Silica-metalloporphyrins hybrid materials: preparation and catalysis to hydroxylate cyclohexane with molecular oxygen

Three types of novel silica-metalloporphyrins hybrid materials, Si-S-APTCPPFe, Si-S-APTCPPMn and Si-S-APTCPPCo, were prepared at room temperature by sol–gel method involving a thiol-ene polymerization reaction of 5-(4-allyloxy)phenyl-10,15,20-tri(4-chlorophenyl)porphyrin (APTCPP) with 3-mercaptopropyltrimethoxysilane (MPS). The hybrid materials were characterized by XRD, SEM, FT–IR, UV–Vis and TG, and were investigated as catalysts for the aerobic oxidation of cyclohexane. It is found that these hybrid materials are more efficient catalysts than the analogous non-supported metalloporphyrins for cyclohexane hydroxylation in metalloporphyrin–O₂–ascrobate system and the metal ion in the porphyrins significantly affected the catalytic efficiencies of these hybrid materials.     

Synthesis,characterization and visible-light photocatalytic activity of TiO2–SiO2 composite modified with zinc porphyrins

Three types of silica gel supported titanium dioxide particles immobilizing Zn(II) carboxylphenyl porphyrins appending p-CH₃, p-H and p-Cl phenyl substituents (designated as ZnMP–TiO₂–SiO₂, ZnPP–TiO₂–SiO₂ and ZnCP–TiO₂–SiO₂, respectively) have been synthesized and characterized using SEM, XRD, IR, AFS, DRS, UV–Vis, XPS and TG. The photodegradation of α-terpinene in aqueous suspension was used to determine the photocatalytic activity of TiO₂–SiO₂ samples which had been impregnated with Zn(II) porphyrins, as sensitizers. The experimental results confirmed that the photocatalytic activitys of these composites are much higher than those of the nonmodified TiO₂–SiO₂ under visible light irradiation and follow the order of ZnMP–TiO₂–SiO₂ > ZnPP–TiO₂–SiO₂ > ZnCP–TiO₂–SiO₂.     

Styrene-hydroxyethyl methacrylate copolymer-supported porphyrinatomanganese(III) complexes: synthesis and catalytic cyclohexane hydroxylation with molecular oxygen

Two new styrene-hydroxyethyl methacrylate copolymers containing immobilized porphyrinatomanganese(III) were prepared and characterized as microspheres by SEM, UV–Vis, FT-IR, and TG-DTG. Their catalytic activities have been investigated for the hydroxylation of cyclohexane in the presence of molecular oxygen under mild conditions. The copolymer microspheres proved to be more efficient catalysts than the corresponding non-supported porphyrinatomanganese(III) complex. The alkylated polymer microspheres with porphyrinatomanganese(III) had the highest catalytic activity, which may be attributable to the hydrophobic microenvironment around the porphyrinatomanganese(III) centers, resulting from the alkyl groups.     

Fabrication of porous graphitic carbon nitride-titanium dioxide heterojunctions with enhanced photo-energy conversion activity

Porous graphite-phase polymeric carbon nitride (GPPCN)/TiO₂ donor-acceptor heterojunction was facilely fabricated through the combination of a template technique with a co-calcination process, which exhibited much higher photoelectric activity compared to pristine carbon nitride and TiO₂. The precursor of porous GPPCN (pGPPCN), porous melem, was prepared by using a green template, calcium carbonate, which could be easily removed by diluted hydrochloride. The pGPPCN/TiO₂ heterojunction was then obtained by the assembly and subsequent co-calcination of TiO₂ nanoparticles with porous melem. The formation of pGPPCN/TiO₂ donor-acceptor heterojunction prepared by this method showed improved surface area and light absorption. Moreover, the composite presented much higher photo-energy conversion activity than those of GPPCN, pGPPCN and TiO₂, which could be mainly ascribed to the high charge carrier separation efficiency. This study provides a new approach for the design and development of various photocatalysts with high efficiency for applications in energy fields.     

