Advanced Materials Research Vols. 750-752

Abstract: The present study describes degradable polyurethane (PU) microspheres fabricated using toluene diisocyanate, polycaprolactone, polyethylene glycol, 2, 2-hydroxymethyl-2-propionic acid and triethylamine for drug delivery. The novel microspheres were synthesized using self-emulsion and condensed phase separation method. Fourier-Transform Infrared Spectrum analysis (FTIR) was performed revealing the chemical structure of polyurethane microspheres with special chains changing. Swelling properties influenced by solvent polarity, PEG content, PEG molecular weight, were evaluated, suggesting that the swelling ratio (SR) of PU microspheres increased with the increase in solvent polarity, PEG content and PEG molecular weight respectively.

Abstract: Fe-Ce-N tri-doped TiO₂ photocatalyst was prepared by sol-gel method using tetrabutyl titanate as precursor. The optimal doping amount and calcinations temperature were determined. The prepared catalyst was characterized by X-ray diffraction (XRD) and UV-Vis diffuse reflectance spectroscopy, and the photocatalytic activity was evaluated by means of the degradation for methyl orange (MO) under UV light and daylight irradiation. The results indicated that the optimal doping amount was 1.0% N, 0.25% Fe and 0.05% Ce, and the appropriate calcination temperature was 400°C. XRD analysis showed that TiO₂ existed in anatase phase completely. UV-Vis adsorption spectrum showed that Fe-Ce-N tri-doping resulted in a intense adsorption in the near UV and visible-light region and a red shift in the adsorption edge from UV range to visible range of 400-500nm. The photocatalytic activity of Fe-Ce-N tri-doped TiO₂ under UV and daylight irradiation was very higher than that of bi-doped Fe-Ce-TiO₂, Fe-N-TiO₂, Ce-N-TiO₂ and undoped TiO₂. The significantly higher activity of Fe-Ce-N tri-doped TiO₂ may be due to the synergetic effect of Fe, Ce and N in the tri-coped TiO₂.

Abstract: Catalytic hydrolysis decomposition of dichlorodifluoromethane (CCl₂F₂) in the presence of water vapor and oxygen was studied over solid acid MoO₃/ZrO₂ using a fixed-bed reactor. The adsorption velocity equation was calculated by Bangham Equation. Reaction energy was determined by Arrhenius Equation and it was 123.12 KJ.mol^-1.

Abstract: The difference of Cu-Co-Mn mixed oxides and hopcalite as support in synthesis of diphenyl carbonate by oxidative carbonylation of phenol was studied. The catalysts were characterized by transmission electron microscopy, scanning electron microscopy, X-ray power diffraction, and X-ray photoelectron spectroscopy. The results show that the average particle diameter of the former catalyst is about 40 nm, whereas the other catalyst is about 0.5 μm. The main crystal phase in the former catalyst is Co₂MnO₄ and Pd_0.5Pd₃O₄, which in the latter catalyst is CuMn₂O₄, CoMn₂O₄ and Pd_0.5Pd₃O₄.The oxygen atoms lose electrons and form oxygen vacancies in.Pd_0.5Pd₃O₄ and Co₂MnO₄ of the former catalyst, which destroys the crystal integrity and prompts the oxygen adsorption on the crystal surface. The oxygen atoms lose electrons and form oxygen vacancies in.Pd_0.5Pd₃O₄ of the latter catalyst. Finally, it was found that the difference of the yield and selectivity of the both catalysts was not remarkable.

Abstract: Hopcalite mixed oxides were used as support of the catalyst for the synthesis of diphenyl carbonate (DPC) by oxidative carbonylation of phenol .The catalyst was characterized by scanning electron microscopy (SEM), X-ray power diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results show that the size of the particles is well-distributed and the physical structure is favorable, which contribute to the reaction efficiently. The main crystal phase in catalyst is CuMn₂O₄, CoMn₂O₄ and Pd_0.5Pd₃O₄, and the valency of Mn and Co remains unchanged. Finally, the synthesis of DPC was carried out and it was found that the yield and selectivity could reach 43.5% and 99.6%, respectively.

Abstract: Steel-making slag haydite was prepared with steel slag and clay. Bath sorption experiments were carried out to study the adsorption characteristic of steel-making slag haydite for phosphorus (P). The results show that the adsorption process of steel slag haydite for P conforms to pseudo-second-order kinetic equation, and the activated energy was 41.52KJ/mol. Isothermal adsorption process conforms to the Laguir equation , and at 20°C ~ 40°C, the maximum P uptake value increased from 1.166 mg/g to 2.422 mg/g. Both kinetic and thermodynamic studies indicate that chemical adsorption is the dominant mechanism for P removal which would be promoted by heating-up, and the reaction is heat-absorbed, thermal charge-increasing and spontaneous.

Abstract: Nanoporous materials with organic frameworks (3PDVB/MA-1) have been successfully synthesized in the microchannel through solvothermal polymerization of divinylbenzene and methacrylic acid in the presence of tetrahydrofuran. The material has (3PDVB/MA-1) disordered mesopores with uniform pore size (~50 nm) and high BET surface area (415 m²g^-1). In the adsorption of heavy metal cations Co²⁺ in wastewater, the mesoporous resins exhibit superior performances, and thus have great potential in water treatments.

Abstract: Urbanization, economic growth, and the continuing improvement in living standards have all contributed to the increase of municipal solid waste. More effective technology is needed to improve the conditional landfill of municipal solid waste. Multifunctional microbe community introduced in bioreactor landfill accelerates the degradation of leachate of MSW( Municipal Solid Waste). The results show that introduced microbes shorten the acid formation phase effectively, 208 days earlier than contrast group; introduced microbes accelerated the degradation of leachate. Concentration of COD of leachate decreases significantly and remains 3000 mg/L after 505^th day, 187 days earlier than contrast group. Concentration of ammonia nitrogen of leachate decomposes more rapidly (63 days earlier) and finally reaches 0.025 g/L at 700^th day that meets the national pollution - control requirements of MSW (GB 16889-2008).

Abstract: In this paper, the chemical-thermal composite of coal gangue activation and influence factors is studied. Using adopting Al³⁺ dissolution rate as an evaluation index to determine the activation conditions, XRD is used to determine the crystal structure and SEM scanning electron microscopy (SEM) for crystal morphology. The results shows that the best activation conditions of calcination for coal gangue activation time is1.5h, under the condition of calcination temperature 650°C, water cooling, the Al³⁺ dissolution rate can reach 70.14%.After activation of coal gangue, the kaolinite convert directly into cetakaolinite, its active composition SiO₂ and Al₂O₃ present loose shape, good activation, can be used as an adsorbent and catalyst materials.

Abstract: A series of aliphatic biodegradable poly (butylene succinate-block-butylene sebacate) (PBSuBSe) copolyesters were synthesized by incorporation of PBS_e into the PBS_u molecular chains. The molecular weight, crystallization behaviors and the crystal structure of the copolyesters were investigated by using gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WAXD), respectively. The copolyesters might be potentially useful as the biodegradable materials.