The Synthesis of Sulfated Titanium Oxide Nanotubes

TiO₂ nanotubes can be prepared in gram quantities by treating anatase TiO₂ powder with concentrated NaOH solution. These TiO₂ nanotubes acquired strong acidity after being impregnated with sulfuric acid solution and calcined at 300 °C. The anatase TiO₂ powder used to prepare the nanotube did not catalyze the esterification between cyclohexanol and acetic acid, while sulfated TiO₂ nanotubes were very reactive toward the esterification reaction.     

Thermal Decomposition of Titanium Alkoxide and Silicate Ester in Organic Solvent: A New Method for Synthesizing Large-Surface-Area, Silica-Modified Titanium(IV) Oxide of High Thermal Stability

Silica-modified titanium oxide (S-TiO₂) powders that have an anatase structure were synthesized via the thermal decomposition of mixtures of titanium(IV) isopropoxide (TIP) and tetramethyl orthosilicate (TMOS) in toluene at 300°C. These S-TiO₂ materials had high rutile-transformation temperatures and maintained large surface areas at elevated temperatures (550°–1000°C). For example, the product that was prepared from a 9:1 TIP:TMOS mixture transformed to rutile at ∼1100°C and possessed a surface area of 160 m²/g, even after calcination at 800°C for 1 h.     

Optical Basicity of Titanium(IV) Oxide and Zirconium(IV) Oxide

The relationship between electronic polarizability of oxide(—II), α_O²⁻, and the electron donor power, expressed as the optical basicity, ∧, indicates that ∧(TiO₂) is much greater than ∧(SiO₂) and is approximately the same as ∧(CaO). Such a high basicity is supported by the trend in the Racah B parameter for the Ni²⁺ ion in crystalline hosts and is also indicated from α_O²⁻ values of glasses containing TiO₂. Electronic polarizability and other data for zirconium(IV) media indicate that ZrO₂ also has a high basicity, but that ∧(ZrO₂) is somewhat less than ∧(TiO₂).     

Effective Photocatalytic Reduction of Nitrate to Ammonia in an Aqueous Suspension of Metal-Loaded Titanium(IV) Oxide Particles in the Presence of Oxalic Acid

Photocatalytic reduction of nitrate ion (NO₃ ^–) in an aqueous suspension of metal-loaded titanium(IV) oxide (TiO₂) was examined in the presence of oxalic acid (OA) as a hole scavenger. Conversion of NO₃ ^– into ammonia (NH₃) competed with hydrogen liberation, and the NH₃ production selectivity increased with the order of loaded metal, (Pt, Pd, Co) < (Ni, Au) < (Ag, Cu), which was attributable to the efficiency of reduction of protons by photogenerated electrons at the loaded metal, i.e., hydrogen overvoltage of the loaded metal. TiO₂ powder loaded with Cu showed higher NH₃ yield and selectivity as well as higher efficiency of OA consumption. TiO₂ with in situ deposited Cu gave results comparable to those of a Cu pre-loaded photocatalyst.     

半导体纳米材料TiO2的光催化应用

对半导体光催化剂TiO2在有机污染物的处理，光催化化学合成、杀菌、汽车工业，红外线反向材料等方面作了介绍。综述了国内外此类催化剂研究的最新进展，提出了光催化研究方面存在的问题。     

表面修饰的Fe~(3+)/TiO_2制备研究

采用微波水热法制备了表面包覆有硬脂酸的铁掺杂的二氧化钛纳米粒子,对其微结构进行了表征。结果表明:产物为表面包覆有硬脂酸Fe3+ /TiO2 的纳米复合粒子,粒度分布均匀且单分散性好,平均粒径约为38nm;表面为非极性,紫外透过率较低,催化活性较低。可用于防晒化妆品。     

二氧化钛和氧化锌的光催化活性(英)

通过二氧化钛和氧化锌的光催化作用研究,讨论了有机及无机表面处理对该作用的影响。与无机处理相比,有机表面处理对降低二氧化钛和氧化锌的光催化活性有很大影响,进而显著地减小了其在化妆品中的副作用,具有重要的意义。     

Optical Basicity of Titanium(IV) Oxide

The relationship between phosphate and vanadate capacites and optical basicity, Λ, are used in order to settle the optical basicity of TiO₂. Phosphate and vanadate capacity data indicate that the optical basicity of TiO₂ is 0.55. The validity of this value is supported by the good agreement with the value derived from Pauling electronegativity.     

