Preparation and Properties of Anti-Reflection/Anti-Static Thin Films for Cathode Ray Tubes Prepared by Sol-Gel Method Using Photoirradiation

A new technique for preparing anti-reflection/anti-static thin films for CRTs at low temperature has been developed. Double-layered films of SiO₂/SnO₂ were formed on a CRT panel surface by the sol-gel method using photoirradiation. The new method makes it possible to reduce heat treatment temperature (°C) by almost 50% and treatment time to approximately 33% of the conventional levels.     

Tribological properties of ormosil coatings

Transparent plastics are not scratch resistant. The damage leads to a loss of optical properties. Coatings prepared using either tetraethoxysilane or colloidal silica particles embedded in glymo is a way to avoid these disadvantages. Tribological experiments are carried out to better understand the surface modification due to a sliding friction. It is shown that the wear track is not directly related to usual mechanical properties such as Young's modulus and the hardness of the coating. The different stages leading to material loss are discussed in term of particle removal and debris circulation (accumulation or elimination) through the friction track. The mechanical properties of the film combined with the film to substrate adhesion are expected to play an important role as it can be deduced from results obtained as a function of the coating composition.     

A study on the utility of bismuth-film electrodes for the determination of In(III) in the presence of Pb(II) and Cd(II) by square wave anodic stripping voltammetry

This work is an investigation into the utility of bismuth-film electrodes (BiFEs) for the determination of indium in the presence of cadmium and lead by square wave anodic stripping voltammetry (SWASV). The purpose of this study was to demonstrate that, after judicious choice of the associated chemical and instrumental conditions, it is possible to achieve satisfactory separation of the relevant stripping peak and, thus, to determine simultaneously trace concentrations of cadmium, lead and indium. It was conclusively demonstrated that a BiFE performed better than the equivalent mercury-film electrode (MFE) in this particular application.     

氧化钨薄膜微型电化学器件的研究

本文论述了WO_3薄膜氢离子敏器件的结构、原理、制备技术和测试分析。利用WO_3薄膜在H+溶液中由绝缘转化为导电特性,成功地研制成氢离子敏器件。这是一种简易而经济的微型pH敏器件技术。     

酞菁锰-表面活性剂薄膜电极的电化学表征及其对三氯乙酸的电化学催化作用的研究

将酞菁锰（ＭｎＰｃ）掺入阳离子表面活性剂双十二烷基二甲基溴化铵（ＤＤＡＢ）的氯仿溶液，并涂布于热解石墨电极表面，待氯仿挥发后即制得ＭｎＰｃ－ＤＤＡＢ薄膜电极。循环伏安实验表明，在ＫＢｒ溶液中，该薄膜电极有两对还原氧化峰，第一对峰的Ｅｐｃ１＝－０．２７Ｖ，Ｅｐａ１＝０．０１Ｖ；第二对峰的Ｅｐｃ２＝－０．７６Ｖ，Ｅｐａ２＝－０．６２Ｖ（ｖｓ．ＳＣＥ）。本文着重探讨了第二对峰的电化学行为，估计了该体系的电荷传递扩散系数Ｄｃｔ和表观非均相电极反应速率常数Ｋ０′等电化学参数，并可将该薄膜电极用于催化三氯乙酸的电化学还原。     

吲哚衍生物与花生酸混合LB膜的制备及结构研究

本文将3-三氰基乙烯基-N-十六烷基吲哚与花生酸混合制成单分子膜。不同摩尔比混合膜的π-A曲线均出现平台,表明膜压缩过程中分子排列相态发生变化。混合LB膜的紫外吸收光谱证明吲哚分子形成聚集体,X-射线衍射结果说明这种聚集体被夹带在花生酸的框架结构中。     

Y2O3薄膜处理对3Cr25Ni7N合金的抗高温氧化性能的影响

采用电沉积-热解法在3Cr25Ni7N合金表面制备了Y2O3薄膜,并研究了薄膜处理对合金在1000℃空气中的抗高温氧化性能的影响。氧化动力学曲线、SEM及XRD分析结果表明,Y2O3薄膜处理使合金表面氧化膜以尖晶石结构为主,氧化膜致密,有效地抑制了Cr2O3的挥发反应,且氧化膜与基体的附着性好,因此合金在高温下的抗氧化性能得到提高,这与氧化钇薄膜在较低温度下抗高温氧化性能提高的机制是不同的。在不同温度下,Y2O3薄膜处理均可以有效提高合金的抗高温氧化性能。     

Visible Up-Conversion Luminescence in Ho3+: BaTiO3 Nano-Crystals Prepared by Sol Gel Technique

Visible up-conversion emissions at (435, 545, 580, 675 and 690 nm) and (437, 547 575 and 675 nm) have been observed from the sol-gel derived nano-crystalline Ho³⁺: BaTiO₃ powders and thin films respectively, under 808 nm laser diode excitation emissions. Combined with the energy level structure of Ho³⁺ ions and the kinetics of the visible emissions, the up-conversion mechanism has been analyzed and explained. The blue, green and red emissions of both samples has been attributed to the ground state-directed transition from (⁵F₁), (⁵S₂) and (⁵F₅), which are populated through excited state absorption (ESA) for 808 nm excitation. Nano-structure pure barium titanate and doped with different concentrations of Ho³⁺ ions in the from of powder and thin film have been prepared by sol-gel technique, using barium acetate (Ba(Ac)₂), and titanium butoxide (Ti(C₄H₉O)₄), as precursors. The thin films were prepared by sol-gel spin coating method. The as-grown thin films and powders were found to be amorphous, which crystallized to the tetragonal phase after heating at 750°C in air for 30 minutes. The crystallite sizes of the thin film and powder both doped with 4% Ho³⁺ ions was found to be equal to 11 and 16 nm, respectvely.     

Fine Structure of Meniscus of a Wetting Liquid

Equilibrium of a capillary meniscus near a wetting film on a solid in a gravitational field is considered. Unlike previous studies, the present study proves that the fine meniscus structure in a gravitational field is a universal feature—it takes place in a wide variety of problems. In the general case, the capillary meniscus is at a certain distance from the wetting film and does not intersect it. The relation for the minimum distance from the arbitrary meniscus to the solid generalizes the Derjaguin formula for a flat slit. An equation that optimally approximates the meniscus with due account of the contribution of the meniscus/film transition region is derived. A refined solution to the problem of a meniscus on a vertical plate is derived within the perturbation theory. Both gravity and nonuniformity of the vertical static film above a capillary–gravitational meniscus do not affect the minimum distance (the influence is less than 0.0001). A general method for solving sophisticated problems of capillary equilibrium in gravitational field is proposed.     

Infrared Evidence for Hoffman Reaction During Calcination of Surfactant-Templated Silica Films and Analysis of the Resulting Surface Sites

Fourier Transform Infrared transmission spectroscopy is used to characterize surfactant-templated silica films on glass. The calcination process is followed in situ and evidence for the removal of the surfactant along the Hoffman reaction is given. Once calcined, the surface of the pores of the mesoporous films is proven by deuteration experiment to be hydroxylated. Bands are attributed to isolated and hydrogen-bonded silanols. Silylation reaction with hexamethyldisilazane only occurs with isolated silanol groups.