Total Synthesis of α-Elvucitabine

Total synthesis of α-elvucitabine was achieved in 26% overall yield by a concise nine-step procedure starting from L-lyxose, with trimethylsilyl trifluoromethaneoulfonate (TMSOTf)–mediated stereocontrolled α-N-glycosidation and olefination through Barton–McCombie deoxygenation being the key steps, and the stereochemistry of the product was determined by nuclear Overhauser effect spectroscopy.     

The preparation and properties of bulk-heterojunction organic solar cells with indole-containing fulleropyrrolidine derivatives as acceptors

Two indole-containing fullerene derivatives, N-hydrogen-2-[3-(N-2-ethylhexylindolyl)][60]fulleropyrrolidine (EHIHC60P), and N-(2-ethylhexylindolyl))-2-[3-(N-2-ethylhexylindolyl)][60]fulleropyrrolidine (DEHIC60P) were synthesized by the typical Prato reaction. The absorption spectra, electrochemical properties of the two compounds were measured. Inverted solar cells were fabricated with the structure of ITO/ZnO/poly(3-hexylthiophene) (P3HT):fullerene derivatives/MoO₃/Ag. The highest power conversion efficiencies (PCEs) of 3.32% and 3.23% were obtained for P3HT/EHIHC60P and P3HT/DEHIC60P based solar cells at the composite ratio of 1:1 after the active layers were annealed at 150 °C under inert atmosphere, with a open-circuit voltage (V_oc) of 0.66 V and 0.74 V, respectively. For comparison, the device based on P3HT/PCBM at the same conditions showed the PCE of 3.28%, with a V_oc of 0.61 V. The influence on the photovoltaic property of the fullerene derivatives, which was induced by some subtle changes in the chemical structure was compared and discussed.     

Methanolysis of poly(lactic acid) (PLA) catalyzed by ionic liquids

Poly(lactic acid) (PLA) was depolymerized by methanol in the presence of a novel catalyst: ionic liquids. It was found that the purification method of the main products in the methanolysis catalyzed by ionic liquids was simpler than that of traditional compounds, such as sulfuric acid. Qualitative analysis indicated that the main product in the methanolysis process was methyl lactate. The influences of experimental parameters, such as the amount of ionic liquids, methanolysis time, reaction temperature, and dosages of methanol on the conversion of PLA, yield of methyl lactate were investigated. Under the optimum conditions, using ionic liquid 1-butyl-3-methylimidazolium acetate ([Bmim][Ac]) as catalyst, results showed that the ionic liquid could be reused up to 6 times without apparent decrease in the conversion of PLA and yield of methyl lactate. The kinetics of the reaction was also investigated. The results indicated that the methanolysis of PLA was a first-order kinetic reaction with activation energy of 38.29 kJ/mol. In addition, a possible catalysis mechanism of the methanolysis of PLA was proposed.     

General Route to Synthesize Monodisperse Oxide (Hydroxide) Nanoparticles

Mono-dispersed oxide and hydroxide nanoparticles have been synthesized through the solvothermal process in alcohol-water mixtures. The products were characterized by powder x-ray diffraction (XRD) and scanning electron microscopy (SEM). Plate-like nanoparticles are obtained for Bi₂O_2.33, Fe₂O₃, and Cd(OH)₂, and spherical nanoparticles are obtained for SnO₂. The growth mechanism for the mono-dispersed nanoparticles has been preliminarily discussed.     

A Direct and Rapid Route to Synthesize Pd/Si‐MCM‐41 at Room Temperature

The pure silica mesoporous molecular sieve MCM‐41 was synthesized under hydrothermal conditions. Pd/Si‐MCM‐41 was prepared by the incipient wetness impregnation of pure silica MCM‐41 with mixed solution of PdCl₂, ethanol and CH₂Cl₂. The samples were characterized by x‐ray diffraction (XRD), transmission electron microscopy (TEM), and nitrogen adsorption–desorption isotherms at 77 K. The XRD and TEM results reveal that Pd is actually anchored inside the pores of Si‐MCM‐41 and the Si‐MCM‐41 structure is clearly maintained after impregnation.     