叶腊石／TiO2复合粉体的制备及其抗紫外线性能研究

以叶腊石和钛白粉为主要原料,采用机械力化学法在叶腊石表面包覆钛白粉,制备一种无机复合型紫外吸收材料。用分光光度计分别在波长为330nm、350nm、370nm、390nm下测定复合材料的紫外光透过性能。结果表明：钛白粉包覆量、煅烧温度、煅烧时间、球磨机转速、球磨时间对叶腊石／TiO：复合粉体材料的紫外光透过率有重要影响,优化条件下制得的复合粉体材料紫外透光度明显低于叶腊石原粉,低于市售ZnO2且在各个波长的紫外透光度均低于5％。SEM表明：叶腊石表面包覆一层二氧化钛粒子。粒子成球状,粒径在200-450nm左右。     

Kinetics of Titanium(IV) Chloride Oxidation

The oxidation rate of TiCl₄ vapor was measured by FTIR spectroscopy between 700° and 1000°C in a furnace aerosol reactor. The reaction rate was found to be first order with respect to TiCl₄ and to follow the Arrhenius form. The apparent activation energy for the reaction was 88.8 ± 3.2 kJ/mol and the preexponential factor 8.26 × 10⁴ s⁻¹. A kinetic mechanism for the oxidation of TiCl₄ was proposed that was consistent with the observed dependence of oxygen concentration on the apparent rate constant.     

Low-Temperature Creep of Nanocrystalline Titanium(IV) Oxide

Nanocrystalline TiO₂ with densities higher than 99% of rutile has been deformed in compression without fracture at temperatures between 600° and 800°C. The total strains exceed 0.6 at strain rates as high as 10⁻³ s⁻¹. The original average grain size of 40 nm increases during the creep deformation to final values in the range of 120 to 1000 nm depending on the temperature and total deformation. The stress exponent of the strain rate, n , is approximately 3 and the grain size dependence is d ^{− q} with q in the range of 1 to 1.5. It is concluded that the creep deformation occurs by an interface reaction controlled mechanism.     

碳酸钙基复合钛白制备研究

在CO2气体浓度和晶型控制剂H2SO4加入量不变的条件下,采用间歇鼓泡碳化法制备碳酸钙基复合钛白。研究了Ca(OH)2初始浓度、CO2气体流量的优化参数。结果表明:TiO2颗粒比较稳定地镶嵌在碳酸钙基体上,随反应时间的进行,pH值逐渐由13下降到7左右,随CO2气体流量增加,反应总时间减少;随Ca(OH)2初始浓度增加,反应总时间增加,复合钛白平均粒径增大,最佳Ca(OH)2初始浓度为10.5%~12%。     

二氧化钛与血红蛋白相互作用的光谱研究

利用紫外可见吸收光谱和荧光光谱研究了自制的TiO2与血红蛋白在两种酸度条件下的相互作用,并对两者相互作用的机理进行了初步探讨。     

光触媒纳米二氧化钛应用研究

将纳米TiO2制备戍含氟反相乳液，再利用超临界CO2流体技术将分散在乳液中的TiO2粒子注入纤维之中，制备戍具有光自洁功能的纤维制品，将其置于含有甲醛气体的密闭容器中，在不同功率的紫外光源照射下，测定密闭容器中甲醛气体随时间的变化率，以探讨纳米TiO2对有害气体的分解能力，对纳米TiO2微粒的乳化与分散、晶型、结构类型和添加剂等影响光催化效率的若干因素也进行了讨论。     

