溶胶-凝胶法制备稀土铽配合物掺杂的发光薄膜

采用溶胶－凝胶法原位制备了稀土配合物掺杂的发光薄膜，薄膜透明均一。结果表明用原位合成法，可以将难溶性稀土羧酸类配合物有效地掺杂到溶胶基质中，荧光光谱分析表明，所得到的薄膜材料在紫外激发下发射出铽离子的特征发射线。     

酸催化溶胶-凝胶法制备高强度SiO2增透膜研究进展

高强度增透膜是用于减少表面反射、增加光线透光率的薄膜,具有密度低、折射率可调、耐磨性好的特点.本文综述了高强度增透膜的制备方法与研究进展,介绍了酸催化溶胶-凝胶法制备SiO2溶胶的机理及影响因素,酸催化溶胶-凝胶法及两种辅助酸催化溶胶-凝胶法制备高强度增透膜的方法,对高强增透膜制备的发展方向和应用前景进行了展望.     

溶胶凝胶法制备光催化薄膜材料及其性能表征

采用溶胶凝胶法制备TiO2胶体,再采用旋涂法在玻璃基体上负载得到TiO2薄膜,并对制备的TiO2结构进行表征,以2,4二-氯苯酚为探针,考察薄膜的光催化性能。通过实验,学生基本了解溶胶-凝胶法的原理、薄膜的制备方法、光催化剂的性能表征,可以作为开放性实验。     

荧光素衍生物LB膜对TiO2电极的光敏化作用

合成了三种荧光素长碳链衍生物，通过LB技术将它们组装成单分子薄膜，修饰在用溶胶-凝胶法制备的TiO2透明电极上，研究了这些LB膜的结构和特性及它对TiO2的光增感作用．并对其光敏化机理作了阐述．     

SnO2纳米薄膜的制备、显微结构及气敏性能

SnO2纳米薄膜的制备、显微结构及气敏性能;SnO2薄膜;溶胶-凝胶法     

紫外光照射对掺铝氧化锌薄膜导电和透光性质的影响

本文采用光助溶胶—凝胶法制备了掺铝氧化锌(AZO)透明导电薄膜.研究了紫外光照射对薄膜导电性和透光性质的影响.结果表明:光照使薄膜的导电性显著提高,且光照后薄膜方阻的降低幅度随薄膜晶粒尺寸的减小而逐渐增加;而随着紫外光照射时间延长,薄膜的紫外吸收边蓝移,近红外区透光率降低.以上实验现象可能与表面吸附氧解吸引起的载流子浓度增加、迁移率升高以及分层退火处理形成的薄膜结构有关.     

热处理对WO3纳米薄膜结构及其气致变色性能的影响

以钨粉和过氧化氢溶液为原料, 采用溶胶凝胶法制备了WO3溶胶, 并结合提拉镀膜法, 分别在普通玻璃载玻片和抛光硅片上制备了掺钯气致变色WO3纳米结构薄膜; 并分别在50, 150, 250, 350和450 ℃的空气氛围中对薄膜进行了热处理. 采用IR、双椭圆偏振光谱仪、AFM和XRD分析了薄膜的性质和微观结构, 观察了薄膜的表面形貌, 根据所得数据讨论了不同热处理温度对薄膜的结构和气致变色性能的影响.     

制备条件对铝掺杂氧化锌(AZO)薄膜结构和电学性质的影响

本文利用溶胶-凝胶法在玻璃基底上制备得到了AZO透明导电薄膜,就两种不同的热处理-退火方式对薄膜的结构与性质的影响做了比较,研究了掺杂浓度、退火温度对薄膜结构及性质的影响规律.结果表明,高温、分层退火、铝掺杂均有利于生成结晶度高、具有C轴优先取向的AZO薄膜;高温和分层退火有利于晶粒长大,相反铝掺杂却有碍晶粒长大;薄膜的电学性质随退火温度和铝掺杂量的变化呈现规律的变化.通过分析AZO薄膜内的晶体生长过程,本文认为主要是制备条件和AZO晶体的晶面习性导致了薄膜的结晶度、晶体生长取向性和晶粒尺寸等方面的差异.     

