添加吐温40合成钛硅分子筛TS-1

 以自制的四丙基氢氧化铵（TPAOH）水溶液为模板剂,采用在水热晶化合成体系中添加少量非离子表面活性剂——吐温40的方法,合成了钛硅分子筛TS-1,可以明显减少TPAOH的用量,而且在一天之内,即可得到纳米尺寸的TS-1。运用XRD、TEM、BET、FT-IR及UV-Vis等表征手段考察了TS-1的结构及物理性能,并以丙烯环氧化为探针反应,考察其催化性能,得到的结果表明,用这种方法合成的TS-1样品具有较高的结晶度和较大的比表面积,晶貌呈均匀的立方体状,颗粒尺寸在100 nm左右,并且样品中含有极少量锐钛矿型TiO2,其催化丙烯环氧化反应性能较好。     

均相水解法制备金红石含量可控的纳米TiO2

用均相水解法通过调节对甲苯磺酸的添加量制备了金红石含量线性可控的纳米TiO2粒子,相同条件下,没有加入对甲苯磺酸时,制备的TiO02颗粒为纯锐钛矿晶型．制备的纳米TiO2颗粒,其单晶尺寸为19．5mm(金红石),13．5mm(锐钛矿),比表面积72．7m^2／g,通过公式计算得到了制备的TiO2纳米颗粒带隙能为2．83eV,比P25和纯锐钛矿纳米TiO2颗粒的带隙能均低．     

介孔二氧化钛的非有机模板剂法合成

 采用硫酸钛水解法在不使用有机模板剂的条件下合成了高热稳定的锐钛矿型介孔TiO2. 以工业硫酸钛溶液为原料,经两步水解得到介孔结构的偏钛酸, 500 ℃下焙烧后得到比表面积为202.2 m2/g、 平均孔径为2.8 nm并具有超强酸特性的介孔TiO2. 使用X射线衍射、 N2吸附、扫描电镜、 X射线能谱和红外光谱对该样品进行了表征,初步讨论了介孔的形成机理. 吸附在偏钛酸孔壁上的硫酸分子和孔壁上的自由羟基键合,起到了孔结构的导向作用及支撑作用.     

Lipid Peroxidation Processes Photoinduced by Titanium Dioxide in Emulsion Systems,Representative of Sunscreen Formulations

This article studies the peroxidation of linoleic acid and of porcine skin lipids on ultraviolet B (UVB) irradiation, in the presence of various TiO₂ specimens used as inorganic sunscreen pigments in different emulsion systems. It was found that different TiO₂ specimens induce quite variable lipid peroxidation in the same emulsion system, which suggests that the different coatings widely differ in their effectiveness to lower the photocatalytic activity of TiO₂. However, it was also found that the extent of lipid peroxidation caused by the same TiO₂ pigment in different emulsions was even more variable than the effects of different pigments in the same system. This finding might imply that the choice of the formulation components different from TiO₂ could be of paramount importance as far as the potential skin damage induced by the photocatalytic activity of TiO₂ is concerned.     

微乳液和均匀沉淀耦合法制备CeO2纳米粒子

用W/O微乳液和草酸二甲酯均匀沉淀耦合法制备出单分散性好并具有较窄粒度分布的CeO2纳米粒子,测试了其形貌、粒径及粒径分布和晶体结构等特征.实验结果表明,表面活性剂的种类和反应物的相对初始浓度对产物平均粒径具有规律性的影响;随着焙烧温度升高,产物的平均粒径明显增大.     

