TiO_2-SiO_2-GeO_2凝胶玻璃涂膜的制备及其光学性能研究

以四氯化锗、正硅酸乙酯、钛酸丁酯为原料 ,采用溶胶 -凝胶法制备了TiO2 -SiO2 -GeO2涂膜。利用DTA、TG、XRD研究了TiO2 -SiO2 -GeO2 凝胶向玻璃的转化。利用XPS研究了TiO2 -SiO2 GeO2 体系中Ti、Si、Ge与O原子间的成键情况。测试了涂膜的红外反射率并依据k k关系计算出了折射率。结果表明涂膜中形成了Ti O Si ,Ge O Si和Ti O Ge键结构 ,该涂膜在 9～ 11μm波长范围存在红外反射窗口 ,在CO2 激光波长附近折射率小于 1,存在反常色散现象 ,适合作空芯波导材料     

TiO2—SiO2—GeO2凝胶玻璃涂膜的制备及其光学性能研究

以四氯化锗、正硅酸乙酯、钛酸丁酯为原料,采用溶胶－凝胶法制备了TiO2-SiO2-GeO2涂膜。利用DTA、TG、XRD研究了TiO2-SiO2-GeO2凝胶向玻璃的转化。利用XPS研究了TiO2-SiO2-GeO2体系中Ti、Si、Ge与O原子间的成键情况。测试了涂膜的红外反射率并依据k-k关系计算出了折射率。结果表明涂膜中形成Ti-O-Si,Ge-O-Si键结构,该涂膜在9－11μm波长范围存在红外反射窗口,在CO2激光波长附近折射率小于1,存在反常色散现象,适合作空芯波导材料。     

ZrO2对CaO-Al2O3-SiO2系统微晶玻璃烧结过程的影响研究

CaO-Al2O3-SiO2系统微晶玻璃作为微晶玻璃中的一个新品种,具有非常鲜明的特点.本文讨论了在CaO-Al2O3-SiO2系统微晶玻璃中加入ZrO2,研究了ZrO2对CaO-Al2O3-SiO2系统微晶玻璃烧结的影响.随着ZrO2加入量的增加,玻璃颗粒的烧结收缩率下降,说明ZrO2的加入对玻璃颗粒的烧结收缩有一定的阻碍作用.ZrO2的加入对CaO-Al2O3-SiO2系统微晶玻璃中的主晶相(β-硅灰石晶体)的析出没有大的影响.     

复合晶核剂TiO2/ZrO2对MgO-Al2O3-SiO2系统微晶玻璃的影响研究

本文制备了Mg0-Al2O3-SiO2系微晶玻璃,用XRD、DTA等方法对该系统微晶玻璃材料进行了研究;讨论了复合晶核剂对材料热膨胀性能及热处理温度的影响.结果表明TiO2/ZrO2复合晶核剂中,少量ZrO2(＜0.5wt%)能够降低微晶玻璃材料的热处理温度和热膨胀系数.     

Lu2O3-SiO2体系闪烁体材料研究进展

闪烁体材料是一类吸收X-射线或α,β-射线等高能光子后发出可见光的光功能材料,在高能物理、核医学、地质勘探等领域应用广泛.综述了Lu2O3-SiO2体系闪烁体材料的最新研究进展,包括闪烁晶体、闪烁陶瓷、闪烁粉体和闪烁薄膜的研究现状,并对Lu2O3-SiO2体系闪烁体材料的应用和发展进行了总结.     

