Advanced Materials Research Vol. 826

Abstract: In this paper, a new method for the preconcentration and separation of cobalt was described. The methodology combines determined using an atomic absorption spectrometry (FAAS) with adsorption and desorption of cobalt on the modified bentonite using dithizone (Bent-dithizone). The operation conditions for the pre-concentration and separation of the cobalt, including pH, contact time, eluent condition and co-existing ions have been investigated. The result showed that the cobalt ion could be adsorbed by Bent-dithizone. The adsorption quantity was affected by the pH value of medium and shaking time. In the medium of pH 6.0, the adsorption capacity of Bent-dithizone to cobalt ion was 18.12 mg·g^-1 when the shaking time was 15 min. The cobalt adsorbed on the adsorbent could be completely eluated and recovered using 10 g·L¹ EDTA solution. The enrichment factor was more than 100. The detection limit of cobalt was 0.46 ng·L¹.The purposed method has been applied to the pre-concentration and separation of cobalt in the water sample, the recovery 97.94%-101.6%.

Abstract: Following the mechanism of heterogeneous nucleation, orthosilicate nuclei deposited on surface of fly ash micro-bead, forming a shell with micro and nanoscale structure, just like nanoscale structure on lotus leaf. Optimized coating-reaction condition is discussed. These composite micro-beads can be used for cheaper super-hydrophobic coating.

Abstract: A new microwave heating method for reparation of SrNiO₃ photocatalyst material was described. The optimum preparation conditions are that the microwave power is 560W, the microwave heating time is 30min, the calcination temperature is 700°C and the calcination time is 5h.The compound was measured by X-ray diffraction. In visible light and under the conditions of simulated fuel waste water, the photocatalytic properties of the catalyst material have been studied. The results showed the photocatalytic material prepared by that microwave heating have a high photocatalytic performance of degradation, and the degeneration rate of the dye may reach 98%.

Abstract: Nano SiO₂/ cenoshpere composites were prepared to obtain the core-shell structure by chemical precipitation and heterogeneous nucleation. This kind of composites can be further used to fabricate super-hydrophobic surface. In this study, industrial fly ash cenoshpere and water glass solution were used as raw materials. The aim was to coat a layer of Nano SiO₂ on the surface of cenosphere. By tests of SEM, XRD, FTIR, XPS, the mechanism of coating process was discussed. Treat the composites with KH-570, and then use this kind of particles to prepare super-hydrophobic surface.

Abstract: Composite particles with ultra-high molecular polyethylene (UHMWPE) matrix core and acetylene black (ACB) shell were produced by particle composite system (PCS), and molded into conductive polymer composites. Morphology of these composite particles was investigated by SEM. Matrix particles were coated by ACB nanoparticles very well. Conductive networks of ACB in polymer composites were seen by SEM. The results of electrical behavior study show that the polymer composites exhibit low percolation threshold and its electric conductivity is less affected by temperature due to unusual ACB distribution. Related mechanism is discussed.

Abstract: The modified and unmodified magnesium hydroxide whiskers (MH) were mixed with PE, PP, ABS matrix respectively. The mechanics performance of MH/polymer composites was tested by the universal testing machine. The effect of modified and unmodified MH whiskers addition on the performance of composite material mechanics was studied. The results show that the whiskers modified by sodium stearate had a significant mechanical improvement to the MH/PE, MH / PP and MH/ABS composites than unmodified whiskers. The content of modified MH whiskers added to PE, PP, ABS matrix materials are different when the best comprehensive mechanical properties are obtained, which are 20%20% and 40% respectively. Overall, the modified MH whiskers had a significant enhancement effect on the general plastics and engineering plastics.

Abstract: This study synthesized silicon emulsions by emulsion polymerization, mainly focused on how influencing factors including catalyst, emulsifier, reaction temperature and synthesis process could affect product conversion rate, appearance and molecular weight. The result showed that the conversion rate of the first 2 hours increased rapidly and became stable afterwards. Molecular weight increment was proportional to the extension of the reaction time. The silicon emulsions could achieve high convention rate and stability while applying 5% catalyst DBSA and 3% emulsifier (OP-10: SDS = 1:2) of Octmethyl cyclotetrasiloxane(D4) under an reaction temperature of 80 °C.

Abstract: Tourmaline is the floorboard of the mineral tourmaline family with piezoelectricity and thermoelectricity^[. In 1989, Japanese scholars Kubo found tourmaline spontaneous permanent electrode^[,which led to a new boom of tourmaline development and research. Tourmaline, as the prospect of new mineral materials, has the attention of the scientists from multiple disciplines and has obtained great development in environmental protection, electronics, medicine, chemical industry, light industry, architecture and other fields. The domestic research on tourmaline resources development and utilization is limited. The mineral dressing method are mainly two kinds: magnetic separation and flotation separation.

Abstract: CaO-ZrO₂ composite powders were synthesized by liquid phase coprecipitation using ethanol as reaction medium and washing solution. The green compacts were formed by dry pressing and were sintered by pressureless sintering. The morphology, size and distribution of the particles were studied by transmission electron microscopy (TEM); the microstructure of sintered bodies was analyzed by scanning electron microscopy (SEM), the density of green compacts and sintered bodies were tested by the mass and dimension. The results showed that 5 mol% CaO-ZrO₂ composite powders with good dispersion, particle size distribution were obtained. The fractured surfaces of sintered bodies prepared by the powders were smooth without any cracks. When contained 5-15mol% CaO, the relative density of sintered bodies exceeded 95%. When the molding pressure was 20Mpa, the relative densities of sintered bodies were all above 97%.

Abstract: ZnO nanorods were successfully synthesized using ZnCl₂ and NaOH as the starting materials without surfactants, template supporting and structure-directing solvent at low temperatures (20 °C 90 °C). X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) were used to analyze the crystal structure and surface morphology. Analysis of XRD patterns showed that ZnO clusters are single hexagonal phases of wurtzite structure with no other impurities. Also, TEM images revealed that the size of a single ZnO nanorod was between 32 and 60 nm in diameter and between 470 and 740 nm in length. Furthermore, the ZnO nanorods exhibited significant Raman spectrum optical properties suggesting that they have potential for opto-electronic application.