二氧化钛/聚乙烯吡咯烷酮纳米复合薄膜的制备与表征

采用溶胶-凝胶法(so1 gel)制备了TiO2/聚乙烯吡咯烷酮(PVP)有机 无机纳米复合薄膜.采用扫描电子显微镜、接触角测定仪、红外光谱仪、紫外 可见吸收光谱仪和静 动摩擦系数测定仪对所制备的TiO2/PVP纳米复合薄膜进行了结构表征和性能研究.结果表明:所制备的TiO2/PVP纳米复合薄膜表面平整光滑、无裂纹、具有一定的疏水性、良好的透明性、防紫外线性能和减摩抗磨性能.     

溶胶-凝胶工艺制备发光薄膜研究进展

本文综述了通过深胶－凝胶工艺制备发光薄膜的基本过程、薄膜的表征方法、发光薄膜的当前发展及应用情况。依据组成特点,对溶胶－凝胶法制备的发光薄膜乾地了分类阐述,并预言了今后该法制备发光薄膜的发展趋势。     

Preparation of TiO2 Thin Film Photocatalysts by Dip Coating Using a Highly Viscous Solvent

TiO₂ thin film photocatalysts coated onto soda lime glass were prepared by a dip coating process using a highly viscous solvent. The source of the TiO₂ was tetraisopropyl orthotitanate, and -terpineol was used as the solvent. Two types of thin film preparation procedures based on dip coating (a sol-gel system and thermal decomposition system) were used to prepare the samples. TiO₂ thin films were obtained after calcination at 450°C for 1 hour. The film thickness obtained with a single dipping was proportional to the viscosity of the dip coating solutions. The obtained thin films were transparent with a thickness of 1 m. The crystal form of the obtained photocatalyst films was anatase alone. The thin films were formed with aggregated nano-sized TiO₂ single crystals (7–15 nm). The photocatalytic activity of the TiO₂ thin films, as evaluated by the photooxidation of NO (1 ppm) in dry air, was as high as our previous TiO₂ thin films prepared by the sol-gel method.     

Structure and morphology of nanostructured zinc oxide thin films Prepared by dip-vs. spin-coating methods

In this study, we use dipping and spinning methods to coat glass slides with sol-gel ZnO thin films, composed of zinc acetate dihydrate, monoethanolamine (MEA), de-ionized water and isopropanol. The effect of the annealing temperature on the structural morphology and optical properties of these films is investigated. These ZnO films were preheated at 275 °C for 10 min and annealed either at 350, 450 or 550 °C for 60 min. As-deposited films, formed by amorphous zinc oxide-acetate submicron particles, are transformed into a highly-oriented ZnO after thermal treatment. The surface morphology, phase structure and optical properties of the thin films were investigated by scanning electron microscopy, X-ray diffraction (XRD) and optical transmittance. Both techniques produced nanostructured ZnO thin films with well-defined orientation. The annealed films were transparent in the visible range with an absorption edge at about 375 nm and a transmittance of ca 85–90% with an average diameter of 40 nm. XRD results show the film was composed of polycrystalline wurtzite, with a preferential c-axis orientation of (002) and a single sharp XRD peak at 34.40, corresponding to the hexagonal ZnO. The grain size is increased by the annealing temperature. Both coating techniques create sol-gel ZnO films with the potential for application as transparent electrodes in optic and electronic devices.     

