生物模板法合成纳米磷酸钛粉体的制备及表征

大部分生物模板具有廉价易得、环保无毒等优点,分别使用茶碱及废酵母模板仿生合成层状及层状孔状复合纳米结构磷酸钛粉体,并通过900℃高温煅烧得到结晶良好的TiP2O7晶体。茶碱与废酵母细胞同时可作为表面活性剂,其内部及表面区域限制了无机成核的位置和空间,相当于纳米尺寸的反应器。     

Synthesis and NMR Characterization of Titanium and Zirconium Oxides Incorporated in SBA-15

Single oxides of Ti and Zr incorporated SBA-15 were prepared and characterized by N₂ adsorption, NMR, and XPS techniques. ²⁹Si MAS NMR results suggest the formation of Si–O–X linkages (X: Ti or Zr) by an increase in the ratio of Q ³/Q ⁴ in the presence of Ti or Zr. XPS analysis of Ti–SBA-15 catalysts indicate the presence of Ti–O–Si bonds in addition to Ti–O–Ti and Si–O–Si bonds, supporting the NMR evidence.     

Superhydrophobic Coating Polymer/Silica Nanocomposites: Part I Synthesis and Characterization as Eco-Friendly Coating

Silicon - Special coatings with desirable properties like superhydrophobicity, play an essential role in development of coated substrate surfaces. Solar cells, outdoor items and packaging materials...     

炭黑负载铂纳米颗粒的制备与表征

在不加保护剂的情况下,采用微波法合成了金属铂纳米颗粒,并负载到XC-72导电炭黑上.TEM结果显示,合成的未负载的铂纳米颗粒粒径小、粒径分布范围窄,平均粒径为2.5 nm,粒径分布的相对标准偏差为0.216.炭黑负载的铂纳米颗粒粒径与未负载时相当,且同期负载时,负载的铂纳米颗粒数量较多,负载效果好;而非同期负载时,负载的铂纳米颗粒数量少.     

Plasma-Sprayed Aluminum and Titanium Adherends: I. Characterization of Coatings

The morphological and surface chemical properties of plasma-sprayed coatings on metals have been investigated using surface characterization techniques. Organic polymeric and inorganic powders were plasma-sprayed on aluminum and titanium. Organic-polymeric coatings were prepared using epoxy, polyester, polyimide, and cyanate ester components. Inorganic coatings were obtained by plasma-spraying Al₂O₃, AlPO₄, MgO, and SiO₂ on aluminum adherends, and TiO₂, TiSi₂, MgO, and SiO₂ on titanium adherends. The organic-polymeric coatings were prepared at one thickness while the inorganic coatings were sprayed to obtain two different thicknesses. SEM photographs reveal various morphological differences in the sprayed specimens. The surface morphology ranged from smooth to nodular among the plasma-sprayed specimens. Surface chemical analysis of the plasma-sprayed coatings indicated that little or no chemical degradation of the components occurred as a result of plasma-spraying. However, plasma-sprayed TiSi₂ appeared to be a mixture of silica and a titanium silicate.     

Plasma-Sprayed Aluminum and Titanium Adherends: I. Characterization of Coatings

The morphological and surface chemical properties of plasma-sprayed coatings on metals have been investigated using surface characterization techniques. Organic polymeric and inorganic powders were plasma-sprayed on aluminum and titanium. Organic-polymeric coatings were prepared using epoxy, polyester, polyimide, and cyanate ester components. Inorganic coatings were obtained by plasma-spraying Al₂O₃, AlPO₄, MgO, and SiO₂ on aluminum adherends, and TiO₂, TiSi₂, MgO, and SiO₂ on titanium adherends. The organic-polymeric coatings were prepared at one thickness while the inorganic coatings were sprayed to obtain two different thicknesses. SEM photographs reveal various morphological differences in the sprayed specimens. The surface morphology ranged from smooth to nodular among the plasma-sprayed specimens. Surface chemical analysis of the plasma-sprayed coatings indicated that little or no chemical degradation of the components occurred as a result of plasma-spraying. However, plasma-sprayed TiSi₂ appeared to be a mixture of silica and a titanium silicate.     