液相沉淀法制备稀土-锆固溶体及其性能研究

采用液相沉淀法制备了Ce0.6Zr0.3La0.05Y0.05O2固溶体。通过BET,XRD,SEM,程序升温还原和氧脉冲吸附等方法对合成产品性能进行了表征。研究了前驱体的形态、高温水热处理、表面处理以及后期固溶体的还原处理对固溶体性能的影响。其中前驱体的高温水热处理和固溶体的还原处理对固溶体的催化性能有很大的影响。200℃水热处理制得的固溶体经1000℃老化4 h后,比表面积为25.3 m2.g-1,孔容为0.21 cm3.g-1,经800℃还原处理3 h后储氧量为478.3μmol.g-1,显示了较高的比表面积和储氧能力的高温稳定性。     

纳米二氧化钛粉末的溶胶-凝胶法合成及晶相转化

Nanosized TiO₂ powder with anatase and rutile structures was synthesized by a sol-gel method using TiCl₄ ethanol solution as a precursor.The grain size of TiO₂ powder was about 63nm after the precursor was calcined at 600℃ for 2 hours .The experimental techniques of XRD,TEM and Particle Distribution were used to characterize the synthesized specimens. Various special effects were investigated for their contribution to crystal structure and the size of TiO₂ powder .The formation of anatase as well as the rutile phase of TiO₂ was indicted from the XRD when the reaction temperature was above 30℃ and when the sol was irradiated by infrared rays .However, an anatase TiO₂ powder formed after the heat treatment of the dried gel in a temperature range from 300℃ to 500℃.Under the vacuum drying and with the calcined time below 3hours ,the anatase phase was gained .As well as with the increase of gelatinizing time, the anatase TiO₂ powder was obtained.     

葡萄糖还原氢氧化铜制备球形氧化亚铜及其粒度控制研究

以Cu(OH)2为前躯体,用葡萄糖还原制备了不同粒径的单分散球形氧化亚铜粉末。利用扫描电镜和smileview软件对Cu2O粉末进行了表征分析,并通过上述分析考察了反应温度和反应物浓度等因素对Cu2O粉末粒径的影响。结果表明,随着反应温度与葡萄糖投加浓度的提高,颗粒粒径减小;而随着氢氧化钠投加浓度的提高,颗粒粒径增大;体系内最终颗粒密度n+∞或颗粒个数n与各影响因素的变化呈直线关系。最后根据晶体成核生长模型初步分析了反应条件对Cu2O颗粒粒径的影响机理。     

利用室温固态反应制备球霰石型CaCO3粒子

合成形态、大小及结构可人为调控的无机材料是现代材料科学的重要研究方向[1]. 借助于各类有机添加剂及模板剂的调控作用, 可利用溶液合成方法制备出形貌与结构受到有效调控的无机粒子[2,3]. 室温固态化学反应已被成功地应用于多种无机纳米粒子[4]及纳米线[5]的合成, 并显示出高效、节能、无污染和操作简便等优点, 因而在材料合成领域具有应用前景[6].     

Study of the Adsorption of Dicarboxylic Acids on Titanium Dioxide in Aqueous Solution

The photodegradation processes using semi-conductor like TiO₂ as a catalyst, provide new methods for waste water treatment. In this method the step of adsorption of organic compounds on the semi-conductor surface could have a prominent influence. In this work we describe the results of the study of the dicarboxylic acids adsorption on TiO₂ (P25) in aqueous phase. The Langmuir model gives a good representation of the adsorption of the studied organic diacids. The maximum adsorption capacities are close to 7.10^–5 mol/g for the four studied diacids. The diffuse reflectance infrared spectroscopy (IRFT-DRIFT mode) of loaded TiO₂ enables to demonstrate the formation of a dicarboxylate film on the semi-conductor surface.     

Interrelationship of Structural-Adsorption Characteristics of Titanium Dioxide and Its Photocatalytic Activity in the Gas-Phase Oxidation of Acetone and Ethanol

X-ray phase analysis and adsorption techniques were used to study the effect of heat treatment of starting amorphous titanium dioxide on its structural-adsorption characteristics, which determine the photocatalytic activity in the gas-phase oxidation of acetone and ethanol. In addition to the specific photocatalytic activity of the samples due to the amount of the active anatase TiO₂ modification, the adsorption capacity of the photocatalysts, which is a function of the specific surface and pore adsorption volume, affects the rate of the reactions studied.     