掺偶氮苯二氧化钛基复合薄膜的制备及光开关性能

通过低温溶胶-凝胶技术结合旋涂法制备了掺偶氮苯二氧化钛基有机-无机复合薄膜。研究了不同热处理温度对复合薄膜的表面形貌、传输模式、折射率与厚度和光化学结构特性的影响。结果表明:该复合薄膜在低于300℃的热处理温度时表面光滑致密、折射率可调,是良好的光波导材料。通过测试样品在365 nm紫外光和450 nm可见光照射下的吸光度,研究了复合薄膜的光开关性能。在研究周期内,光开关性能良好,具有一定的抗疲劳性,在光电子学领域具有重要的应用价值。     

ZrO2-SiO2复合氧化物的研究进展

ZrO2-SiO2复合氧化物因具有较好的热稳定性和化学稳定性、较大的比表面积和较强的表面酸碱性等优点,已受到广泛关注.本文主要对ZrO2-SiO2复合氧化物的常用制备方法及其影响因素进行了总结,并综述了该复合氧化物在催化反应中的应用.     

固体酸S2O2-8/ZrO2-SiO2催化合成马来酸二辛酯

用S2O8^2-浸渍锆硅复合氧化物，制得固体酸催化剂S2O8^2-／ZrO2-SiO2。用马来酸酐与正辛醇的酯化反应考察了催化剂的活性，并与硫酸、对甲苯磺酸等催化剂的催化效果比较。结果表明：对于给定反应，S2O8^2-对ZrO2-SiO2的促进作用明显高于S24^2-；当n(Zr)：n(Si)为l：6，用硝酸铵作硅酸钠的沉淀剂，用0．7mol/L，的过硫酸铵浸渍12h，在550℃下焙烧3h制得的催化剂S2O8^2-／ZrO2-SiO2具有最高的催化活性，用于催化马来酸酐和正辛醇的酯化反应，可得无色透明的酯化产物，3h内酯化率达98．4％，较S2O8^2-／ZrO2-SiO2催化剂的酯化率提高了约18％．     

Sol-Gel-SPD制备超细Al2O3-SiO2二元粉体材料

以硝酸铝(Al(NO3)3·9H2O)和正硅酸乙酯(TEOS)为原料,采用溶胶-凝胶(Sol-Gel)技术并结合喷雾干燥(SPD)技术制得超细Al2O3-SiO2二元复合粉体材料,并分别于400℃、800℃、1000℃、1150℃和1200℃煅烧2 h;采用全自动比表面积与孔隙率分析仪、TEM、TG-DSC及XRD等仪器研究了热处理温度、pH值(分别为5.5、7和8)以及干燥方法对粉体材料的表面性能、显微形貌、物相组成及Al2O3-SiO2二元系晶体转变过程的影响.结果表明由Sol-Gel-SPD制备的超细Al2O3-SiO2二元粉体材料的比表面积＞448 m2·g-1,而经1200℃煅烧2 h后所得的超细莫来石的比表面积34.05m2·g-1;TG-DSC分析表明采用Sol-Gel-SPD制得的Al2O3-SiO2二元粉体材料的质量损失主要发生在500℃之前;XRD分析表明粉体试样的开始莫来石化温度为1000℃,铝硅尖晶石(6Al2O3·SiO2)与非晶态SiO2在1150～1200℃完全转化为莫来石;比较不同pH值试样经1200℃煅烧后的TEM照片发现,当pH=7时,得到的超细莫来石粉体粒径最小,为50 nm.     

SnO2∶Sb/SiO2复合薄膜的制备与光学性能

采用溶胶-凝胶结合旋涂技术在玻璃基底上制备了SnO2∶Sb/SiO2复合薄膜,利用XRD、FT-IR、SEM、椭偏仪、分光光度计等方法对薄膜样品进行了系统地表征。结果表明:经过热处理后样品生成了SnO2∶Sb和SiO2;薄膜具有双层结构,上层SiO2厚度约105 nm,折射率为1.352,底层SnO2∶Sb厚度约1200 nm,折射率为1.91;优化工艺条件下SnO2∶Sb/SiO2复合薄膜的性能优于SnO2∶Sb薄膜,在相同情况下SnO2∶Sb/SiO2复合薄膜对可见光的透过率大于SnO2∶Sb薄膜,这是因为上层SiO2薄膜折射率较低,与底层高折射率SnO2∶Sb薄膜共同构成减反射膜系,提高了膜系的可见光透过率。相比于单层SnO2∶Sb膜,在可见光部分增透率大于4.5%,近红外波段的增透率小于1.0%,基本保持原有导电膜的低红外辐射特性,并提高了可见光透过率。     