A Novel Catalyst Type Containing Noble Metal Nanoparticles Supported on Mesoporous Carbon: Synthesis,Characterization and Catalytic Properties

We report on a method for the controlled synthesis of a new type of high specific surface area mesoporous carbons denoted as the CMH family. By using mixtures of colloidal silica particles as templates it was possible to synthesize samples exhibiting 1,630 m² g⁻¹ specific surface area and 4.37 cm³ g⁻¹ pore volume. CMH materials exhibit high thermal stability in oxygen and can be used as catalyst supports. This function was demonstrated by synthesizing Pt/CMH and Rh/CMH catalysts and testing them in the hydrogenation of cyclohexene. We have found Pt/CMH to be more stable and easier to regenerate than Rh/CMH.     

Silica‐Supported Zirconium Complexes and their Polyoligosilsesquioxane Analogues in the Transesterification of Acrylates: Part 1. Synthesis and Characterization

Various silica‐supported acetylacetonate and alkoxy zirconium(IV) complexes have been prepared and characterized by quantitative chemical measurements of the surface reaction products, quantitative surface microanalysis of the surface complexes, in situ infrared spectroscopy, CP‐MAS ¹³C NMR spectroscopy and EXAFS. The complex (SiO)Zr(acac)₃ (acac=acetylacetonate ligand) ( 1 ) can be obtained by reaction of zirconium tetraacetylacetonate [Zr(acac)₄] with a silica surface previously dehydroxylated at 500 °C. The complexes (SiO)₃Zr(acac) ( 2 ) and (SiO)₃Zr(O‐n‐Bu) (n‐Bu=butyl ligand) ( 3 ) can be synthesized by reaction of (SiO)₃Zr H with, respectively, acetylacetone and n‐butanol at room temperature. The spectroscopic data, including EXAFS spectroscopy, confirm that in compound 1 the zirconium is linked to the surface by only one Si O Zr bond whereas in the case of compounds 2 and 3 the zirconium is linked to 3 surface oxygen atoms which are sigma bonded. EXAFS data indicate also that the acetylacetonate ligands behave as chelating ligands leading to a hepta‐coordination around the zirconium atom in 1 and a penta‐coordination in 2 . In order to provide a molecular analogue of 1 , the synthesis of the following polyoligosilsesquioxane derivative (c‐C₅H₉)₇Si₈O₁₂(CH₃)₂Zr(acac)₃ ( 1′ ) was achieved. The compound 1′ is obtained by reacting (c‐C₅H₉)₇Si₈O₁₁(CH₃)₂(OH), 4 , with an equimolecular amount of Zr(acac)₄. In the same manner, syntheses of complexes (c‐C₅H₉)₇Si₇O₁₂Zr(acac) ( 2′ ) and of (c‐C₅H₉)₇Si₇O₁₂Zr(O‐n‐Bu) ( 3′ ) were achieved by reaction of the unmodified trisilanol, (c‐C₅H₉)₇Si₇O₉(OH)₃, with respectively Zr(acac)₄ and Zr(O‐n‐Bu)₄ at 60 °C in tetrahydrofuran. Compounds 1′ , 2′ and 3′ can be considered as good models of 1 , 2 and 3 since their spectroscopic properties are comparable with those of the surface complexes. The synthetic results obtained will permit us to study the catalytic properties of these surface complexes and of their molecular analogues with the ultimate goal of delineating clear structure‐activity relationships.     

Electron Transfer Kinetics on Boron-Doped Diamond Part I: Influence of Anodic Treatment

Boron-doped diamond electrodes, both as-grown and polarized anodically under different conditions, were prepared in order to study the chemical and electrochemical changes of diamond and clarify the role played by the surface-state density. Many different treatments were employed: as-grown (BDD_ag), mildly polarized (BDD_mild), strongly polarized in perchloric acid (BDD_severerpar;, and strongly polarized in a sulphuric acid-acetic acid mixture (BDD_AcOHrpar;. Charge transfer processes at the electrode surface were studied by cyclic voltammetry. Simple electron transfer processes such as the outer-sphere redox system ferri/ferrocyanide (Fe^III/II;(CN)₆rpar; and complex charge transfer reactions such as the inner-sphere 1,4-benzoquinone/hydroquinone (Q/H₂Q) redox reaction were chosen to test the electrochemical properties of the electrodes. The properties of the diamond electrodes were found to undergo strong modification as a function of surface treatment. The active surface area and the reaction rate constants decreased significantly upon anodic polarization. Important drops in the charge carrier concentration on the surface and in true surface area led to hindrance of electron transfer at the electrode.     