水溶液中丙酮的敏化室温磷光测定

测定水溶液中微量丙酮,常用吸光光度法^[1～3]和色谱法^[4,5]等,这些方法固然灵敏度较高,但样品的预处理比较复杂,分析速度慢,线性范围窄.本文以丁二酮为能量受体,建立了水溶液中微量丙酮的敏化室温磷光测定法.方法简便快速,重现性好,灵敏度亦高.     

Synthesis of Nanoscale Shell-core Titania Coated Silica Particles in the Presence of Polyether Polyamine and the Phase Transition

IntroductionTitanium dioxide with the rutile or the anatasestructure as,in principle,a white pigmentis widelyused as paints and plastic additives because of itshigh refractive index,oil adsorption,chemical orthermal stability[1— 4 ] .The most common manu- fac-ture of this material is based on the digestion of theore ilmenite(Fe O· Ti O) with sulfuric acid,fol-lowed by hydrolyzing the solution of titanium ionsand the calcination of the hydrous titanium ox-ides[5] .Another industrial prepara…     

The Formation and Structural and Phase Transformations of Aluminum Hydroxy Species in Hydrothermal Synthesis under Conditions of Homogeneous Precipitation from Sulfate Solution

By X-ray powder diffraction analysis, Raman spectroscopy, scanning and transmission electron microscopy, and low-temperature nitrogen adsorption method, it was studied how the temperature of hydrothermal synthesis affects the phase composition of precursor species and the structure and morphology of alumina obtained under conditions of low-temperature hydrothermal synthesis at 90–130°C in the system 0.5Al₂(SO₄)₃ · 18H₂O∥0.2C₁₆H₃₃(CH₃)₃NBr∥5i-PrOH∥85H₂O∥2CO(NH₂)₂. It was found that, at T_HTS = 90–110°C, alumina microspheres with globular structure form from X-ray amorphous hydrated alumina with an admixture of NH₄Al₃(SO₄)₂(OH)₆. It was shown that needle-like alumina particles with slitlike pores form from NH₄Al(OH)₂CO₃ obtained at T_HTS = 110–120°C. At T_HTS = 130°C, under conditions of the formation of γ-AlOOH, alumina spherulites constituted by needle-like particles with block–layer structure form. It was determined that the temperature range of the formation of metastable crystalline modifications of alumina is controlled by the phase composition of hydrothermal synthesis products.     

Photocatalytic Effects of Rutile Phase TiO2 Ultrafine Powder with High Specific Surface Area Obtained by a Homogeneous Precipitation Process at Low Temperatures

The photocatalytic characteristics of nanostructured TiO₂ ultrafine powder with rutile phase produced using the homogeneous precipitation process at low temperatures (HPPLT) were compared with those of commercial P-25 TiO₂ powder by flame hydrolysis. The TiO₂ powder by the HPPLT showed much higher photoactivity in the removal rate, showing lower pH values in the solution than the P-25 powder when eliminating metal ions such as Pb and Cu from the aqueous metal-EDTA solutions. This can be inferred as the more rapid photo-oxidation or -reduction of metal ions from the aqueous solution, together with relatively higher efficiencies in the use of an electron-hole pair formed on the surface of the TiO₂ particles under UV light irradiation. Also, in the view of the TiO₂ particle morphology, compared to the well-dispersed spherical P-25 particles, the agglomerated TiO₂ secondary particles by the HPPLT consist of acicular typed primary particles with a thickness in the range of 3–7 nm and the primary particles radialize in all directions, which would be more effective to photocatalytic reactions without the large electron-hole recombination on the surface of the TiO₂ particle under UV light irradiation. It can be, therefore, thought that the higher photoactivity of the rutile TiO₂ powder by the HPPLT in the aqueous solutions results mainly from having a larger surface area by the acicular shaped primary particles with very thin thickness and radialization in all directions.     

