纳米TiO2/ZrO2/Ce2O3复合薄膜的制备与光催化性能研究

采用溶胶-凝胶法分别制备了TiO2/ZrO2、TiO2/ZrO2/Ce2O3纳米复合薄膜.利用紫外-可见分光光度计、扫描电镜(SEM)等手段,对薄膜的光谱特性、晶粒尺寸、表面形貌进行了表征,并用分光光度法研究了复合薄膜对甲基橙溶液的降解,以及稀土铈离子对薄膜的光催化效率和抗失活稳定性的影响.结果表明,Ce3 可使TiO2/ZrO2薄膜中的晶粒尺寸减小,且晶粒在薄膜表面分布均匀致密,薄膜的光催化活性和抗失活稳定性均有较大提高.     

Mn2+对掺Ce3+BiB3O6纳米材料发光强度的影响

采用溶胶-凝胶的方法合成了一系列掺杂Mn2+,Ce3+的BiB3O6纳米发光材料.通过激发光谱和发射光谱研究了其发光性质,并探讨了Mn2+对Ce3+发光性能的影响.BiB3O6:Ce3+的发射光谱有位于370nm和405nm处的2个发射峰,由于Mn2+对Ce3+的敏化作用,Ce3+在BiB3O6:Ce3+,Mn2+中的发光强度有了显著的增强.     

Fe2O3-Al2O3-SiO2-TiO2抗菌、纳米湿敏陶瓷薄膜的Sol-Gel制备

利用溶胶凝胶法制成了Fe2O3-Al2O3-SiO2-TiO2抗菌、纳米湿敏陶瓷薄膜.用扫描电镜和原子力显微镜对膜的表面形貌和显微结构进行表征,分析了处理方式对膜的表面形貌和微观结构的影响.制成的Fe2O3-Al2O3-SiO2-TiO2抗菌、纳米湿敏陶瓷薄膜具有广谱抗菌、高效、无毒、持久和耐热等特点.湿敏特性测试结果表明:Fe2O3-Al2O3-SiO2-TiO2抗菌、纳米陶瓷薄膜制品的感湿灵敏度高,具有较好的响应特性和稳定性.     

水热法合成Ce_（0.9）Gd_（0.1）O_（1.95）及其光催化性质研究

采用水热法合成了花状Ce0.9Gd0.1O1.95纳米粉,通过X射线衍射、红外光谱、场发射扫描电子显微镜测试手段对产物进行了表征,探讨了其生长机制,以亚甲基蓝的光降解为模型反应,研究其光催化性能。结果表明,以甲酸为介质,110℃的水热条件下合成的纳米Ce0.9Gd0.1O1.95颗粒经800℃煅烧后具有萤石结构,平均晶粒尺寸为21.6 nm,花状形貌;由于Gd3＋的掺杂,纳米Ce0.9Gd0.1O1.95对亚甲基蓝紫外光催化性能强于未掺杂的CeO2。该合成方法简单易行,对纳米Ce0.9Gd0.1O1.95的形貌控制起到了启示作用,所得的花状纳米Ce0.9Gd0.1O1.95在光催化领域有着重要应用价值。     

水热法合成Ce0.9Gd0.1O1.95及其光催化性质研究

采用水热法合成了花状Ce0.9Gd0.1O1.95纳米粉,通过X射线衍射、红外光谱、场发射扫描电子显微镜测试手段对产物进行了表征,探讨了其生长机制,以亚甲基蓝的光降解为模型反应,研究其光催化性能。结果表明,以甲酸为介质,110℃的水热条件下合成的纳米Ce0.9Gd0.1O1.95颗粒经800℃煅烧后具有萤石结构,平均晶粒尺寸为21.6 nm,花状形貌;由于Gd3+的掺杂,纳米Ce0.9Gd0.1O1.95对亚甲基蓝紫外光催化性能强于未掺杂的CeO2。该合成方法简单易行,对纳米Ce0.9Gd0.1O1.95的形貌控制起到了启示作用,所得的花状纳米Ce0.9Gd0.1O1.95在光催化领域有着重要应用价值。     

