Advanced Materials Research Vol. 1094

Abstract: The enantiomer isomeric nucleosides of 1,3-bis (1'-deoxy-β-ribofuranose-2'-yl)-thymine were synthesized from 1-deoxy-5-O-triphenylmethyl-ribose in high yield and selectivity. The key step is the coupling of 1-deoxy-5-O-triphenylmethyl-2,3-O-cyclosulphate-ribose and thymine using cesium carbonate as the base.

Abstract: A series of flavone derivatives conjugated with carbohydrate were synthesized from 2-(3,4-dimethoxyphenyl)-4H-chromen-4-one. The key step is its cross coupling with the carbohydrate under Sonogashira reaction.

Abstract: The main object of the present invention is to provide an improved process for the preparation of Iloperidone, which would be more simple, economical and easy to implement on large scale preparation. In this paper, 1,3-difluorobenzene and 1-(4-hydroxy-3-methoxyphenyl) ethanone are starting materials. And then tartaric acid is added. The key intermediate (Z)-4-(2,4-difluorobenzoyl) piperidine oxime is obtained through stereoselectivity. With the key intermediate and 1-(4-(3-chloropropoxy)-3-methoxyphenyl) ethanone, the target product is obtained directly under the condition of catalyst.

Abstract: The sulfur-free exfoliated graphite(EG) was prepared by chemical oxidation method using the mixture of HClO4 and CH3COOH as reaction medium, the 100 orders natural flake graphite(NG) as raw material, and KMnO4 as oxidant. The effects of influence factors on the exfoliation volume(EV) were analyzed by single factor experiments and orthogonal experiments, the structure of NG and EG were characterized by X-ray diffraction. Results show that the optimum preparation conditions were as follows: graphite(g): KMnO4(g): the mixed acid (mL) = 1:0.35:4, HClO4 (mL):CH3COOH (mL) = 3:1, reaction temperature at 35°C for 90 minutes, the maximum EV of up to 500mL/g. The influence factors are governed the descending order: the volume ratio of HClO4 :CH3COOH, reaction temperature, the dosage of mixed acid, the dosage of KMnO4, reaction time.

Abstract: Objective To obtain immobilized nanomaterials with good performance, the preparation condition of chitosan nanospheres by miniemulsion crosslinking method was optimized. Methods The chitosan nanospheres were synthesized by miniemulsion crosslinking method with Span80 and Tween80 as the emulsifier, glutaraldehyde as the crosslinker, n-hexane and paraffin liquid as oil phase,chitosan acetic acid solution as aqueous phase. The particle size was measured by Zetasizer nanoanalyzer. Results The results of the univariate tests show that the optimal preparation condition of chitosan nanospheres can be obtained when water/oil volume ratio is 3:2. The size distribution of chitosan nanospheres is 18.17nm to 190.1nm. Conclusion The chitosan nanospheres by miniemulsion crosslinking method are suitable materials as enzymes and proteins immobilized carrier.

Abstract: The electronic structure and photoinduced surface/interface charge transfer processes have been studied in poly [2-methoxy-5-(28-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) thin films spin-coated on Au using Kelvin Probe Force Microscopy. The results show that the MEH-PPV film,dissolved at about 1% weight/volume in Chloroform (CHCl3), is a n-type semiconductor with an optical band gap of around 2.1 eV and a surface work function of 4.6 eV. MEH-PPV was also dissolved in chlorobenzene (CB) with the same concentration as the CHCl3 solution, is a p-type semiconductor with an optical band gap of around 2.1 eV and a surface work function of 4.75 eV, and its photovoltaic response is dominated by its free surface rather than the interface with the substrate.

Abstract: Amorphous silica gel was modified by titania via an impregnation-surface hydrolysis approach and used as the support for preparing gold catalysts through an direct anion exchange method. These supported gold catalysts were characterized by XRD and TEM, and applied for the catalytic cyclopentane oxidation to cyclopentanone using oxygen in the absence of any solvent and initiator. The catalyst with a loading of 0.1wt.% gold and 10wt.% TiO₂ exhibited 7.2% cyclopentane conversion and 77.4% selectivities (including cyclopentanone and cyclopentanol) under the reaction conditions of 145°C, 2.0 MPa and 3 h. All the gold catalysts studied are very active in selective cyclopentane oxidation, and their high activities can be attributed to well dispersion and nanometer effect of gold particles within the catalysts.

Abstract: In this paper, the pelletizing as carbonaceous reducing agent of industrial silicon were prepared using anthracite fine, petroleum coke powders, charcoal powders and silica fume as materials, and starch D as binder, the effects of different wetting agents on performances such as compressive strength of fresh pelletizing and dry pelletizing, the heat intensity and the shatter strength were researched. The results show that: when starch D mass content was 3.04% and sodium hydroxide solution was used as wetting agent, the performances were better, and compressive strength of fresh pelletizing was 1401.1N, compressive strength of dry pelletizing was 8109.3N, the heat intensity was 95.34%, and the shatter strength was 99.09%.

Abstract: Fe-TiO₂ loaded on activated carbon fiber felts (ACFF) composite photocatalysts were prepared by dipping ACFF in the Fe-TiO₂ sol using tetrabutyl titanate (TBT) as precursors and FeCl₃•6H₂O as dopant, followed by calcination at 500 °C in N₂ atmosphere. The composites were characterized by XRD, UV-vis absorbance spectra, SEM and BET. The photocatalytic activities under visible-light irradiation were investigated by the degradation of methyl orange (MO). The results showed that the absorption wavelengths of Fe-TiO₂ composites were extended to 610 nm, the absorption edge had a pronounced ‘red shift’. Fe-TiO₂ nanoparticles were evenly loaded on the surface of ACFs. Because of the synergy action of adsorption and photocatalysis, the degradation rate of MO with Fe-TiO₂/ACFs was about 20% higher than that of ACFs, when irradiated for 180 min under visile-light.

Abstract:

Skim natural rubber (NR-s) is solidified by skim natural rubber latex. NR-s is often evaluated to low grade natural rubber because of its many bad properties such as poor resistance to aging. In order to improve the NR-s comprehensive property, fluorinated groups were incorporated into NR-s molecular chain by grafting via solution polymerization method. The grafted copolymer was characterized and the effects of conditions on grafting ratio and grafting efficiency were investigated. The thermal stability are also examined.