紫外分光光度法测定聚硫密封胶中二氧化钛

基于强酸性溶液中钛氧离子与H2O2发生显色络合反应的原理,建立了浓硫酸–硫酸铵消解–紫外分光光度法测定聚硫密封胶中TiO_2含量的方法。通过对酸液和显色剂用量,以及显色络合物稳定性的系统考察,确定浓硫酸用量为2 mL,双氧水用量为3 mL,检测波长为403 nm。二氧化钛质量浓度在0~130μg/mL范围内与其吸光度呈良好的线性关系,线性方程为A=5.047 8c–0.019 31,r~2=0.999 2,检出限为0.08μg/mL。检测结果的相对标准偏差为0.89%(n=5),3水平加标平均回收率为101.7%。该方法线性范围较宽、检出限低、重复性好,可用于聚硫密封胶中二氧化钛的定量分析。     

次卟啉二甲酯钴络合物均相选择性催化氧化环己烷

以次卟啉二甲酯钴[Co(DPDME)]为仿生催化剂,分子氧（空气）为氧给体,无其它辅助催化剂的条件下研究了催化氧化环己烷的反应。考察了反应温度、空气压力、催化剂用量和卟啉配体结构对醇酮的产率及选择性的影响。结果表明,在相同条件下,次卟啉二甲酯钴的催化活性明显高于其它的钴卟啉催化剂。以次卟啉合钴为催化剂,浓度为0.015 mmol/L,反应温度423 K,在空气压强为0.8 MPa的条件下反应5 h,环己烷的转化率达到18.17％,选择性为87.43％。温度对次卟啉钴的催化活性影响较大,温度高于443 K时,催化剂的稳定性降低,但是其转化数仍达到了66 646。对次卟啉二甲酯钴催化空气氧化环己烷的反应路径作了初步探讨。     

Enhanced Adsorption Capacity and Photo-Catalytic Oxidative Activity of Dyes in Aqueous Medium by Hydrothermally Treated Titania Pillared Clay

Titania pillared montmorillonite clay was prepared by two different routes viz. 1) conventional ion exchange method and 2) modified method wherein the post hydrothermal treatment after ion-exchange was employed. The influence of the post hydrothermal treatment on the textural properties of titania-pillared clays was studied. The calcined clay was characterized by different physico-chemical techniques such as XRD, EDX, low temperature (77 K) nitrogen adsorption and UV-Vis diffuse reflectance spectroscopy. The content of pillared titania remained unchanged irrespective of the method of preparation. The method of preparation and severity of the conditions employed for the hydrothermal treatment resulted in alteration of the crystallinity and crystallite size of the anatase. The changes in the average pore diameter was found to comensurate with the changes in crystallite size of anatase phase. The increase in total pore volume as a function of the severity of the post hydrothermal treatment resulted in the decrease in micropore volume. The severity of the post hydrothermal treatment governed the extent of the blue shift in UV-Vis DRS spectra.The behaviour of titania pillared clays in adsorptive capacity and in photo-catalytic oxidation of methylene blue and victoria pure blue in aqueous medium was studied as a function of their physico-chemical characteristics. The titania pillared clays prepared by post hydrothermal route has shown enhanced adsorption capacity and photo-catalytic oxidation.     

纳米二氧化钛催化二苯并1,10-菲咯啉衍生物的合成研究

首次报道了纳米TiO_2催化1,2-环己二酮与2-氨基苯甲酰衍生物的串联Friedlander反应,合成了9个二苯并1,10-菲咯啉的衍生物(3a~3i),其中3b,3c,3e~3g和3i为新化合物,其结构经~1H NMR,~(13)C NMR和HRMS(ESI)表征。以6,7-二氢-5,8-二苯基苯并[1,10]菲咯啉(3a)的合成为例,对反应条件进行了优化。最佳反应条件为:锐钛型纳米二氧化钛用量为0.2 eq.,1a与2投料比为2.1∶1,乙腈为溶剂,于80℃反应7 h,收率83%。并对反应机理进行了探讨。     

假性紫罗兰酮合成中的碱催化剂

对近几十年来以柠檬和丙酮为原料,经Aldol缩合反应制备假性紫罗兰酮的研究进展作简要综述,着重讨论了碱催化剂对反应的影响,参考文献30篇。