热处理对溶胶-凝胶TiO2薄膜的晶相转变和性能影响

以钛酸丁酯（TPOT）为有机醇盐前驱体，采用溶胶－凝胶技术制备了TiO2溶胶。为测量方便起见，分别制备了凝胶粉体和薄膜，并对样品进行了不同温度的热处理。X射线衍射（XRD）、椭偏仪和紫外－可见光谱（UV－vis)的测量表明：随热处理温度的升高，TiO2的结构由非晶到锐钛矿再到金红石相转变，400℃为锐钛矿相，600℃开始出现金红石相，800℃完全转变为金红石相；晶粒尺寸随热处理温度的升高而逐渐增大，锐钛矿结构的晶粒尺寸范围是2.5-5.5nm，金红石结构的晶粒尺寸范围是5.9-6.8nm；TiO2薄膜的折射率随热处理温度的升高而增大，同时薄膜厚度降低；禁带宽度随热处理温度的升高而增大，同时薄膜厚度降低；禁带宽度随热处理温度升高而变窄，锐钛矿结构的禁带宽度为3.45eV，而金红石结构的禁带宽度为3.30eV。     

退火温度对TiO2薄膜结构和表面形貌的影响

研究了退火温度对中频交流反应磁控溅射技术制备的TiO2 薄膜结构和表面形貌的影响。利用X射线衍射仪和原子力显微镜 ,检测了TiO2 薄膜的晶体结构和表面形貌。实验结果显示 :沉积态TiO2 薄膜为非晶态 ;低温 (70 0℃以下 )退火后 ,TiO2 薄膜出现锐钛矿相 ,晶粒长大不明显 ;高温退火 (90 0℃以上 )后 ,薄膜转变为金红石相 ,晶粒由柱状转变为棱状 ,并迅速长大至微米量级     

退火温度对TiO2薄膜结构和表面形貌的影响

研究了退火温度对中频交流反应磁控溅射技术制备的TiO2薄膜结构和表面形貌的影响。利用X射线衍射 仪和原子力显微镜，检测了TiO2薄膜的晶体结构和表面形貌。实验结果显示：沉积态TiO2薄膜为非晶态；低温（700℃以下）退火后，TiO2薄膜出现锐钛矿相，晶粒长大不明显；高温退火（900℃以上）后，薄膜转变为金红石相，晶粒由柱状转变为棱状，并迅速长大至微米量级。     

退火温度对TiO2薄膜结构与光学性能的影响

研究退火温度对薄膜相结构、表面化学组成、形貌及光学性能的影响.采用射频磁控溅射法在单晶硅片和石英玻璃片上负载TiO2薄膜,通过X射线衍射(XRD)、原子力显微镜(AFM)、X光电子能谱(XPS)和紫外可见光谱(UV-vis)对其进行表征.结果表明,常温制备400℃以下退火的TiO2薄膜为无定形结构,400℃以上退火的TiO2薄膜出现锐钛矿相,600℃以上退火的TiO2薄膜开始出现金红石相,退火温度在1000℃以上时样品已经完全转变为金红石相;高温退火薄膜的组成为TiOx;随着退火温度的升高,薄膜透射率下降,折射率和消光系数有所增加.     

TiO2纳米薄膜的制备及其紫外-可见光谱研究

用磁控溅射技术在普通载玻片上制备了不同厚度透明的锐钛矿相二氧化钛(TiO2)纳米薄膜,利用X射线衍射仪(XRD)、场发射扫描电子显微镜(FE-SEM)等分析方法对试样进行表征,并测试了其紫外-可见透射光谱,计算了此薄膜的禁带宽度,其值接近TiO2禁带宽度的理论值3.2eV.     

纳米TiO2薄膜的制备与表面形貌研究

研究退火温度对薄膜相结构、表面化学组成及形貌的影响。采用射频磁控溅射法在单晶硅片上淀积TiO2薄膜,通过X射线衍射（XRD）、原子力显微镜（AFM）和X光电子能谱（XPS）对其进行表征。结果表明,室温制备400℃以下退火的TiO2薄膜为无定形结构,400℃以上退火的TiO2薄膜出现锐钛矿相,600℃以上退火的TiO2薄膜开始出现金红石相,退火温度在1000℃以上时样品已经完全转变为金红石相;随着退火温度的升高,晶粒尺寸和表面粗糙度逐渐增大,但是当退火温度为1000℃时反而有所减小,晶粒尺寸和表面粗糙度在退火温度为1000℃时发生的这一突变现象,是由该退火温度下的相变导致。     

基底温度对直流溅射Nb掺杂TiO2薄膜性能的影响

采用陶瓷靶直流磁控溅射,以玻璃为基底制备2.5wt%Nb掺杂TiO2薄膜,控制薄膜厚度在300~350 nm,研究了不同基底温度下所制得薄膜的结构、形貌和光学特性.XRD分析表明,基底温度为150℃、250℃和350℃时,薄膜分别为非晶态、锐钛矿(101)和金红石相(110)结构.基底温度250℃时,锐钛矿相薄膜的晶粒尺寸最大,约为32 nm.薄膜表面形貌的SEM分析显示,薄膜粗糙度和致密度随基底温度升高得到改善.薄膜的平均可见光透过率在基底温度为250℃以内约为70%,随基底温度升高至350℃,平均透过率下降为59%,金红石相的存在不利于可见光透过.Nb掺杂TiO2薄膜的光学带宽在3.68~3.78 eV之间变化.基底温度为250℃时,锐钛矿相薄膜的禁带宽度最大,为3.78 eV.     