Structure and photochromic properties of molybdenumphosphoric acid/TiO<Subscript>2</Subscript> composite films

TiO₂ sol-gel composite films with dropping molybdenumphosphoric acid (PMoA) have been prepared by sol-gel method. The structure and constitute of composite thin films were studied with Fourier transforms infrared spectroscopy (FT-IR) atomic force microscopy (AFM), and X-ray diffraction (XRD) patterns, respectively. The photochromic behavior and mechanism of composite thin films were investigated with ultraviolet-visible spectra (UV-vis) and electron spin resonance (ESR). FT-IR results showed that the Keggin geometry of PMoA was still preserved inside PMoA/TiO₂ composite thin films, and a charge transfer bridge was built at the interface of PMoA and TiO₂ through the Mo-O-Ti bond. Surface topography of the composite film showed obvious changes before/after adding PMoA, and the surface topography of composite films showed obvious changes before/after irradiating as well. Composite thin film had reversible photochromic properties. Irradiated with UV light, transparent films changed from colorless to blue and they can bleach completely with ambient air in the dark. ESR results showed that TiO₂ were excitated by UV light to produce electrons, which deoxidized PMoA to produce heteropolyblues. The photochromic process of PMoA/TiO₂ system was carried through electron transfer mechanism.     

Synthesis of Transparent Mesoporous and Mesostructured Thin Silica Films

A novel method for obtaining crack-free transparent periodic mesoporous thin films is described. Such films are prepared by a simple sol-gel process using surfactants as templates, with a pre-treatment of the glass substrate. The silicate precursor (tetraethoxysilane) is pre-hydrolyzed under acidic conditions before dissolving directly cetyltrimethylammonium bromide (CTAB). The solution is then spin-coated on pre-treated glass substrate. After the film has been deposited, it is calcined in air. X-ray Diffraction (XRD) has been used to characterize the film before and after thermal treatment. The film consists of a nanocomposite material with a periodic structure. Before calcination the XRD pattern has a sharp peak at d = 3.8 nms which is broadened and shifted by about 3.0 nm after calcination. Infrared transmission spectra have been performed on the films. Analysis of the free OH group stretching vibration indicates the removal of the surfactant after calcination in addition to an enhancement of the specific surface area.     

Anatase TiO2 porous thin films prepared by sol-gel method using CTAB surfactant

Anatase TiO₂ porous thin films were prepared on glass substrates by sol-gel method with Cetyltrimethylammonium Bromide (CTAB) as a pore-forming agent, Tetrabutylorthotitanate as Ti precursor, ethanol as solvent and diethanolamine as chelating agent respectively. IR, TG-DSC, XRD and SEM analyzed the chemical and physical changes during sol-gel process and characteristics of the films. Effects of the amount of CTAB, alkane and water on morphology of the films were discussed and the principle of forming porous structure was proposed. It was shown that the diameter of pores was changed in the range of 30–400 nm.     

Creation of high-refractive-index amorphous titanium oxide thin films from low-fractal-dimension polymeric precursors synthesized by a sol-gel technique with a hydrazine monohydrochloride catalyst

Amorphous titanium dioxide (TiO(2)) thin films exhibiting high refractive indices (n ≈ 2.1) and high transparency were fabricated by spin-coating titanium oxide liquid precursors having a weakly branched polymeric structure. The precursor solution was prepared from titanium tetra-n-butoxide (TTBO) via the catalytic sol-gel process with hydrazine monohydrochloride used as a salt catalyst, which serves as a conjugate acid-base pair catalyst. Our unique catalytic sol-gel technique accelerated the overall polycondensation reaction of partially hydrolyzed alkoxides, which facilitated the formation of liner polymer-like titanium oxide aggregates having a low fractal dimension of ca. (5)/(3), known as a characteristic of the so-called "expanded polymer chain". Such linear polymeric features are essential to the production of highly dense amorphous TiO(2) thin films; mutual interpenetration of the linear polymeric aggregates avoided the creation of void space that is often generated by the densification of high-fractal-dimension (particle-like) aggregates produced in a conventional sol-gel process. The mesh size of the titanium oxide polymers can be tuned either by water concentration or the reaction time, and the smaller mesh size in the liquid precursor led to a higher n value of the solid thin film, thanks to its higher local electron density. The reaction that required no addition of organic ligand to stabilize titanium alkoxides was advantageous to overcoming issues from organic residues such as coloration. The dense amorphous film structure suppressed light scattering loss owing to its extremely smooth surface and the absence of inhomogeneous grains or particles. Furthermore, the fabrication can be accomplished at a low heating temperature of <80 °C. Indeed, we successfully obtained a transparent film with a high refractive index of n = 2.064 (at λ = 633 nm) on a low-heat-resistance plastic, poly(methyl methacrylate), at 60 °C. The result offers an efficient route to high-refractive-index amorphous TiO(2) films as well as base materials for a wider range of applications.     

