Annealing Temperature dependence of Photoluminescence from Silicon-rich silica Films

The silicon-rich silica films were prepared by a dual-ion-beam co-sputtering method from a composite Target in an argon atmosphere. The structure of the films studied by the aid of TEM and XRD is amorphous. The photoluminescence (PL) spectra were found to have a 4- luminescent band peak at 320 nm, 410 nm, 560 nm, and 630 nm, respectively, at room temperature. The intensity and the wavelength position of PL are dependent on annealing temperature (Ta), and the luminescent mechanism is analyzed.

Helium Plasma Damage of Low-k Carbon Doped Silica Film:the Effect of Si Dangling Bonds on the Dielectric Constant

The low-k carbon doped silica film has been modified by radio frequency helium plasma at 5 Pa pressure and 80 W power with subsequent XPS, FTIR and optical emission spec- troscopy analysis. XPS data indicate that helium ions have broken Si-C bonds, leading to Si-C scission with C（1s） lost seriously. The Si（2p）, O（ls）, peak obviously shifted to higher binding en- ergies, indicating an increasingly oxidized Si（2p）. FTIR data also show that the silanol formation increased with longer exposure time up to a week. Contrarily, the CHa stretch, Si-C stretching bond and the ratio of the Si-O-Si cage and Si-O-Si network peak sharply decreased upon exposure to helium plasma. The OES result indicates that monovalent helium ions in plasma play a key role in damaging carbon doped silica film. So it can be concluded that the monovalent helium ions besides VUV photons can break the weak Si-C bonds to create Si dangling bonds and free methyl radicals, and the latter easily reacts with O_2 from the atmosphere to generate CO_2 and H_2O. The bonds change is due to the Si dangling bonds combining with H_2O, thereby, increasing the dielectric constant k value.

Preparation of Scratch-Resistant Nano-Porous Silica Films Derived by Sol-Gel Process and Their Anti-reflective Properties

Structural strengthening of the nano porous silica films has been reported. The films were prepared with a base/acid two-step catalyzed TEOS-based sol-gel processing and dip-coating, and then baked in the mixed gas of ammonia and water vapor. The silica films were characterized with TEM, AFM, FTIR, spectrophotometer, ellipsometer, and abrasion test, respectively. The experimental results have shown that the films have a nanostructure with a low refractive index and can form an excellent scratch-resistant broadband anti-reflectance. The two-step catalysis noticeably strengthens the films, and the mixed gas treatment further improves mechanical strength of the silica network. Finally the strengthening mechanism has been discussed.

FABRICATION AND CHARACTERATION OF NANOPOROUS SILICA FILM

Colloidal silica sol is formed by a novel hydrolyzing procedure of tetraethyl orthosilicate(TEOS) catalyzing with NH 3 ·H 2 O in aqueous mediums. Glycerol, combining with the hydrolyzed intermediates of TEOS, controls growing of the silica particles; poly(vinyl vinyl alcohol makes the colloidal silica sol with polymeric structure and spinning, thermal strain makes the gel silica film changed into a nanoporous structure with diameter ranging 50-150 nm. Morphologies of the nanoporous silica film have been characterized; the porosities (%) is 32-64; the average dielectric constant at 1MHz region is 2.0 and 2.1; the thermal conductivity is less than 0.8. Chemical mechanism of the sol gel process is discussed.

A novel fabrication of meso-porous silica film by sol-gol of TEOS

A homogeneous crack-free nano- or meso-porous silica films on silicon was fabricated by colloidal silica sol derived by hydrolyzing tetraethyl orthosilicate (TEOS) catalyzing with (C4H9)4N^+OH^- in water medium. The solution with ratio of H2O/TEOS≥15,R4N^+ and glycerol as templates,combining with the hydrolyzed intermediate,controlled the silica aggregating; the templated silica film with heterostructure was developed into homogeneous nano-porous then meso-porous silica films after being annealed from 750℃ to 850℃;the formation mechanism of the porous silica films was discussed;morphologies of the silica films were characterized. The refractive indexes of the porous silica films were 1.256-1.458,the thermal conductivity <0.7 W/m/K.The fabricating procedure and the sequence had not been reported before.