氧化钐掺杂氧化铈纳米粉体的制备与性能表征

以Sin2O3，Ce（NO3）3H2O为原料，利用柠檬酸溶胶凝胶法制备Ce1-xSm2-0.5x纳米粉末，在1250℃下烧结成块体陶瓷材料。利用TG／DSC、XRD、SEM等表征方法分析纳米粉末和块体陶瓷的结构和性能，为Ce1-xSmxO3-0.5x在能源、化工、冶金、医学等领域的应用提供理论依据。     

Fe2O3-A12O3-SiO2-TiO2抗菌、纳米湿敏陶瓷薄膜的Sol-Gel制备

利用溶胶凝胶法制成了Fe2O3-Al2O3-SiO2-TiO2抗菌、纳米湿敏陶瓷薄膜。用扫描电镜和原子力显微镜对膜的表面形貌和显微结构进行表征，分析了处理方式对膜的表面形貌和微观结构的影响。制成的Fe2O3-Al2O3-SiO2-TiO2抗菌、纳米湿敏陶瓷薄膜具有广谱抗菌、高效、无毒、持久和耐热等特点。湿敏特性测试结果表明：Fe2O3-Al2O3-SiO2-TiO2抗菌、纳米陶瓷薄膜制品的感湿灵敏度高，具有较好的响应特性和稳定性。     

Ce_(0.7)Zr_(0.3)/γ-Al_2O_3纳米固溶体的制备及其结构

以氯氧化锆、硝酸铈、硝酸铝为原料,按n(Ce)∶n(Zr)=0.7∶0.3的比例,采用化学共沉淀法与有机物共沸蒸馏法,将CeO2、ZrO2分散到γ-Al2O3表面上使其形成Ce0.7Zr0.3O2/γ-Al23固溶体。用XRD考察纳米固溶体在不同温度下焙烧后的相结构。结果表明:Ce0.7Zr0.3O2/γ-Al2O3纳米固溶体为立方晶型,且随着焙烧温度的升高,样品的衍射峰依次变强,峰宽变窄。     

影响纳米CeO_2晶粒形貌的因素及机理

以Ce(NO3)3.6H2O为铈源,NH3.H2O为沉淀剂,用普通沉淀法在不同反应条件下制备了粒径、形貌各异的纳米CeO2。研究结果表明,Ce(NO3)3最佳浓度为0.2 mol/L。XRD和IR结果证实了产物的物相结构。TEM分析表明:控制pH可以得到形貌不同的纳米CeO2粒子。用乙醇作溶剂得到了粒径约为15 nm、分布均匀的纳米CeO2颗粒。正加料(沉淀剂滴入盐溶液中)可以得到各种形貌的纳米CeO2;而反加料(盐溶液滴入沉淀剂中)仅能得到针状纳米CeO2颗粒。     

Lu_2SiO_5:Ce透明薄膜的制备及其发光性能

采用溶胶-凝胶法,在无需气氛保护条件下以无机盐为原料在透明石英基底上旋涂制备Lu2SiO5:Ce(LSO:Ce)透明薄膜。利用X射线衍射仪、扫描电子显微镜和分光光度计测定了薄膜的结构、厚度、透过率和光致发光性能。结果表明:溶胶-凝胶法制备LSO:Ce薄膜所需结晶温度为1200℃,薄膜单层厚度为400nm,在可见光范围内透过率约为80%,发射波长为383nm,衰减时间约为31ns。     

Spin and dip coating of light-emitting polymer solutions: Matching experiment with modelling

This paper reports experimental observations on spin and dip coating of light-emitting polymer (LEP) solutions where both the process conditions as well as the solution properties are factors influencing thickness and uniformity of thin LEP films. In terms of spin coating, which is a typical process for the manufacture of polymer light-emitting diodes (PLEDs), a number of process variables including spin speed were systematically explored. A matching series of dip-coating experiments was also carried out with the retraction speed as a primary variable. Modifications of existing models for both spin and dip coating were developed to include solvent evaporation and the effect of solution viscosity change during evaporation. Both models were found to give reasonable agreement with the major observed trends for final film thickness as a function of process conditions tested in this paper.     