分散剂对二氧化钛分散性能的影响

用沉淀法来研究超细二氧化钛在水中的分散情况,对比了自制产品丙烯酸-2-丙烯酰胺-2-甲基丙磺酸共聚物（AMAMPS）钠盐和国外分散剂产品YUS-WG5（聚羧酸酯）在不同分散剂用量、不同溶液的pH值时对水相中二氧化钛分散情况的影响,实验证明两者的分散性能相当,可以替代国外产品进行使用。     

Nitridation of the Sol–Gel-Derived Titanium Oxide Films by Heating in Ammonia Gas

Dip-coated sol–gel-derived TiO₂ films on an alumina substrate were converted to nonstoichiometric titanium nitride (TiN _x ( x ≦ 1)) films by heating at approxmately 1000°C in NH₃ gas. TiO₂ films made from TiO₂ sols prepared from Ti(O– i -C₃H₇)₄ and stabilized by diethanolamine were more easily nitrided than those from sols containing HCl as a deflocculant reagent. This appears to be a result of the more porous structure of the former films.     

均相沉淀-发泡法制备纳米氧化钛及其表征分析

采用Ti（SO4），和尿素为原料，利用均相沉淀．发泡工艺制备出了纳米氧化钛粉体材料，并用DTA-TG、XRD、IR和FS等方法对样品进行了表征。DTA-TG结果表明TiO2样品在高温固相反应期间有两个明显的失重台阶。XRD分析表明，在500℃下焙烧的TiO2样品为相纯度较高的锐钛矿型氧化钛粉体，其平均粒径约为12．834nm。IR谱图显示随着烧结温度的升高，450～800cm^-1处Ti-O键的伸缩振动峰出现分裂，且峰形逐渐锐化，表明纳米样品的尺寸有所增大。FS分析表明在365nm激发波长下，600℃煅烧下生成的混合晶型的纳米氧化钛具有最强受激发射峰，而在393nm激发光下。500℃煅烧下生成的锐钛矿型氧化钛具有最强受激发射峰。     

Sulfonated Poly (Ether Ether Ketone) / Barium Strontium Titanium Oxide Polymer Nanocomposite Membranes for Fuel Cell Applications

ABSTRACT

Polymer nanocomposite membranes based on sulfonated poly (ether ether ketone) (SPEEK) and barium strontium titanium oxide (BSTO) have been prepared by solution casting technique. The SPEEK was obtained by direct sulfonation of poly (ether ether ketone) using concentrated sulfuric acid. The degree of sulfonation of SPEEK was determined by ¹H NMR spectroscopy. The composite membranes showed higher water uptake capacity when compared to SPEEK. The ion-exchange capacity of the composite membranes was found in the range between 1.48 and 1.62 meq. g^?1. The thermal stability of composite membrane was found to be good enough to use in fuel cell.     

多色钛阳极氧化膜的耐蚀性研究

钛阳极氧化膜由于其特殊的性能而得到广泛作用。在此通过测量钛阳极氧化膜在０．０５ｍｏｌ／Ｌ氢氟酸溶液中的腐蚀电位随时间的变化以研究其耐蚀性。分析了膜层厚度、膜的形成温度及时间对其耐蚀性的影响。     

Phase relations in the Barium Titanate—Titanium Oxide System

Phase relations in the BaTiO₃—TiO₂ system were studied at temperatures above 1300°C in air. Quenching experiments were performed with high-purity reagents, and a new equilibrium phase diagram was constructed. Results include redetermination of the liquidus boundaries, the eutectic temperature, the melting or decomposition temperatures of the stable compounds in the system, the cubic—hexagonal transition in BaTiO₃, and the solid solubility of TiO₂ in BaTiO₃.