Sol-Gel Preparation of Graphite/TiO_2 Composite Particles and Their Electrorheological Effect

Graphite/TiO2 composite particles were obtained by sol-gel technique in this paper. The structure and characteristic of the composite particles are analyzed by XRD, SEM and TG-DTA. The electrorheological properties of the ER fluid containing the particles were measured by a Couette-type rheometer under shear rates of 1-136 s-1 and AC electric fields of 0-3 kV/mm. The experimental results show that the leaking current density of the ER fluid is higher than that of pure titanium dioxide particles dispersed in damping oil. The shear yield stress of the ER fluid increases with increasing electric field and exhibits a typical Bingham flow behavior. The suspension demonstrates an excellent ER performance (τ/τo=1200) compared with conventional ER fluids (τ/τ0 ≤500). The sedimentation of the ER fluid is improved obviously due to the coating effect of the particles.

Sensitization of Microporous Nanocrystalline TiO_2 Electrode with Quantum Sized RuS2 Particles

The microporous nanocry'sta1line TiO2 electrode with large surface roughness factor hasbeen prepared on a conducting glass support. Modification of the TiO2 electrode by in situ preparingquantum sized RuS2 particles on the surface of TiO2 electrode extends the optical absorptionspectrum and photocurrent action specmim into visible region. In addition, compared with RuS2 bulknlaterials- a blue shifi in both absorption spectrum and photocurrent action speCtrum of RuS2rriO2elcctrode is obserived and explained in terms of quantum sized effect.

Rendering of Cellulose Acetate Fabrics Self-Cleaning through Treatment with TiO₂Nano Particles

Finishing using TiO2-nanosol treatment of cellulose acetate (CA) fabrics before and after the latter were pretreated with H2O2was undertaken with a view to impart unique properties to CA fabrics, notably, self-cleaning. Finishing was performed as per the pad-dry-cure method. The finishing treatment involved dispersing the nano-sized TiO2particles in a mixture of water and ethylene glycol (1:1) and application of the dispersions to CA fabrics was made under a variety of conditions. Self cleaning ability of the fabrics is favored by 1) increasing the concentration of TiO2-nanosol to certain limit;2) prolongation of curing time up to 15 second;3) raising the microwave power from 80% to 100% but with the certainty that power of 90% is the most proper. Besides, exposure time-to UV radiation-up to 90 minutes is essential to have remarkable self cleaning properties while keeping other technical properties, namely, strength, roughness and wettability practically unaltered. Incorporation of binder in the finishing pad-bath helps stabilizing the deposition of TiO2 with excellent self-cleaning. Pretreatment of CA fabrics with H2O2 is a pre requisite to guarantee excellent self-cleaning ability. Thermofixation and microwave fixation produces fabrics with very comparable technical properties.

Characterization of Calcined Kaolin/TiO_2 Composite Particle Material Prepared by Mechano-Chemical Method

Calcined kaolin/TiO2 composite particle material （CK/TCPM） was prepared with TiO2 coating on the surfaces of calcined kaolin particles by the mechano-chemical method. X-ray diffraction （XRD） and scanning electron microscope （SEM） were used to investigate the microstructures and morphologies, respectively. The mechanism of the mechano-chemical reaction between calcined kaolin and TiO2 was studied by infrared spectra （IR）. The results show that TiO2 coats evenly on the surfaces of calcined kaolin particles by Si-O-Ti and Al-O-Ti bonds on their interfaces. The hiding power and whiteness of CK/TCPM are 17.12 g/m^2 and 95.7%, respectively, presenting its similarity to TiO2 in pigment properties.

Preparation of Multifunctional β-hemihydrate Gypsum using Oyster Shell Powder as the Partial Replacement of Ag/TiO2 Particle

This work aimed to use oyster shell powder (OSP) as the partial replacement of Ag/TiO2 particle to obtain multifunctional β-hemihydrate gypsum.Thus,the β-hemihydrate gypsum was mixed with different contents of OSP and Ag/TiO2 particle.Antibacterial and MB removal experiments were conducted to assess the antibacterial characteristic and photocatalytic activity of β-hemihydrate gypsum with Ag/TiO2 particle and OSP.Besides,the formaldehyde degradation test was carried out to evaluate its formaldehyde removal ratio.Moreover,their setting times,compressive and flexural strengths at 1,3,and 28 days were comparatively analyzed.The experimental results prove that the composite use of OSP and Ag/TiO2 particle provide feasible multifunction for the β-hemihydrate gypsum.They can further improve the bactericidal rates and exhibit extra MB removal ratios compared with the gypsum plasters with single Ag/TiO2 particle.Besides,they can increase the formaldehyde degradation ratios,and this promotion is related to the introduction of Ag/TiO2 particle.However,OSP delays the initial setting time but promotes the final setting time of β-hemihydrate gypsum,and Ag/TiO2 particle hardly affects the setting times.Furthermore,OSP reduces the strengths of plasters at 1,3,and 28 days.But in general,the composite addition of OSP and Ag/TiO2 particle increase the compressive and flexural strengths of gypsum plasters at 1,3,and 28 days.These results provide theoretical guidance for the recycling of OSP and the preparation of gypsum-based products with antibacterial and formaldehyde degradation capabilities.

