Applied Mechanics and Materials Vols. 448-453

Abstract: A hydrogen-bond donor resin HX was obtained by modifying resin H103 . The adsorption effect of resin HX on berberine was determined. The adsorbing kinetic and dynamic mechanisms of resin HX and resin H103 was compared. The results showed that, after modification, resin HX could form hydrogen-bond with berberine molecules. In the adsorption process, two C-O groups on berberine molecules became the electron acceptor of hydrogen-bond and the N-H group on resin molecules became the electron donor of hydrogen-bond. The existence of hydrogen-bond enhanced the adsorption force, and led to bigger amount of adsorption.

Abstract: The key step is improved the national standards-the molybdoantimonyarsenate blue spectrophotometric method for the determination of arsenic content in tin smelting waste residue. The experimental results show that on the basis of GB/T 1819.5-2004, the reaction acidity instead 2.0mol/L, tartaric acid 10mL, coloration in water bath 20min, then colorimetric at wavelength of 850nm are the optimal conditions for determination. Using three samples of tin slag smelting arsenic verification of these conditions, precision and accuracy are good, the relative standard deviations are 0.91%、1.35%、1.07%, the recoveries are 100.01%、99.73%、99.98%, respectively.

Abstract: Size-controllable synthesis of worm-like microporous monodispersed SiO₂ microspheres using dodecylamine (DDA) as direct agent in ethanol-water solvent system was firstly developed by varying the proportion of reactants. The products were characterized with scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), small angle X-ray diffraction (SAXRD) and nitrogen adsorption. The results showed that the SiO₂ microspheres with size of 50nm~1um could be prepared by varying the molar ratio of water/ethanol when the molar ratio of (DDA)/tetraethyl orthosilicate (TEOS) is 0.4 and the concentration of TEOS varied from 0.138 to 0.248mol/L. This method is simple and convenient, the prepared SiO₂ microspheres are monodispersed and uniform, the worm-like pore size is about 1.4nm. The size controllable silica microspheres could be used as an excellent additional medium to alter rheological behavior of fluid after surface modification..

Abstract: PHB (Poly-β-hydroxybutyrate) has been widely in the areas of industrial packaging, pharmacy and agriculture. Currently, its production cost, especially in extraction and purification are high. A moderate halophilic bacterium was used for PHB synthesis and an aqueous extraction method based on osmotic downshock was investigated in this paper to further improve the extraction efficiency. PHB synthesised by moderate halophile with certain NaCl concentration can be released with cell lysis by osmotic downshock. Meanwhile the high temperature, ultrasonic and SDS (Sodium dodecyl sulfate) can enhance the release. After 48 h of fermentation, the production of PHB by Halomonas salina was 6.5 g/L. The extraction rate of PHB was 24.6% with osmotic downshock and 35.4% with additional ultrasonic assistance at 65 °C. A further addition of 0.5% SDS made the extraction rate increase to 75.4%. Thereinto, the addition of 6% NaCl had significantly improved the aqueous extraction rate to 92.3%.

Abstract: This study describes the absorption, transmission and reflection spectra of Ag/Ti/SiO₂ balls/glass and CHCl3:Alq3/Ag/Ti/SiO₂ balls/glass structures with 200 ~ 650nm SiO₂ balls, respectively. The enhanced fluorescence in a CHCl3:Alq3 (60nm)/Ag (70nm) / Ti (5nm) /SiO₂ balls /glass structure using by surface plasmons when the light was irradiated from the backside was observed. It can be applied to improve bio-plasmonic device, organic light emitting diode and solar cell optical devices efficiency.

Abstract: Pure and F, Fe-codoped TiO₂ were prepared by sol-hydrothermal process, in which titanium (IV) n-butoxide, Fe (NO₃)₂·6H₂O and NH₄F were used as precursors. And the samples were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), and N₂ adsorption-desorption method. The results showed that the F, Fe-codoped samples were principally single-phase anatase structures, and the particles possessed higher BET area than that of pure TiO₂. The photocatalytic activity and reusability of the catalysts under UV light (365nm) was investigated with neutral red as the model compound. The results showed that F (2.0%), Fe (4.0%) codoped TiO₂ had the highest photocatalytic activity among all as-prepared samples. The kinetic study showed that this photocatalytic process coincided with the Langmuir-Hinshelwood (L-H) pseudo first order reaction model.

Abstract: In this paper, coal fly ash was modified by the hydrothermal synthesis method based on sodium hydroxide solution, and then was macerated by ethanol amine. Then we obtained the solid amine adsorbents used to absorb CO₂. The modified fly ash was investigated by scanning electron microscope (SEM) and the specific surface area analyzer (BET) for the microstructure and specific surface area. Then, the solid CO₂ adsorbent was analyzed by fourier transform infrared spectrometer (FT-IR) and thermal analyzer (TGA) in CO₂ atmosphere. Results showed that modified fly ash generated many kinds of zeolite material by the SEM and the BET analysis, greatly increasing the specific surface area, improved the adsorption capacity. FT-IR analysis that the surface of solid amine CO₂ adsorbent with amine groups; TGA analysis that compared with the original fly ash, CO₂ adsorbent by this paper made has the capability of adsorption of CO₂.

Abstract: Bi₂WO₆-WO₃ heterojunctions were first prepared using hydrothermal method with the assistance of cetyltrimethylammonium bromide (CTAB). And Bi₂WO₆-WO₃ was further fabricated by depositing Pt on the surface using the photo-assisted deposition method. These catalysts were characterized by XRD, SEM, FTIR, BET and DRS. It is found that Pt-Bi₂WO₆-WO₃ acting as a novel visible light-driven photocatalyst exhibited excellent photocatalytic activity in degradation of Methyl Orange (MO) under visible light irradiation. The highest photocatalytic activity of Pt-Bi₂WO₆-WO₃ photocatalyst is attributed to the synergistic effect of Pt surface plasmon resonance and Bi₂WO₆-WO₃ heterojunction structure.

Abstract: Highly mesoporous active carbon for removing methylene blue (MB) from aqueous solution was prepared from pyrolyzed rice husk by combination of CO₂ activation and NaOH-solution boiling. The preparation method was found to be alkali-saving and equipment-friendly. The prepared active carbon exhibited high mesoporosity (79.1%), with mesopore volume and specific surface area up to 0.619 mL/g and 899 m²/g, respectively. At initial MB concentrations of 240-380 mg/L, the MB removal efficiency of the prepared active carbon ranged from 92% to more than 99%, fairly comparable to that of the highly mesoporous commercial active carbon used for reference. The adsorption of MB onto the prepared active carbon well followed the pseudo second-order kinetic model and Langmuir isotherm. This study indicated that highly mesoporous active carbon with large dye removal efficiency could be prepared from rice husk by an alkali-saving and equipment-friendly process.

Abstract: Compared with the treatment of heavy metal waste water by bamboo charcoal and modified bamboo charcoal. The mainly types and methods of modified bamboo charcoal adsorption of pollution water is introduced. some important factors that effecting the bamboo charcoal and modified bamboo charcoal adsorption of heavy metal pollution were described in detail, summarizes the desorption method of the specific adsorbent and adsorption mechanism.