Spectroscopic ellipsometry characterization of TiO2 thin films prepared by the sol–gel method

TiO₂ thin films were prepared on SiO₂/Si(100) substrates by the sol–gel process. XRD results indicate that the major phase of TiO₂ thin films is anatase. The surface morphology and cross-section are observed by FE-SEM. The surface of thin films is dense, free of cracks and flat. The average grain size is about 60–100 nm in diameter. The thickness of single layer TiO₂ thin films is about 60 nm, which increases with the concentration of solution. Ellipsometric angles ψ, Δ are investigated by spectroscopic ellipsometry. The optical constant and the thickness of TiO₂ thin films are fitted according to Cauchy dispersion model. The results reveal that the refractive index and the extinction coefficient of TiO₂ thin films in wavelength above 800 nm are about 2.09–2.20 and 0.026, respectively. The influences of processing conditions on the optical constants and thicknesses of TiO₂ thin films are also discussed.     

Ellipsometric control of the parameters of lead selenide films during oxidation

The changes in the optical characteristics of lead selenide thin films with different degrees of oxidation are investigated using ellipsometry. It is found that, as the degree of oxidation increases, the refractive index, the optical thickness, and the extinction coefficient of lead selenide films decrease monotonically, whereas the effective film thickness increases. The composition of the films can be determined from the measured refractive index at a wavelength λ = 632.8 nm with the use of the dependences calculated on the basis of the single-layer model.     

多孔SiO2膜的制备和增透性能研究

采用溶胶-凝胶结合旋转涂膜法在玻璃基底上制备SiO2薄膜,研究了陈化时间和旋涂速度对SiO2膜增透性能的影响,利用热分析仪、X射线衍射仪、红外光谱仪、扫描电镜、分光光度计、椭偏仪等方法分别对干凝胶的热分解过程、晶体结构、微观形貌、透过率和折射率进行表征.结果表明:膜层透过率与制备条件有一定的规律,随着陈化时间的延长和旋涂速度的增加,增透峰中心波长发生了移动.在最佳工艺条件下,制备的SiO2薄膜具有较好的增透性能,在玻璃上镀SiO2增透膜后,峰值透过率(300～1000 nm)由90％提高到95％,其膜厚为315 nm,折射率为1.352,孔隙率为27％,进一步提高了可见光利用率.     

Responsive plasma polymerized ultrathin nanocomposite films

The plasma polymerization of NIPAAM and titanium isopropoxide monomers into responsive ultrathin films with responsive optical properties using plasma enhanced chemical vapor deposition is reported. The composite ultrathin films possess a large window for potential changes in their refractive index from 1.60 to 1.95. We demonstrated that these polymer films exhibit fast (transition time below 2 s), large, reversible, and repeatable changes to their thickness and refractive index as a function of periodic environmental humidity changes.     

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     

溶胶-凝胶法制备SiO2-TiO2纳米复合薄膜的结构及光学性能研究

采用ｓｏｌ－ｇｅｌ工艺制备了（－ｘ）ＳｉＯ２－ｘＴｉＯ２（ｘ＝５％,８％,２０％,３０％,４０％,５０％摩尔分数）纳米复合薄膜,Ｘ射线衍射及折射率测量表明,随着ＴｉＯ２摩尔分数的增加,薄膜的折射率呈线性增加,而ＴｉＯ２的析晶温度则降低,随着薄膜热处理的提高,其折射率亦增加,主要来自于薄膜结构转变的贡献,即由非晶态转变为锐钛矿相,由锐钛矿转变为金红石与锐钛矿两相共存两转变为完全的金红石相结构,并诱导     