纳米TiO2薄膜的制备及其光催化性能研究

采用溶胶-凝胶(Sol-gel)法在玻璃衬底上制备了纳米TiO2薄膜.采用X射线衍射仪(XRD)、紫外可见一光谱(UV/vis)和原子力显微镜(AFM)对纳米TiO2进行表征.结果表明,经300～700℃退火得到的TiO2粉体呈锐钛矿相,经800℃退火得到了锐钛矿相与金红石相的混合晶相,经900℃退火完全转化为金红石相.薄膜表面粒子分布均匀,表面平均粗糙度为1.54nm,该薄膜具有较高的光催化活性,可直接用于光催化降解有机物等领域,具有广阔的应用前景.     

不同晶体结构氧化钛薄膜性能研究

用非平衡磁控溅射技术分别制备了锐钛矿、金红石、锐钛矿和金红石共存结构的氧化钛薄膜.用X射线衍射(XRD)分析薄膜的晶体结构,血小板粘附和凝血因子实验研究薄膜的血液相容性,分光光度计和接触角测量法测试薄膜表面物化性质.研究表明,氧化钛薄膜具有宽禁带的半导体特性,血液相容性优于热解碳.金红石结构氧化钛薄膜由于其与血浆白蛋白、血浆纤维蛋白原、血液及水之间有较小的界面张力,自身较低的表面能色散分量与极性分量的比值,加之其宽禁带宽度的n型半导体特性使其具有最优的血液相容性.     

Si掺杂锐钛矿相TiO2的电子能带结构

利用基于密度泛函理论的第一性原理方法对Si掺杂前、后锐钛矿相TiO2的电子能带结构、电子态密度以及吸收光谱进行计算。结果表明,Si掺杂导致锐钛矿相TiO2的禁带宽度略增大0.048 eV;掺杂前锐钛矿相TiO2的价带和导带主要由O的2p和Ti的3d轨道构成,Si掺杂后其价带和导带主要由Si的3p、Ti的4s和Ti的3d轨道构成;Si掺杂可导致锐钛矿相TiO2的吸收边蓝移。     

Sn2+掺杂硫化铜的制备及其性能

以硫脲(NH2CS)、氯化铜(CuCl2)、氯化亚锡(SnCl2)为原材料采用直接沉淀法制备掺杂Sn^2+的纳米CuS近红外光吸收材料,并对样品的光学性能和物相结构进行了表征,分析部分合成条件对其光吸收性能的影响。结果表明,所制备产物为纯相Sn^2+掺杂的CuS晶体,制备工艺条件将对产物的光吸收性能及光热转换性能产生直接影响,在反应体系铜与硫的物质量之比为1∶17,NaOH加入量0.008mol,Sn^2+掺杂量5%时,反应4h可得到光吸收性能较优的样品,样品光热转换效率为23.02%,与纯相未掺杂CuS样品相比,光热转换效率提高了80.97%。     

Effect of glass in aluminum matrix on workability and strain hardening behavior of powder metallurgy composite

A complete experimental investigation on workability behavior of the Al–Glass has been carried out during cold upsetting. The present study has been performed to evaluate the effect of different percentage of Glass addition in Powder metallurgy (P/M) preforms of Al–Glass composite on workability behavior. The material studied in this paper is aluminum with glass as reinforcement. Glass content has been varied from 0% to 8% with particle size of 60 μm. The experimental results were analyzed for workability under triaxial stress state condition as a function of the relative density. The formability stress index (β), stress ratio parameters (σ_θ/σ_eff) were obtained for each percentage addition of Glass. It is found that as percent content of Glass increases, the workability parameter also increases. The addition of glass in Aluminum matrix affects the strain hardening index (n) of the composite.     

