examined and discussed. The suitable composition of liquid membrane was: Span-80=5 %; TBP=4 %; NH₃•H₂O =2 mol/L; kerosene =89 %. And technological operating condition was determined as follows: Roi=1:1; Rew=1:3; sulphate solutions in external phase are 0.1mol/L. Under the optimal operation conditions, the secondary extraction efficiency of Nickel (II) and Iron is onto 90%.

Abstract: Polycrystalline TiO₂ nano-films were prepared by DC magnetron sputtering at different Ar/O₂ flow ratios. The thicknesses of all the prepared films were about 200 nm. The prepared films consist of a mixture of anatase and rutile phase. The TiO₂ nano-films deposited at Ar/O₂ flow ratio (1:1) have the best crystallinity and the mixture phase of anatase and rutile. SEM images show that the film surface composed of polygonal particles about 100 nm in diameter. UV–Vis transmission measurements reveal that the band gap of the deposited TiO₂ nano-films changed from 3.01 to 3.12 eV. The photocatalytic activities of the TiO₂ films were investigated by the decomposition of IPA under UV irradiation. The IPA can be oxidized to acetone and further to CO₂. The maximal acetone concentration and CO₂ concentration can reach to 29.2 ppm and 4 ppm after 120 min.

Abstract: The newly sulfated nanosolid superacid TiO₂/SO₄ prepared by sol-gel method was broadly characterized by acid base titration, XRD and TEM, which identified that the superfine solid TiO₂/SO₄ showing good dispersibility with average size of 27 nm belongs to kind of crystalline nanoparticles. With the help of the catalyst TiO₂/SO₄, the optimal reaction condition for direct transformation of pyrazole and nitrosonitric acid into 3, 5-Dinitropyrazole was n (pyrazol)=0.10 mol, m (TiO₂/SO₄ )＝1.5g, V(n-octannol)＝90mL, and V(nitrosonitric acid)＝50mL. Moreover, the optimal yield of the catalytic reaction reached up to 59.4% when the reaction time is 7 hours. The nanosolid superacid catalyst is still of high activity after regenerating eight times by calcination at 600^。C.

Abstract: Liquidus temperature, electrical conductivity and phase composition of Al₂O₃-CaO-Na₂CO₃ slag were studied in the paper. The results showed that the minimum value of liquidus temperature was 1429°C when the content of Na₂CO₃ was 11%. The Al₂O₃-CaO-Na₂CO₃ slag of lower liquidus temperature had higher electrical conductivity, and the electrical conductivity of Al₂O₃-CaO-Na₂CO₃ slag increased with the increase of temperature. The main phases of Al₂O₃-CaO-Na₂CO₃ slag are composed of CaAl₂O₄, Ca₃Al₁₀O₁₈, NaAlO₂ and Na₂CO₃. The addition of Na₂CO₃ is to be more effective for decreasing liquidus temperature and increasing electrical conductivity in the Al₂O₃-CaO-Na₂CO₃ slag system.

Abstract: Effects of commonly used initiator systems of grafting copolymerization on pulp fiber with caprolactam were studied in this paper. The systems were listed as below: potassium persulphate-sodium bisulfite, cerium nitrate amine, potassium permanganate, hydrogen peroxide-ferrous sulfate and benzoyl peroxide. According the grafting ratio as the main parameter, the optimal initiator system was used in the grafting copolymerization of cellulose fiber with caprolactam, which was picked under the same conditions including the same monomer concentration, the same temperature and the same reaction time. The results showed that it can obtain a higher grafting ratio at low temperature, and low reaction activation energy with a faster reaction rate in the oxido-reduction system (K2S2O8-NaHSO₃). And the reactant could expand in a short time. The K₂S₂O₈-NaHSO₃ initiator system is higher in graft ratio, rapid in speed and low in cost.

Abstract: In this paper, we briefly introduce the concept, composition and classification of nano-fluorocarbon-based magnetic fluids; then discuss preparation and structure of perfluoro polyethers (PFPE); and then analyze the infrared spectrum to infer the structure contained in the polymer in detail and systematically, further verify the functional group of PFPE.

Abstract: Soil erosion always leads to decreasing of land productivity, deposition of channels, lakes and reservoirs, pollution of water quality and so on. In the small watershed management, the soil erosion amount should be definite. The erosion modulus is able to quantitatively characterize the average extent of soil erosion. In practice, it is difficult to ascertain the erosion modulus. Several methods to ascertain erosion modulus are introduced in this article. Taken some small watershed of Yellow River in West Henan region as an example, these methods are testified to be feasible in ascertaining the erosion modulus. In the construction of small watershed dam system projects and planning and design of hydro junctions, methods and thoughts can be provided for the determination of the erosion modulus.