碳纳米管负载铂-二氧化钌纳米颗粒催化剂的制备及表征

以多壁碳纳米管(MWNTs)为载体,采用化学还原法制备了多壁碳纳米管负载的铂-二氧化钌纳米颗粒催化剂(Pt-RuO2/MWNTs),并利用透射电镜(TEM)、电化学法等技术对该催化剂形貌和电化学性质进行了表征。结果表明,大小约为4～5nm的金属纳米颗粒均匀地分散在碳纳米管上,同时考察了该催化剂在铁氰化钾溶液中的循环伏安行为以及对该催化剂进行了电化学阻抗分析。     

Alkali Dinitramide Salts. Part 1: Synthesis and Characterization

Starting from commercially available ammonium dinitramide (ADN), which was dissolved either in water or in methanol, the sodium, potassium, rubidium and cesium dinitramide were synthesized in yields >70% by adding the corresponding alkali metal hydroxide. The basic equation for the reaction is the following:     

以多孔金属钛片为载体的SiO2膜的制备和表征

采用溶胶－凝胶法，用正硅酸乙酯为原料，以多孔金属钛片为载体，制备了担载型多孔ＳｉＯ２复合膜。探讨了制备过程参数对膜性能的影响。建立了基于Ｋｅｌｖｉｎ方程，以流动法测定了无机微孔膜的活性孔径分布的装置，检测了膜的活性孔孔径分布。     

等离子体法制备碳纳米管负载银粒子及抑菌性研究

通过温和的等离子体法制备出碳纳米管负载纳米银粒子,并研究了其对大肠杆菌的抑制作用。首先用氧等离子体处理碳纳米管,再将银离子负载在碳纳米管表面上,接着用氢等离子体将负载的银离子还原成纳米银粒子。用TEM和XRD对制备出的银粒子进行表征,研究表明,平均粒径为5nm左右的银粒子负载在碳纳米管表面。对大肠杆菌的抑菌实验表明,Ag-CNTs浓度大于1μg/mL时,对大肠杆菌生长抑制效果明显。     

水溶液中硒化物纳米颗粒的制备与表征

以醋酸铅和氯化镉作为铅源和镉源,自制的Na2SeSO3溶液为硒源,可溶性淀粉为表面活性剂,常温常压下,在水溶液中合成了PbSe和CdSe纳米颗粒.讨论了淀粉溶液浓度、pH值和反应时间等制备工艺参数对硒化物纳米颗粒的生成和颗粒尺寸的影响.用X射线粉末衍射、紫外-可见吸收光谱、Raman光谱与透射电子显微镜等测试手段对所得...     

Preferential Oxidation of CO in H2-Rich Gas at Low Temperatures over Au Nanoparticles Supported on Metal Oxides

We investigated Au catalysts supported on TiO₂, Fe₂O₃, and ZnO for their preferential oxidation of CO in a H₂-rich atmosphere. Both full conversion and selectivity were achieved over Au/Fe₂O₃ and Au/ZnO around room temperature, but at higher temperatures the CO conversion was suppressed due to competition between CO and H₂.     

微乳液中纳米ZnS、CdS微粒的合成与表征

以乙酸锌、硝酸镉和硫化钠为原料,室温下,采用微乳液法合成ZnS、CdS纳米粒子。利用rIEM、XRD、Raman、UV-Vis和PL等检测手段对产物进行表征。结果表明,合成的zns纳米晶粒径在25m左右,为立方β-Zns晶相;ω值对合成纳米cds的形貌和粒径产生重要影响,纳米Cds粒径为5nm左右,在紫外吸收光谱和荧光发射光谱上均表现出明显的特征,可作为荧光量子点使用。     

碳负载型IrO2水合物复合电极材料的制备及电容性能研究

文章以KB600型活性炭和少量氯铱酸为原料,分别采用共沉积法和还原氧化法制备了碳载氧化铱电极材料,通过循环伏安测试和恒流充放电测试对比分析了材料的电化学性能。其中,还原氧化法制备的碳载IrO2电极材料的比电容量高达389.7 F·g-1,具有较好的应用前景。     

介孔分子筛固载Keggin结构钼钨磷杂多酸的制备及表征

用萃取法合成了两种 Keggin结构的钼钨磷杂多酸 ,用水热法制取了 AIMCM- 41介孔分子筛 ,经离子交换制成 HAIMCM- 41 ;浸渍法制取固载型 HPA/ HAIMCM- 41催化剂。用 IR、XRD对其结构和性能进行了表征。结果表明合成的 HPA具有典型的 Keggin结构而 HAIMCM- 41具有典型的介孔性质 ,固载后 HPA的 Keggin结构基本保持