纳米二氧化钛光催化薄膜的制备研究进展

主要根据近5年来国内外TiO2薄膜制备的研究现状,对TiO2薄膜的各种制备技术进行了综述,其中包括液相沉积法、溶胶一凝胶法、气相沉积法和电化学法,对各方法的优点和缺点进行了评述。并对TiO2薄膜未来研究方向提出了建议。     

Characterization of antireflective coatings on poly(methyl methacrylate) substrate by different process parameters

The high/low refractive index organic/inorganic antireflective (AR) hybrid polymers were formed using the sol–gel process, in which TiO₂/2‐hydroxyethyl methacrylate (2‐HEMA) (high refractive index hybrid polymer) and SiO₂/2‐HEMA (low refractive index hybrid polymer) two‐layer thin films were formed on a hard coating deposited poly(methyl methacrylate) (HC‐PMMA) substrate by both spin coating and dip coating. The relationship between the process parameters and the optical properties, thickness, porosity, surface morphology, and adhesion was determined. The results show that the reflectance of the two‐layer thin films on HC‐PMMA substrate is less than 0.21% (λ = 550 nm), with good adhesion (5B) and a hardness of up to 4H. In addition, the thickness, porosity, and roughness of the films affect refractive index and the antireflection properties of the AR two‐layered thin film. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Development of multiple-droplet drop-casting method for the fabrication of coatings and thin solid films

Spray coating is a commercial and low-cost technique for the fabrication of large-area coatings and thin films, but it is a stochastic process that is hard to control, as far as the fabrication of thin coatings and solid films is concerned. On the other hand, drop-casting is a facile and more controllable coating technique than spray coating, but its application is limited to small-area thin solid films and coatings. The objective of this work is, therefore, to study the feasibility of impinging an array of droplets, rather than just one droplet, to fabricate polymeric and other solution-processed thin films with larger surface areas than those produced by conventional drop-casting. To this end, in this study, four droplets of poly(3,4-ethylenedioxythiophene)–polystyrene sulfonate (PEDOT:PSS) solution are released simultaneously and impinged on the four vertices of a square on a wettable solid surface to make a thin film. The effect of the substrate texture on the spreading and the film formation process is studied. As a novel idea, the substrate is excited by ultrasonic vibration to improve the droplet spreading and coalescence. It is shown that as time elapses, the impinged droplets successfully coalesce and make a thin film. Surface morphology and roughness of the resulting PEDOT:PSS thin solid films show that, except on the edges, the resulting thin solid films are uniform. This leads us to conclude that the application of equal-sized and equally-spaced multiple droplets released simultaneously and impinged on vibrating substrates could be considered as a new coating technique, which has some of the benefits of the spray coating, but it is much more controllable than spray coating.     

Chemical solution deposition of pure and Gd-doped ceria thin films: Structural,morphological and optical properties

High quality smooth, uniform and crack-free ceria and gadolinium doped ceria (GDC) thin films were prepared on Si and Si/YSZ substrates by chemical solution deposition. The thermal behavior of Gd-Ce-O precursor was investigated by TG-DSC measurements. The phase purity and structure of deposited films were evaluated using X-ray diffraction (XRD) analysis and Raman spectroscopy. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were employed for the estimation of surface morphological features. Oxidation state of Ce ions in fabricated films was analyzed by X-ray photoelectron spectroscopy (XPS). Optical properties were evaluated by diffuse reflectance UV–vis spectrometry. Thickness of the films can be controlled by applying a certain number of spin coating cycles. A linear relation between the thickness of the films and the number of deposited layers was observed. The single-layer thickness was determined to be approximately 20 nm. The influence of annealing temperature and Gd content on the film structure, morphology and optical properties was studied and discussed. The dependence of an optical band gap as a function of grain size was demonstrated.     