Microstructure Control of Nanoporous Silica Thin Film Prepared by Sol-gel Process

Nanoporous silica films were prepared by sol-gel process with base, acid and base/acid two-step catalysis.Transmission electron microscope （TEM） and particle size analyzer were used to characterize the microstructure and the particle size distribution of the sols. Scanning electron microscopy （SEM）, atomic force microscopy （AFM） and spectroscopic ellipsometer were used to characterize the surface microstructure and the optical properties of the silica films. Stability of the sols during long-term storage was investigated. Moreover,the dispersion relation of the optical constants of the silica films, and the control of the microstructure and properties of the films by changing the catalysis conditions during sol-gel process were also discussed.

Solution-processable precursor route for fabricating ultrathin silica film for high performance and low voltage organic transistors

Silica is one of the most commonly used materials for dielectric layer in organic thin-film transistors due to its excellent stability, excellent electrical properties, mature preparation process, and good compatibility with organic semiconductors. However, most of conventional preparation methods for silica film are generally performed at high temperature and/or high vacuum. In this paper, we introduce a simple solution spin-coating method to fabricate silica thin film from precursor route, which possesses a low leakage current, high capacitance, and low surface roughness. The silica thin film can be produced in the condition of low temperature and atmospheric environment. To meet various demands, the thickness of film can be adjusted by means of preparation conditions such as the speed of spin-coating and the concentration of solution. The p-type and n-type organic field effect transistors fabricated by using this film as gate electrodes exhibit excellent electrical performance including low voltage and high performance. This method shows great potential for industrialization owing to its characteristic of low consumption and energy saving, time-saving and easy to operate.

Polymer-free electrospun separator film comprising silica nanofibers and alumina nanoparticles for Li-ion full cell

A separator film for high-performance Li-ion batteries was prepared by electrospinning. The film had a hybrid morphology of silica nanofibers(SNFs) and alumina nanoparticles(ANPs), with a smooth surface, polymer-free composition, high porosity(79%), high electrolyte uptake(876%), and excellent thermal stability. Contact angle measurements demonstrated the better immersion capability of the SNF-ANP separator film for commercial liquid electrolytes than a commercial CELGARD 2500 separator film. Moreover,compared to the commercial CELGARD 2500 separator, the ionic conductivity of the SNF-ANP separator film was nearly three times higher, the bulk resistance was lower at elevated temperature(120 ℃), the interfacial resistance with lithium metal was lower, and the electrochemical window was wider. Full cells were fabricated to determine the cell performance at room temperature. The specific capacity of the full cell with the SNF-ANP separator film was 165 mAh g-1;the cell was stable for 100 charge/discharge cycles and exhibited a capacity retention of 99.9%. Notably, the electrospun SNF-ANP separator film can be safely used in Li-ion or Li-S rechargeable batteries.

Provitamin D Doped Silica and Polymeric Films: New Materials for UV Biosensor

The original technologies of growing silica films, impregnated with 7-dehydrocholesterol (provitamin D3) on quartz substrates and free transparent films on the basis of polyvinyl alcohol and polyvinyl butyral have been developed. Provitamin D photoisomerization in the films under UVB irradiation was investigated by UV absorption spectroscopy. Remarkable changes in the absorption spectrum of 7-DHC were observed in silica and polyvinyl alcohol films as com-pared with ethanol solution, only in polyvinyl butyral film the spectrum was very nearly, while the spectral kinetics of 7-DHC photoisomerization in all the films was different from ethanol. We suggest that several films have potential as UV dosimeters to measure accumulated ‘antirachitic’ UV dose in the same manner as erythemic UV dose is measured by commonly used polysulphone film.

Low Temperature Coating of Anatase Thin Films on Silica Glass Fibers by Liquid Phase Deposition

Uniform crystalline TiO2 thin films were coated on silica glass fibers by liquid phase deposition from aqueous solution of ammonium hexafluorotitanate at low temperature. TiO2 thin films and nanopowders were prepared by adding H3BO3 into （NH4）2TiF6 solution supersaturated with anatase nano-crystalline TiO2 at 40 ℃. The effects of the deposition conditions on the surface morphology, section morphology, thickness of the deposited TiO2 thin films were investigated. The results indicate that the growth rate and particle size of the thin films were controlled by both the deposition conditions and the amount of anatase nano-crystalline TiO2.