Modified Envelope Method for Obtaining Optical Properties of Weakly Absorbing Thin Films and Its Application to Thin Films of Pb(Zr,Ti)O3 Solid Solutions

A modified envelope method, which includes the consideration of the light intensity loss from the back surface of the substrate, was developed and shown to be a simple and convenient tool for obtaining the optical properties and the thickness of the film by using the transmission spectra alone in the medium and weak absorption regions. In the near-optical band gap region, both the transmission and the reflection spectra were used to calculate the optical constants of the films. This technique was applied to the thin films of PZT solid solutions across the entire composition range. The film thickness derived from the envelope method was cross-checked by a computer simulation method and was found to have an accuracy better than 2%. In addition, the refractive indices were fitted to a simple Sellmeier-type equation for determining the dispersion constants for PZT films. The valid wavelength range of these dispersion relations was from 350 to 2000 nm. The refractive index of the PZT films decreased linearly with increasing zirconium content. On the other hand, the optical band gap energy of the PZT films increased with increasing zirconium content.     

Ellipsometric study of a-C: H films

The optical constants, porosity and thickness of amorphous hydrogenated carbon (a-C: H) films were determined by multiple-angle ellipsometry at an optical wavelength of 632.8 nm. The films were produced by a plasma-activated CVD process in a dc glow discharge of acetylene, toluene and octane. The results indicate that the refractive index of the a-C: H films can be changed over the interval 2.35–1.55 by increasing the deposition rate and an appropriate choice of hydrocarbon precursor. A reduction of the refractive index correlates with a decrease in the extinction index in the range 0.3–0.01. The influence of the chemical nature of the hydrocarbon precursor on optical constants in the visible region is found from the results of the ellipsometric measurements. The variations of the experimental data are reviewed in view of the a-C: H structure model proposed previously. The porosity of the a-C: H films has been determined by a new technique based on the ellipsometric measurements.     

Preparation and properties of photocurable, high refractive, 2-naphthol epoxy-modified urethane acrylate

The back light unit (BLU) is a core component of liquid crystal displays (LCDs) that are used in notebook computers, mobile phones, navigation devices, flat screen TVs, and public information display (PID) devices, among many others. To enhance the optical efficiency of LCDs, optical films with a high refractive index have been used in the BLU. In particular, high refractive chemicals have been the subject of recent investigations to enhance the optical efficiency of BLUs. In this study, we efficiently synthesized photocurable, high refractive 2-naphthol epoxy-modified urethane acrylate (2-NEUA) from 2-naphthol via a three-step reaction. The refractive index of 2-NEUA was higher than that of 2-naphthol epoxy acrylate (2-NEA), presumably because it contains more integrated aromatic rings and therefore has a higher electron density than 2-NEA. Furthermore, we critically evaluated the effects of 2-NEUA on the mechanical properties of UV curable films in this article.     

CO2 laser-assisted preparation of transparent Eu2Ti2O7 thin films

We present a laser-assisted preparation of transparent europium-titanate Eu₂Ti₂O₇ thin films with tailored structural and optical properties. We have evaluated the effects of the irradiation time on the structural and the optical properties of the films. This approach allows the preparation of nanocrystalline crack-free films and micro patterns. The amorphous thin films were prepared by a sol-gel method. The films were annealed by a CO₂ laser beam for various time intervals. The laser irradiation induced a crystallization process that resulted in the formation of Eu₂Ti₂O₇ nanocrystals. The nanocrystals regularly grew with increasing irradiation time reaching the size from 25?nm to 45?nm. A film of a thickness 480?nm exhibited an optical transmission of 91.9% that is close to the maximal theoretical limit. The film's refractive index at 632?nm was 2.26. A micrometric pattern was prepared by a direct laser writing followed by a wet chemical etching. Feasibility of the demonstrated approach, together with the high film's quality, and europium-titanate chemical resistivity open up many opportunities for advanced applications. The approach can be used for a preparation of protective coatings and integrated photonic devices such as planar optical waveguides and couplers.