Advanced Materials Research Vols. 881-883

Abstract: Manganese dioxide loaded active carbon absorbents (MnO₂/AC) were prepared. Mixture of H₂S and N₂ is used to evaluate the performance of absorbents in fixed adsorption bed for H₂S removal. A suitable H₂S removal activity was obtained with adsorbent of manganese dioxide to active carbon ratio of 1:1, drying temperature of 120°C, drying time of 24 h. The breakthrough time of 70 min with total gas volume of 1400 mL, adsorption temperature of 40°Cwere observed. Comparing with the unmodified active carbon, its breakthrough H₂S capacity increased by 96.9 mg·g^-1.

Abstract: The preparation and properties of alkyl betaine, alkyl amido betaine, α-long chain alkyl betaine, alkoxy betaine, ethoxylated betaine, and some betaine with special structures were summarized. The synthesis routes and properties of several betaines were compared. The application of betaine surfactants in chemical flooding was also reported.

Abstract: Reaction conditions of asymmetric Reformatsky reaction between cinnamaldehyde 1 and ethyl bromodifluoroacetate 2 were investigated. Finally, (1S, 2R)-N, N-dimethyl-2-aminol-1, 2-diphenylethanol (ligand C) was proved to be the best ligand for this transformation and up to 37% ee was obtained with THF as solvent in -40 degree.

Abstract: A porous copper/tungsten oxide (WO₃)/polyaniline (PANI) composite modified electrode CuWP was fabricated by electrochemical deposition of copper nanosheets on WO₃/PANI composite. The CuWP exhibited higher electrocatalytic activity for nitrate reduction than the similarly prepared copper modified electrode due to the larger surface area of CuWP and the synergistic catalytic effect of copper and WO₃/PANI. The linear scan voltammetry results showed a good linear relationship between nitrate reduction current and concentration of nitrate from 40 to 276 μM, with a sensitivity of 4.5 μA/μM and detection limit (S/N=3) of 1.2 μM. The CuWP modified electrode was tried to be employed in determination of nitrate in drinking water.

Abstract: Two bis (benzimidazoyl) monomers were synthesized, and Poly (N-arylenebenzimidazole ketone) s were prepared by N-C coupling reaction that replaced the NH sites from the bis (benzimidazolyl) derivatives with activated difluorides monomers in sulfolane at 210 °C. All the resulting polymers showed easy solubility compared with traditional polybenzimidazoles. Differential scanning calorimetry and thermogravimetric measurements showed that the polymers had high glass transition temperatures (>240 °C), good thermostability and high decomposition temperatures (>460 °C).

Abstract: An electrochemiluminescence (ECL) sensor for highly sensitive detection of diphenhydramine was developed by employing tris (2,2-bipyridyl) ruthenium (II) as the detector. The ECL sensor was fabricated by immobilizing ECL reagent Ru (bpy)₃²⁺ on the poly-(3,4-ethylene dioxythiophene) and polystyrene sulfonate composite film (PEDOT-PSS) modified indium tin oxides (ITO) electrode by electrostatic attraction strategy. The ECL sensor showed an increased ECL intensity in the presence of diphenhydramine. The increased ECL intensity was direct proportion to the concentration of diphenhydramine over a range from 5.0 ×10^-4 to 5.0 ×10^-6 mol/L. The detection limit for the detection of diphenhydramine was 1.0 ×10^-6 mol/L. Fabrication of the ECL sensor by this method is simple and easy, and hence has potential applications in the field of ECL analysis and detection.

Abstract: Using the Hartree Fock (RHF) method, we study the most reactive carbon atoms in the polycyclic aromatic hydrocarbons (PAHs). In order to identify the most reactive carbon atoms, the Mulliken charges and the Mayers bond orders were calculated as the criterion. The results demonstrate that the most reactive carbon atoms appear at the locations of the outer C in the inner benzene rings for cata-condensed PAHs, while for peri-condensed PAHs they are the outer C in the outer benzene rings。

Abstract: Novel La-doped BiVO₄ microcakes have been hydrothermally synthesized and characterized by XRD, XPS, SEM, and DRS techniques.The results reveal that the well crystallized and cake-like Bi_0.95La_0.05VO₄ monoclinic crystal with the diameter range of 15 μm and the width range of 0.2-0.8 μm can be obtained via a template-free hydrothermal route. Compared with pure BiVO₄ microcakes, Bi_0.95La_0.05VO₄ microcake shows a little red shift in the absorption band, resulting in a narrowed band gap (2.37 eV), which has the better photocatalytic activity with a 98.6 % degradation of methylene blue (MB) with a concentration of 10 mg/L under visible-light irradiation for 60 min.

Abstract: A new coumarin derivative 8-Dimethylaminomethyl-7-hydroxy-chromen-2-one (C₁₂H₁₃NO₃, M = 219.23) were prepared and characterized by single-crystal X-ray diffraction. The compound crystallized in methyl alcohol system. The crystal belongs to the Monoclinic system, space group P2₁/C, with a = 10.228(2) Å, b = 8.9260(18) Å, c = 12.064(2) Å, α = 90°, β = 91.85(3)°, γ = 90°, M = 219. 23, V = 1100.8(4) ų, Z = 4, Dc = 1.323 g/cm³, μ=0.096 mm^-1, F(000) = 464, R = 0.0594 and wR = 0.1611. A total of 2136 unique reflections were collected, of which 2020 with I > 2(I) were observed. The quantum chemistry calculation study on the title compound has been performed by quantum chemical method in SVWN5/6-31G^** level. Additionally, IR, ¹HNMR spectra, thermal analysis and the fluorescent properties are discussed .

Abstract: Density functional (B3LYP)and the second–order Møller–Plesset (MP2) theoretical method with differentbasis sets are used to investigate the geometricconfigurations of the D…CO (D=He, Ne, Ar, Kr andXe) complexes. The results showed that C end of the CO molecule can close and interact with D atom and formstable van der Waals complex, so does the O end of the CO molecule. It issuggested that the interaction between CO and D atom is not electrostaticinteraction in nature. The harmonic frequency analysesand Mulliken charge distributions of five complexes were performed at the MP2/aug-cc-pvtz/DGDZVPlevel.