Uniform hierarchical silica film with perpendicular macroporous channels and accessible ordered mesopores for biomolecule separation

Herein, we demonstrate that silica films with perpendicular macroporous channels and accessible ordered mesopores can be conveniently prepared. The hierarchical macroporous–mesoporous silica films are synthesized by using zinc oxide nanorod array as macroporous template and CTAB surfactant as mesoporous template. In basic surfactant-containing solution, ordered mesoporous silica shells homogeneously grow on the zinc oxide nanorod array. The growth of the mesostructures do not require any chemical modification for the zinc oxide nanorod, which opens a new way for preparing hierarchical silica films with perpendicular mesochannels. The prepared hierarchical macroporous–mesoporous silica films possess a uniform thickness of 2μm, large perpendicular macropores with a length of 1.8μm and a width of 80 nm, and accessible ordered mesopores. Separation experiment demonstrates that this macroporous–mesoporous film can effectively separate biomolecules with different sizes.

白炭黑补强天然胶乳胶膜性能的提升研究

采用白炭黑对天然胶乳胶膜补强,并通过正交试验研究硫黄、促进剂PX、碳酸锌、白炭黑用量对硫化胶膜物理性能的影响。结果表明:以硫化胶膜的拉伸强度为考察指标,4个因子的影响从大到小依次为促进剂PX、白炭黑、碳酸锌、硫黄,优化用量为促进剂PX0.9份、白炭黑1.11份、碳酸锌0.6份、硫黄1份,相应配方硫化胶膜的拉伸强度可达到31.37 MPa;以硫化胶膜的撕裂强度为考察指标,4个因子的影响从大到小依次为白炭黑、促进剂PX、硫黄、碳酸锌,优化用量为白炭黑1.31份、促进剂PX0.7份、硫黄1.25份、碳酸锌0.5份,相应配方硫化胶膜的撕裂强度可达到65 kN·m^(-1)。

The Structure and Emission Properties of SiO_2 Nanometer Film Containing Ag

Colloidal silver particles are formed on float glass by heat treatment with coated silica film containing Ag by sol-gel process . The Sn2+ on surface of float glass influences the formation of colloidal Ag particles . The microstructure of the film and the granularity of silver particles were studied by TEM and HEED. The emission property of the samples was measured. The results show that aggregation of metal particles degrades emission intensity , and that content of Ag, withdrawing speed and heat treatment temperature of samples has a greater effect on photoluminescence.

二氧化硅含量对亚光聚酯薄膜性能影响研究

采用超有光聚酯和亚光聚酯,经过共混、熔融挤出、双向拉伸等方式制备了不同二氧化硅含量的亚光薄膜,采用差示扫描量热仪(DSC)研究了不同样品厚片的热性能,计算了相应的结晶性能参数;利用双向拉伸试验机在亚光薄膜制备过程中对比了不同样品拉伸过程中的拉力-拉伸倍率曲线;采用透射雾度仪、激光共聚焦显微镜等仪器分析了不同二氧化硅含量亚光薄膜的光学性能、微观形貌和表面粗糙度。结果表明,随着二氧化硅含量的增加,相应亚光聚酯样品的T c逐渐降低,熔融结晶Avrami指数n呈现升高趋势,半结晶期t_(1/2)则呈现降低的趋势。随着亚光聚酯样品中二氧化硅含量的增加,相同加工条件下其拉力呈现上升的趋势,而且拉伸倍率越高差异越大。二氧化硅含量对于亚光薄膜的光泽度影响最大,雾度影响次之,透过率影响最小;二氧化硅会引起薄膜粗糙度发生较大的变化,随着二氧化硅含量的增加,粗糙度先增大后减小,然后趋于稳定,薄膜表面趋于平整化。

改性硅胶作为PAO-10润滑添加剂摩擦学性能研究

目的合成4种改性硅胶,并将其作为PAO-10的润滑油添加剂,考察其摩擦学性能,并对润滑机理进行分析。方法采用棕榈酰氯对不同目数的普通硅胶进行改性,形成长烃链酰胺官能团,并通过傅里叶红外光谱仪对其结构进行确认。进一步通过摩擦磨损试验机和三维轮廓仪对润滑体系的摩擦学性能进行表征,采用接触角、扫描电子显微镜(SEM)、能谱仪(EDS)和X射线光电子能谱(XPS)对润滑机理进行研究。结果该系列改性硅胶添加剂极大改善了PAO-10的摩擦学性能。当向PAO-10中添加1.0%的改性硅胶S_(200~300)PMAD后,PAO-10的摩擦系数降低了60%,磨损体积降低了74%。结论摩擦副表面形成一定厚度的物理吸附膜层和含Fe_(2)O_(3)的化学反应膜层,二者共同提升了润滑体系的摩擦学性能,改性硅胶上附着的烷基链和活性杂原子是形成该保护膜的重要原因。