Characterization of TiO(2)-chitosan/glass photocatalyst for the removal of a monoazo dye via photodegradation-adsorption process

In this paper, the newly explored TiO(2)-Chitosan/Glass was suggested as a promising alternative material to conventional means of wastewater treatment. Characterization of TiO(2)-Chitosan/Glass photocatalyst was studied with SEM-EDX, XRD, and Fourier transform infrared spectroscopy (FTIR) analysis. The combination effect of photodegradation-adsorption process for the removal of methyl orange (MO), an acid dye of the monoazo series occur promisingly when four layers of TiO(2)-Chitosan/Glass photocatalyst was used for MO removal. Approximately, 87.0% of total MO removal was achieved. The reactive -NH(2), -OH, and metal oxide contents in the prepared photocatalyst responsible for the photodegradation-adsorption effect were confirmed by FTIR study. Similarly, MO removal behavior was well supported by SEM-EDX and XRD analysis. Significant dependence of MO removal on the TiO(2)-Chitosan loading can be explained in terms of relationship between quantum yield of photocatalytic reactions and photocatalyst structure/activity. Hence, the research work done thus far suggests a new method, having both the advantages of photodegradation-adsorption process in the abatement of various wastewater pollutants.     

Moiré patterns between aperiodic layers: quantitative analysis and synthesis

Moiré effects that occur in the superposition of aperiodic layers such as random dot screens are known as Glass patterns. Unlike classical moiré effects between periodic layers, which are periodically repeated throughout the superposition, a Glass pattern is concentrated around a certain point in the superposition, and farther away from this point it fades out and disappears. I show that Glass patterns between aperiodic layers can be analyzed by using an extension of the Fourier-based theory that governs the classical moiré patterns between periodic layers. Surprisingly, even spectral-domain considerations can be extended in a natural way to aperiodic cases, with some straightforward adaptations. These new results allow us to predict quantitatively the intensity profile of Glass patterns; furthermore, they open the way to the synthesis of Glass patterns that have any desired shapes and intensity profiles.     

Effect of Polymer Form and its Consolidation on Mechanical Properties and Quality of Glass/PBT Composites

The aim of this study was to understand the role of the processing in determining the mechanical properties of glass fibre reinforced polybutylene terephthalate composites (Glass/PBT). Unidirectional (UD) composite laminates were manufactured by the vacuum consolidation technique using three different material systems included in this study; Glass/CBT (CBT160 powder based resin), Glass/PBT (prepreg tapes), and Glass/PBT (commingled yarns). The different types of thermoplastic polymer resin systems used for the manufacturing of the composite UD laminate dictate the differences in final mechanical properties which were evaluated by through compression, flexural and short beam transverse bending tests. Microscopy was used to evaluate the quality of the processed laminates, and fractography was used to characterize the observed failure modes. The study provides an improved understanding of the relationships between processing methods, resin characteristics, and mechanical performance of thermoplastic resin composite materials.     

Verres formes par les oxysulfures de terres rares Ln2O2S

Glass formation in the Ln₂O₂S-Ga₂S₃ systems (Ln = La to Nd). Preparations. Extent of the glassy regions as a fonction of the R.E. content and of the nature of the R.E. : Vitreous transition temperatures and crystallization temperatures. Microhardness. Optical properties.     

纳米Al2O3/玻璃纤维/聚对苯二甲酸丁二醇酯复合材料非等温结晶行为研究--(Ⅰ)结晶与熔融行为

通过熔融共混法制备了纳米A l2O3/玻璃纤维(GF)/聚对苯二甲酸丁二醇酯(PBT)复合材料,利用差示扫描量热仪(DSC)对其非等温结晶过程、熔融行为及结晶度进行了研究。结果发现,纳米A l2O3粒子的异相成核作用有利于复合材料结晶速率的增加,使得非等温结晶温度提高,双熔融峰现象中的低温熔融峰的熔融温度也有所提高。同时,在PBT基体中,纳米A l2O3粒子在一定程度上可以改变玻璃纤维对复合材料结晶行为的影响而使结晶度发生改变。     

Hybrid GEE 方法和 QIF 方法的比较

在纵向数据分析中,广义估计方程（GEE）方法被广泛应用．无论相关矩阵是否正确识别,通过 GEE 方法得到的参数估计都是相合的．但是,当选取的工作相关矩阵与真实相关阵相差较大时,所得参数估计的效可能会较低．为了降低工作相关矩阵的选取对于参数估计的效的影响,研究者提出了二次推断函数（QIF）方法和 Hybrid GEE 方法．本文通过数值模拟对 QIF 方法和 Hybrid GEE 方法进行分析比较．     

磷化液中NaNO2浓度的快速测定

提出一种快速测定磷化液中NaNO2浓度的新方法--注射器法,并成功地应用于实际样品中NaNO2的测定.该方法简单、快速,测定范围宽,相对偏差小于2%,适用于溶液中NO2-浓度的测定,特别适用于生产现场磷化液中NaNO2的监控.     

Glass formation in the ZrF4-PbF2-LaF3-NaF system

Glass formation in the ZrF₄-PbF₂-LaF₃-NaF system is studied by differential thermal analysis at ZrF₄ contents of 65 and 70 mol %. The glass-forming region is outlined, and the composition dependences of glass stability parameters are presented.