Low Temperature Sol-Gel Preparation of Nanocrystalline TiO2 Thin Films

TiO₂ nanocrystalline thin films with varying degree of porosity have been prepared using a low temperature method. TiO₂ films of the anatase form have been obtained by using a polyethylene glycol (PEG) modified sol-gel method. Densification and crystallization of the films was found to result from the thermal treatment of the dip coated films in boiling water. The films have been characterized by Raman, XRD, FTIR, AFM and optical methods. Highly transparent films with transmission in excess of 85% and porosity as high as 58% are formed predominantly of anatase crystallites of dimensions of the order of 5 nm. Initial results on lithium intercalation into these films resulting in an efficient optical modulation in the visible and near infrared regions demonstrate a good potential of these films for electrochromic applications.     

醋酸处理对TiO_2纳米薄膜光催化性能的影响

用溶胶－凝胶方法在普通玻璃基体上制备了均匀透明的TiO_2纳米薄膜，并经 500℃煅烧2h，煅烧后的TiO_2薄膜在2 mol·L~(-1)的CH_3COOH水溶液中处理24h， 最后分别在100和500℃进行第二次热处理，醋酸处理前后的薄膜分别用UV－vis, SEM, XRD和XPS进行了表征，并用甲基橙水溶液的光催化降解评价TiO_2纳米薄膜 的光催化性能，结果发现：用醋酸处理后的TiO_2纳米薄膜的光催化活性高于处理 前薄膜的的光催化活性；而且，酸处理后经500℃热处理的TiO_2纳米薄膜的光催化 活性明显高于经100℃热处理的TiO_2纳米薄膜的光催化活性。     

Preparation and spectroscopic studies of sol-gel derived GeO2/organically modified silane hybrid materials for optical waveguides

GeO₂/organically modified silane organic-inorganic hybrid materials derived by a sol-gel technique were studied for optical waveguide applications. Acid-catalyzed solutions, firstly, γ-glycidoxypropyltrimetho-xysilane mixed with germanium isopropoxide, and secondly, methyltrimethoxysilane mixed with germanium isopropoxide were used as precursors. Optical and structural properties of the waveguide thin films prepared from the two types of sols were characterized by using the prism coupling technique, atomic force microscopy, thermal gravimetric analysis, UV-visible spectroscopy, and Fourier transform infrared. The obtained results indicate that in both cases, crack-free and highly transparent waveguide thin films with a thickness of more than 2-μm could be obtained by a single spin-coating process and at a low-temperature heat treatment of 100°C. A strong UV absorption region at short wavelength ∼200 nm, accompanied with a shoulder peaked at ∼240 nm, was also identified. It has been experimentally demonstrated that a channel waveguide structure could easily be fabricated from the hybrid sol-gel thin films by using reactive ion etching.     

Fe_2O_3掺杂TiO_2薄膜对甲基紫溶液光催化降解

甲基紫是一种相当稳定的有机物 ,能被 Ti O2 光催化降解 .本文采用 sol-gel工艺在玻璃表面制得了均匀透明的 Ti O2 薄膜 ,研究了热处理温度、涂覆层数、掺杂 Fe2 O3 等制备工艺 ,以及溶液 p H值和助催化剂H2 O2 等因素对 Ti O2 薄膜的光催化性能和稳定性的影响 .结果表明 ,掺 Fe2 O3 的 Ti O2 薄膜对甲基紫的降解率明显优于未掺 Fe2 O3 的 Ti O2 薄膜 .