Polymeric Liquid Templating of Hierarchical Porous Films by Nanofibrillar Alginic Acid Assemblies

Hierarchical phases of the biomaterials can be used as template to transfer their intricate organization into biomimic inorganic solids. Herein, hierarchical mesoporous silica films with aligned pores have been templated by nanofibrillar alginic acid. An aqueous suspension of the alginic acid nanofibers was prepared by treating the brown seaweeds with sodium carbonate solution and subsequent precipitation in dilute hydrochloric acid. The alginic acid nanofibers of the organize into a hierarchical aligned phase in an acetic acid-sodium acetate buffer that was used to template silica-alginic acid composite films by evaporation induced self-assembly of alkoxysilane with nanofibrillar alginic acid. Calcination of the alginic acid template afforded hierarchical mesoporous silica glasses. Carbonization of the silica-alginic acid composites and subsequent etching the silica recovered mesoporous carbon supercapacitors.

Fabrication of Au/SiO_(2) Nanocomposite Films by Self-Assembly Multilayer Method

Gold colloid was prepared by chemical reduction of hydrogen tetrachloroaurate, polyelectrolyte/gold nanoparticle/silica nanoparticie composite films were fabricated via an electrostatic self-assembly multilayer method, and composite films of gold nanoparticle dispersed in silica matrix were formed by heat-treating the polyelectrolyte/gold nanoparticle/silica nanoparticle composite films to eliminate the polyelectrolyte. The obtained composite films were investigated with UV-vis, TEM, AFM and XRD. The results show that the self-assembly multilayer method is a promising process to produce composite films of gold nanoparticle-dispersed in organic and/or inorganic matrixes.

Heat-Resistant Properties of a SiO₂-Coated PET Film Prepared by Irradiating a Polysilazane-Coated Film with Excimer Light

Flexible electronics have been recently paid much attention. A flexible substrate (Organic resin film) is indispensable component for flexible devices. Though PET film is low-cost organic film, low heat-resistance of PET film limits its application as a flexible device substrate. We have developed heat-resistant PET which does not deteriorate even at 190&deg;C heat treatment for one hour. An excimer light was irradiated onto a polysi-lazane (PHPS: perhydropolysilane)-coated film to form a dense silicon-dioxide (SiO2) layer on a PET film, and the heat-resistance property of the formed film was examined. Changes of surface state and cross-sectional structure of the formed film due to heat treatment were investigated by scanning electron microscope (SEM) and transmission electron microscope (TEM). Compared to normal PET, which is deteriorated and whitened by heat treatment of about 110&deg;C - 120&deg;C, the SiO2-coated PET film maintains transparency and does not deteriorate after heat treatment at 180&deg;C - 190&deg;C for one hour. This high heat resistance is due to a dense SiO2 film formed on the surface that prevents surface precipitation and crystallization of low-molecular-weight oligomers (which are the cause of thermal degradation of PET). It is expected that enhancing the heat resistance of PET—which has high versatility and low cost—to about 180&deg;C to 190&deg;C will allow SiO2-film-coated PET to be developed as a film substrate for flexible devices.

封口处理对保存在silica膜上的人全血DNA质量的影响

目的:探索一种可延长室温下人全血DNA保存时间的方法。方法:分为封口膜和无封口膜两组,每组样品分别在室温保存第0 d、6 d、10 d、14 d、18 d、20 d、22 d及24 d时测定浓度、完整性及剩余体积。结果:随着时间延长,保存在silica膜上的DNA随体积的减少浓度上升,DNA纯度变化则不明显,DNA在第10 d出现降解现象,第24 d降解严重。无封口膜组于第20 d剩余体积低于检测要求最低值,封口膜组于第24 d剩余体积低于检测要求最低值。结论:保存在silica膜上的DNA可室温保存至少24 d。