Surface and Catalytic Properties of K/V Catalysts Coating on Porous Al2O3 Substrate

The morphology of different ratio K/V catalysts supported on porous α‐alumina substrate was investigated by atomic force microscopy (AFM). Changes in the particle size distribution, pore size distribution were analyzed respectively using AFM software. In addition, their catalytic activities and compositions for carbon oxidation were studied by x‐ray diffraction (XRD), differential scanning calorimetry (DSC), and temperature‐programmed reactions (TPR). As a result, with the increase of K concentration, the mean particle size gradually increased and the mean pore size decreased. According to the catalytic activity studies, the catalytic activity of the KVO₃ and K₃V₅O₁₄ phases are more effective than KCl.     

Inhibition of CTAB on the Corrosion of Mild Steel in Hydrochloric Acid

The inhibition effect of cetyl trimethyl ammonium bromide (CTAB) on the corrosion of mild steel in 1.0 mol L^?1 hydrochloric acid (HCl) has been studied at different temperatures (25–60°C) by weight loss and potentiodynamic polarization methods. The results reveal that CTAB behaves as an effective inhibitor in 1.0 mol L^?1 HCl, and the inhibition efficiency increases with the inhibitor concentration. Polarization curves show that CTAB is a mixed-type inhibitor in hydrochloric acid. The results obtained from weight loss and polarizations are in good agreement. The effect of immersion time on corrosion inhibition has also been examined and is discussed. The adsorption of inhibitor on mild steel surface obeys the Langmuir adsorption isotherm equation. Thermodynamic parameters have been obtained by adsorption theory. The inhibition effect is satisfactorily explained by the parameters.     

Small‐Angle Neutron Scattering (SANS) Study of Magneto‐Vesicles

Small‐angle neutron scattering from magneto‐vesicles (MVs) prepared by extrusion was studied. Contrast variation allowed the determination of structure and sizes of the vesicles and the encapsulated magnetic nanoparticles, respectively. The results from MVs synthesized with a 0.3% volume fraction of citrate‐coated magnetic nanoparticles are compared to those of similarly prepared vesicles of the neutral lipid 1,2‐Dioleoyl‐sn‐Glycero‐3‐Phosphocholine (DOPC) (without magnetic particles), and magnetic particles not encapsulated in vesicles. It is observed that the bilayers of the as‐prepared MVs, and the encapsulated nanoparticles retain their structural properties, highlighting the suitability of the MVs for applications.     

Viscosities of Binary and Ternary Mixtures of Water,Alcohol, Acetone,and Hexane

This articles studied and determined the viscosities of the binary mixtures of water–methanol, water–ethanol, water–propanol, water–acetone, acetone–ethanol, methanol–ethanol, and acetone–hexane and the ternary mixtures of water–methanol–ethanol and water–ethanol–acetone at 20°C. It is shown that the mixing of water with the alcohols and acetone resulted in a positive deviation of viscosity, which reached the maximum value at the water mole fraction x ₁ ～ 0.7 for water–methanol, x ₁ ～ 0.72 for water–ethanol, x ₁ ～ 0.74 for water–propanol, and x ₁ ～ 0.83 for water–acetone binary mixture. This viscosity deviation can be mainly attributed to the formation of micelles of alcohol or acetone molecules in water because of the hydrophobic attraction between the hydrocarbon chains. The micelle surfaces are surrounded by hydration layers, leading to the positive viscosity deviation in the liquid mixtures because the water in hydration layers has a much higher viscosity than bulk water. Also, the contrary observation was found in the binary mixtures of acetone–ethanol and acetone–hexane, having a negative viscosity deviation.     

Extraction Separation of BSA in Aqueous Two-Phase Systems of Anionic and Cationic Surfactant Mixtures

Aqueous two-phase systems (ATPS) are formed in mixtures of sodium dodecylsulfate (SDS), cetyltrimethyl ammonium bromide (CTAB), and sodium bromide (NaBr). Two different kinds of ATPS appear when CTAB and SDS surfactants are in excess, respectively. Such ATPS may provide a new, useful partitioning system for separation of bovine serum albumin (BSA). The partitioning of BSA was studied in these systems. The results show that the partitioning is affected by the electrical property, the hydrophobicity and the structure of liquid crystal (LC), which exists in the top phase of the ATPS. BSA is extracted into the top phase with higher distribution coefficient when LC and BSA are oppositely charged. The hydrophobicity of LC, which can be improved by increasing the length of alkyl group, enhances the distribution coefficient. The hydrophobicity of lamellar LC and hexagonal LC is stronger than that of cubic LC, which causes extractive capability of the former is higher than the latter.