Fe^(3+)/TiO_2/SiO_2复合纳米微粒的合成及光催化降解NO_2^-

采用溶胶 -凝胶法制备了 Ti O2 / Si O2 和不同浓度 Fe3+掺杂的 Fe3+ / Ti O2 / Si O2 复合纳米粉末 ,并利用XRD、BET、UV-vis等手段研究了 Ti O2 / Si O2 及掺铁形成的 Fe3+ / Ti O2 / Si O2 复合微粒的表面结构形态变化 ,以及对污染物 NO- 2 光催化降解的影响 .结果表明 ,Fe3+ / Ti O2 / Si O2 (ω( Fe3+ ) =1 .5 % ,m( Ti)∶ m( Si) =2∶ 1 )具有最佳活性 ,样品呈晶化度较低的锐钛矿结构 .Fe3+ 掺杂导致晶粒的增大 ,稳定性降低 ,大大提高了半导体的光催化活性 ,有利于对低浓度 NO- 2

纳米TiO_2的性能、应用及制备方法

纳米 Ti O2 具有独特的光催化性、优异的颜色效应以及紫外线屏蔽等功能 ,在光催化剂、化妆品、抗紫外线吸收剂、功能陶瓷、气敏传感器件等方面具有广阔的应用前景 ,国内外文献对纳米 Ti O2 的性质、应用及其制备方法进行了大量的研究报道。本工作对有关纳米 Ti O2的性能。

光催化剂TiO_2超细粒子的制备及改进评述

Ti O2 超细粒子作为常用的光催化剂 ,在环境净化中日益受到重视 .本文对 Ti O2 超细粒子的作用机理 。

纳米SnO2@TiO2包覆催化剂的制备及表征

采用活性层包覆法在自制超细SnO2胶体粒子表面包覆TiO2, 制备出SnO2@TiO2包覆型复合催化剂, 以其对有机磷农药DDVP的降解效果作为评价光催化活性的标准, 对制备条件进行了优化, 并用XRD、 TEM和BET等手段对样品进行了表征. 结果表明, SnO2胶体乙醇溶液含水量20％, 钛酸丁酯质量分数为34.5％, 灼烧温度680 ℃时制得TiO2含量56.45%的包覆样品SnO2@TiO2为纳米级粒子,且其光催化活性最佳.

Fe^(3+)/V^(5+)TiO_2复合纳米微粒光催化性能的研究

采用溶胶凝胶法制备了Fe3+ V5+ TiO2 复合纳米微粒作为光催化剂。光降解反应结果表明 ,共掺杂催化剂Fe3+ V5+ TiO2 的光催化活性明显提高。光电化学研究显示 ,铁离子可以成为电荷陷阱 ,促进空穴的界面传递反应。适量钒离子掺杂使TiO2 电极的光电流升高 ,导带中电子浓度的增大 ,加快了界面的电子传递反应。共掺杂催化剂中 ,Fe3+ 、V5+ 分别提供了空穴与电子的陷阱 ,同时加快了电子与空穴的界面传递反应 ,从而更有效地提高光催化活性。双组份共掺杂为提高TiO2 光催化活性提供新的途径。

SiO_2-TiO_2复合微粒的研究

通过溶胶法制备了 18nm和 40 nm两种粒径均匀、单分散的 Si O2 - Ti O2 复合微粒 ,确定了最佳合成条件。电镜照片显示 ,水和 Ti O2 粒子接枝于 Si O2 粒子表面 ,成针状向外生长。对包覆过程、复合纳米粉末煅烧行为、表面改性的研究表明 ,110 0℃～ 12 0 0℃ Ti O2 由锐钛型向金红石型转变 ,Si O2 的鳞石英晶型也开始形成。甲醇改性的 TS纳米粉末能较好的再分散于乙醇中。

超微粒TiO_2对U937细胞光杀伤效应及机理研究

超微粒TiO2 经光催化氧化后对U937白血病细胞有明显的杀伤作用 ,DNA琼脂糖凝胶电泳图证明了光激发TiO2 能够损伤细胞内的DNA ,从而导致细胞死亡 。

TiO_2纳米粒子改性有机醇酸涂料性能研究

利用金红石型TiO2 纳米粒子改性醇酸涂料提高醇酸涂料的各种性能 .结合物理和化学分散 ,并选取合适的分散剂 ,解决了TiO2 纳米粒子在醇酸涂料中的分散问题 ;性能测试结果表明 ,与普通钛白粉醇酸涂层相比 ,TiO2 纳米粒子改性醇酸涂层具有很强的抗紫外线性。