Barrier coatings on cellulose fiber mat

Two techniques were used in the deposition of thin, pinhole-free vapor barriers upon a Kraft fiber mat without affecting its combustibility properties. One technique involved a collodion spray precoating followed by low pressure styrene plasma coating, and the other involved a collodion spray coating. In the formation of the above coatings, two functional steps are essential: (1) surface pore covering, and (2) nonporous barrier formation.     

纳米TiO_2薄膜的结构及紫外可见光谱研究

本文以钛酸丁酯[Ti(OC4H9)4]、盐酸和去离子水为原料,采用溶胶-凝胶法和旋转涂膜工艺,在玻璃基片上制备透明的TiO2纳米薄膜。通过XRD测试表明:经500°C退火得到的薄膜上TiO2为锐钛矿晶相而粉末为锐钛矿、金红石和板钛矿的混合晶相。通过对膜进行紫外可见光谱分析,探讨了影响TiO2纳米膜厚度和禁带宽度的各种因素。实验结果表明:溶胶的陈化时间、膜的热处理温度、涂膜层数等都将直接影响二氧化钛薄膜的紫外可见光谱和禁带宽。     

Spin coated versus dip coated electrochromic tungsten oxide films: Structure, morphology, optical and electrochemical properties

A sol-gel derived acetylated peroxotungstic acid sol encompassing 4 wt.% of oxalic acid dihydrate (OAD) has been employed for the deposition of tungsten oxide (WO₃) films by spin coating and dip coating techniques, in view of smart window applications. The morphological and structural evolution of the as-deposited spin and dip coated films as a function of annealing temperature (250 and 500 °C) has been examined and compared by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). A conspicuous feature of the dip coated film (annealed at 250 °C) is that its electrochromic and electrochemical properties ameliorate with cycling without degradation in contrast to the spin coated film for which these properties deteriorate under repetitive cycling. A comparative study of spin and dip coated nanostructured thin films (annealed at 250 °C) revealed a superior performance for the cycled dip coated film in terms of higher transmission modulation and coloration efficiency in solar and photopic regions, faster switching speed, higher electrochemical activity as well as charge storage capacity. While the dip coated film could endure 2500 color-bleach cycles, the spin coated film could sustain only a 1000 cycles. The better cycling stability of the dip coated film which is a repercussion of a balance between optimal water content, porosity and grain size hints at its potential for electrochromic window applications.     

Characterization and Investigation of the Tribological Properties of Sol–Gel Zirconia Thin Films

Sol–gel zirconia thin films were prepared by dip coating in an ethanol solution of zirconium oxychloride. The zirconia films consisted of a completely tetragonal phase and exhibited nanoscale uniformity. They displayed excellent antiwear and friction-reduction performance in sliding against steel. The friction coefficient (0.13–0.15) and the wear life over 5000 sliding cycles were recorded for the films at a sliding speed of 90 mm/min and a load of 0.5 N. The film was characterized by slight scuffing and abrasion at low loads and sliding speeds.     

Effective Air‐Spray Deposition of Thin Films Obtained by Sol–Gel Process onto Complex Pieces of Sanitary Ware

A deposition mechanism by air‐spray technique is carried out for depositing silica‐based thin films obtained by the sol–gel process. The air‐spray deposition is very useful to coat large and complex surfaces with different morphologies and roughnesses which favors the technology scale‐up, contrary to the most used deposition methods in the sol–gel process (dip and spin coating). To establish the adequate conditions of these techniques, a complete study of the sol properties (rheology, FT‐IR, roughness, thickness) is attempted, which has allowed determining the parameters for the effective air‐spray deposition of homogeneous thin films. By means of an experimental design, it has been possible to validate the selected parameters. Finally, a scheme of an effective spray deposition model is proposed for a better understanding of the deposition mechanisms.