不同形貌的金字塔结构对硅片表面钝化和异质结太阳电池的影响

在晶体硅表面沉积本征非晶硅层的异质结（SHJ）太阳电池以其高效率、高稳定性、低成本和低温制备等诸多优势被人们广泛关注. 在晶体硅衬底表面制绒,是提高太阳电池效率的有效途径之一. 本文采用四甲基氢氧化铵（TMAH）在硅片表面制备了不同形貌的金字塔结构的硅异质结电池衬底,并应用到电池中. 通过研究不同金字塔的形貌,光学特性以及电学特性,找出提高硅片钝化效果,改善异质结电池的性能的优化的金字塔结构. 结果表明：2%（w）TMAH,10%（w）异丙醇（IPA）可以在硅片表面制得标准四面体金字塔结构. 和其它两种金字塔结构相比较,标准四面体金字塔结构绒面衬底反射率最低,可以提高太阳电池的短路电流密度（J_sc）. 同时,这种结构金字塔形貌可以提高钝化效果,改善电池各项性能参数.     

Novel Carboxymethyl Chitosan Microspheres for Controlled Delivery of Chelerythrine

Novel carboxymethyl chitosan (O-CMCS) microspheres containing an anti-tumor drug chelerythrine (CHE) have been successfully prepared by an emulsion crosslinking method using glutaraldehyde. The optimized microsphere formulation was characterized for particle size, shape, morphology, crystallinity and in vitro drug release. Results for mean particle size, drug loading content, entrapment efficiency and in vitro drug release of chelerythrine loaded microspheres were found to be 12.18 μm, 4.08%, 54.78% and 35.30% at pH 7.4 in 20 h, respectively. The optimized microspheres had an imperfect crystalline lattice and a spherical, rough morphology and the CHE release from O-CMCS microspheres followed the Higuchi matrix model. All these results suggested that O-CMCS microspheres are a promising carrier system for controlled drug delivery.     

不同形貌的金字塔结构对硅片表面钝化和异质结太阳电池的影响

在晶体硅表面沉积本征非晶硅层的异质结(SHJ)太阳电池以其高效率、高稳定性、低成本和低温制备等诸多优势被人们广泛关注.在晶体硅衬底表面制绒,是提高太阳电池效率的有效途径之一.本文采用四甲基氢氧化铵(TMAH)在硅片表面制备了不同形貌的金字塔结构的硅异质结电池衬底,并应用到电池中.通过研究不同金字塔的形貌,光学特性以及电学特性,找出提高硅片钝化效果,改善异质结电池的性能的优化的金字塔结构.结果表明:2%(w)TMAH,10%(w)异丙醇(IPA)可以在硅片表面制得标准四面体金字塔结构.和其它两种金字塔结构相比较,标准四面体金字塔结构绒面衬底反射率最低,可以提高太阳电池的短路电流密度(Jsc).同时,这种结构金字塔形貌可以提高钝化效果,改善电池各项性能参数.     

Study on Vulcanization and Thermal Decomposition Behaviors of Methyl Vinyl Silicone Rubber/Polyurethane Rubber Blends

The vulcanizing properties and thermal decomposition of methyl vinyl silicone rubber/ polyurethane rubber blends were studied. The results of vulcanization show that with the addition of polyurethane rubber, the viscosity, cross-linking density, activation energy and vulcanization rate of the blends decreased while the scorch behavior was not significantly changed. For the decomposition behavior, the maximum thermal decomposition rate of the blends was increased with increasing content of polyurethane rubber; however, the thermal stability of the blends was decreased. Analysis of the thermal decomposition kinetics shows that the activation energy of the blends gradually decreased.     

乙二醛缩双(邻氨基苯酚)合锰(II)配合物的合成及其催化行为研究

合成了乙二醛缩双(邻氨基苯酚)合锰(II)配合物, 讨论了其在DMF中的载氧行为、氧合动力学; 设计正交试验考察了以分子氧为氧源, 该配合物催化氧化醋酸去氢表雄酮生成7-酮基醋酸去氢表雄酮的性能, 最高收率达78.4%.     

麦斛细胞毒活性成分研究

利用硅胶、聚酰胺柱层析等分离方法, 从麦斛全草的乙醚萃取物中分离得到4个化合物, 经化学方法和光谱分析(UV, IR, NMR, MS)鉴定为3,4,7-三羟基-2-甲氧基菲(1), 2,5-二羟基-4-甲氧基菲(2), eugenitin (3)和2,5-二羟基-4-甲氧基-9,10-二氢菲(4), 其中1为新化合物. 采用MTT法分别测得化合物1和2对体外培养的人急性髓性白血病细胞和人肝癌细胞增殖的抑制活性, 并分别考察了增敏剂葛根素对化合物1和2增殖活性的协同作用.