(Ni-P)-纳米TiO_2微粒化学复合镀层的摩擦特性

通过对化学镀 Ni- P合金、化学复合镀 ( Ni- P) -微米 Si C微粒复合镀层和化学复合镀 ( Ni- P) -纳米 Ti O2 微粒复合镀层研究与比较 ,探讨了化学复合镀 ( Ni- P) -纳米 Ti O2 微粒复合镀层的摩擦学特性。研究发现化学复合镀 ( Ni- P) -纳米 Ti O2 微粒复合镀层由于其良好的组织与性能 ,滑动磨损过程中具有低的摩擦系数和高的耐磨性。

TiO_2 微粒的掺杂改性与催化活性

用混合溶胶 凝胶法制备了Fe3+,Zn2 +,Pd ,Co2 +,Ni2 +,Cr3+等金属离子掺杂的二氧化钛复合微粒。以四环素降解为目标反应 ,研究了所制备的复合微粒光催化活性与选择性。并用IR、XPS、Raman光谱等技术 ,探讨了影响复合微粒光催化活性的原因。结果显示 :掺杂Fe3+、Zn2 +的二氧化钛复合微粒对四环素降解具有很高的催化活性与选择性 ;掺杂Pd的复合微粒催化活性也有所提高。而Co2 +,Ni2 +,Cr3+等金属离子掺杂的二氧化钛复合微粒的催化活性呈下降趋势。研究认为 :Fe3+、Zn2 +促进二氧化钛微粒光催化活性的原因是由于这些金属离子高度分散在二氧化钛基质中 ,使基质晶型发生畸变并形成Ti O M桥氧结构 ;这种结构使复合微粒表面缺陷和活性比表面积增加 ,有利于光生载流子的转移。同时 ,Ti/Fe复合微粒中Fe3+有利于活性·OH基团的形成。这些活性·OH基团插入有机物的C H键中 ,最终导致有机物的完全降解矿化。另一方面 ,由于Fe3+,Zn2 +,Pd特殊的电子构型 ,有利于浅度捕获半导体的光生电子 ,使光生电子 空穴对有效分离。而Co2 +,Ni2 +,Cr3+金属离子的电子构型易深度捕获光生电子 ,结果可能形成了电子 空穴复合中心 ;

纳米级TiO_2粉体的制备研究Ⅰ.pH值的影响

采用无机盐作为前驱物，利用溶胶凝胶超临界流体干燥（ＳＣＦＤ）法，制备出大孔、高比表面纳米级ＴｉＯ２超细粉。详细考察了初始水凝胶ｐＨ值对ＴｉＯ２超细粉形貌、晶相、颗粒大小、比表面积及孔结构等的影响。实验结果发现：当在酸性环境中，所制得的ＴｉＯ２超细粉的比表面积随着ｐＨ值的减小而增大；而在碱性环境中，则随着ｐＨ值的增大而增大。ＴｉＯ２超细粉的比表面积和孔体积由ｐＨ为６．５时的ＳＢＥＴ＝１４２．２ｍ２·ｇ１，ＶＰＮ＝０．４５ｃｍ３·ｇ１，增大到ｐＨ值为１３．０时的ＳＢＥＴ＝４２５．６ｍ２·ｇ１，ＶＰＮ＝１．７９ｃｍ３·ｇ１，且颗粒分布均匀狭窄，颗粒间的三维网络织构更为规整清晰。

陶瓷微滤膜回收钛白粉水洗液中TiO_2颗粒中试与现场考核

对陶瓷微滤膜回收钛白粉水洗液中二氧化钛粒子进行了中试实验和现场考核 ,考察了错流速度、浓度对渗透通量的影响及湍流促进器对微滤过程的强化效果 ;建立了日处理 15 0t废水的陶瓷膜回收钛白粉成套装置 ,并对该装置进行了现场运行性能考察和经济核算。实验结果表明 ,采用陶瓷膜微滤技术回收钛白粉水洗液中二氧化钛粒子不仅在技术上是可行的 ,在经济上也是合理的。

TiO_2多孔纳米微粒的制备及其物性表征

首次利用高分子悬浮聚合与溶胶 -凝胶法相结合的技术 ,成功地制备了具有中空结构的TiO2 多孔微粒 ,并用X -Ray、SEM、自动气体吸附仪等手段对其物理性质进行了系统表征 ,在最优pH条件下制备的TiO2 微粒比表面可达 6 7.5m2 /g ,平均粒径为 2 μm ,孔体积为 0 .1cm3 /g。与商品纳米TiO2 相比 ,其微米尺寸使其具有易于分离和重复使用等优点 ,晶粒的结构特点决定了其具有高催化活性。

纳米TiO_2的制备与表征

通过金属醇盐水解制备了纳米TiO2 颗粒 ,用XRD、TEM、ICP等方法进行了分析与表征 ,给出了相关的工艺参数。实验结果表明 ,通过控制溶液的pH值和水解用水量 。

纳米TiO_2的晶型、粒径与光催化活性

分析了纳米 Ti O2 的晶型、粒径与光催化活性的关系 ,指出了高催化活性下的晶型和控制晶型的条件以及高催化活性下的粒径范围和保持粒子分散的方法。