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1.
多孔TiO2光催化纳米薄膜的制备和微观结构研究   总被引:14,自引:0,他引:14  
锐钛矿型多孔TiO纳米薄膜可以从含聚乙二醇(PEG)的钛酸盐溶胶前驱体中通过溶胶-凝胶法制备.涂层的形貌,如孔的大小和孔的分布可以通过聚乙二醇的加入量和分子量来控制.当聚乙二醇的加入量和分子量越大,聚乙二醇热分解后在薄膜中产生的气孔就越多和孔径越大.随着TiO薄膜中气孔孔径和数量的增加,光的散射增强,薄膜的透光率减小.通过扫描电镜(SEM)和重量法测定了薄膜的厚度,每镀一次薄膜的厚度增加约为0.08μm.通过X射线光电子能谱(XPS)和红外光谱(IR)确定了多孔TiO纳米薄膜中元素的化学组成和表面羟基含量.实验结果表明:薄膜中除含有Ti、O元素外,还有一定量来自有机前驱物中未完全燃烧的碳和少量从玻璃表面扩散到薄膜中的Na和Ca元素;同时发现薄膜表面的羟基含量随聚乙二醇的加入量的增加而增加  相似文献   

2.
Al2O3—SiO2—TiO2复合陶瓷薄膜的制备与结构   总被引:1,自引:0,他引:1  
曾智强  萧小月 《功能材料》1997,28(6):599-603
本文利用Sol-Gel法制备了Al2O-SiO2-TiO2复合陶瓷薄膜,讨论了主要内容是体系成分(Al:Si:Ti摩尔比)对落膜制备过程及结构的影响。通过分步水解法可以得到稳定的Al2O3-SiO2-TiO2复合溶胶,进而制备复合陶瓷薄膜。组分间的静电作用是溶胶凝结的原因。三组分中,Si/Ti摩尔比是决定溶胶稳定性的主要因素。通过XRD对薄膜的相组成进行了分析,表明复合薄膜由Al4Ti2SiO12  相似文献   

3.
TiO2光催化薄膜的XPS研究   总被引:15,自引:0,他引:15  
利用TiO2溶胶通过浸涂技术在钠钙玻璃表面制备了TiO2光催化薄膜,根据X射线光电子能谱(XPS)对薄膜进行了表征。结果表明,薄膜中除含有+4价Ti的氧化物外,还有一定量的+3和+2价Ti的氧化物。结合有机基团燃烧的还原作用、玻璃中钠与钙离子的扩散和Ar离子刻蚀,对这种现象作了讨论。Ols的高分辨谱比文献报道的更复杂。元素在薄膜内层的分布更均匀,从表面到内层,O和Ti元素的含量明显增加,而C、Na  相似文献   

4.
纳米微孔SiO2薄膜的Sol—Gel制备及气孔率控制   总被引:7,自引:1,他引:6  
方国家  姚凯伦 《功能材料》1999,30(2):190-192
本文报道了纳米微孔SiO2薄膜的溶胶-凝胶(sol-gel)制备工艺,利用椭圆偏振光测试仪(Ellipsometer)直接测量了薄膜的厚度、折射率、从而得到了SiO2薄膜的气孔率及气孔大小分布。研究了合成工艺条件及浓H2SO4表面修饰对SiO2薄膜气孔率及稳定性的影响。  相似文献   

5.
医用NiTi合金表面溶胶-凝胶法制备TiO2-SiO2薄膜   总被引:4,自引:0,他引:4  
采用溶胶-凝胶法在NiTi形状记忆合金表面制备了TiO-SiO复合薄膜,在提高医用NiTi合金的抗腐蚀性方面,收到了显著的效果.运用电化学方法对不同组成的TiO-SiO薄膜在模拟体液中的腐蚀行为进行了研究,结果表明,随薄膜中 Ti/Si比的增加,TiO-SiO薄膜的抗腐蚀性增强.划痕试验表明 TiO-SiO(Ti/Si=4:1)膜与NiTi合金基体具有较高的界面结合强度.用原子力显微镜(AFM)对TiO-SiO薄膜的表面形貌及表面粗糙度进行观察和分析,解释并讨论了TiO-SiO薄膜的配方组成与其抗腐蚀性的关系,SiO含量较少时,薄膜结构致密,膜层均匀平滑,且膜基结合力好,作为医用NiTi合金的表面保护层,可以使其耐腐蚀性有显著提高.  相似文献   

6.
流态化CVD制备TiO2—Al2O3复合粒子   总被引:6,自引:0,他引:6  
本文探讨了流态化CVD反应器中Ti(OC4H9)4水解制备TiO2-Al2O3复合粒子新工艺,借助于SEM、TEM、BET、XRF和EPMA等现代测试手段研究了复合粒子结构和包覆过程特征。结果表明,在流态化CVD反应器中Al2O3超细颗粒以团聚体形式存在,TiO2包覆量随Ti(OC4H9)4进料浓度升高而增加,但反应温度影响不大;在包覆过程中,同时存在成核和成膜,成核包覆使复合粒子比表面积增加,成  相似文献   

7.
本文探讨了流态化CVD反应器中Ti(OC4H9)4水解制备TiO2-Al2O3复合粒子新工艺,借助于SEM、TEM、BET、XRF和EPMA等现代测试手段研究了复合粒子结构和包覆过程特征.结果表明,在流态化CVD反应器中Al2O3超细颗粒以团聚体形式存在,TiO2包覆量随Ti(OC4H9)4进料浓度升高而增加,但反应温度影响不大;在包覆过程中,同时存在成核和成膜,成核包覆使复合粒子比表面积增加,成膜包覆使复合粒子比表面积减小.  相似文献   

8.
离子束辅助沉积制备TiO_2-Nb_2O_5氧敏薄膜   总被引:1,自引:0,他引:1  
采用离子束辅助沉积方法在Al2O3陶瓷衬底上制备了TiO2Nb2O5氧敏薄膜。考察了薄膜组分比及退火温度对薄膜氧敏特性和结构的影响。电阻氧分压特性测试结果表明,纯Nb2O5薄膜的氧敏特性优于纯TiO2薄膜;掺入少量的Ti可使Nb2O5薄膜的氧敏特性提高,以5mol%TiO2掺杂的Nb2O5薄膜最佳;过量掺杂则使Nb2O5薄膜的氧敏特性明显变差。在5mol%TiO2Nb2O5薄膜中再掺入少量的Pt(03%05%)可使其氧敏特性更好,而且其响应时间大大缩短。X射线衍射谱(XRD)和X射线光电子谱(XPS)分析表明,在退火后的TiO2Nb2O5薄膜中Nb2O5为单斜(Mform)结晶相,而掺杂的Ti以非晶的TiO2形式存在,即使在高达34mol%TiO2Nb2O5薄膜中也不例外。纯TiO2膜为金红石结构。不同退火温度(90011000C)对薄膜的氧敏特性和结构无明显影响。  相似文献   

9.
用溶胶-凝胶法在Pt/Ti/SiO2/Si(100)基底上制备Pb1-xLaxTiO3(PLT,x〈0.2)薄膜,研究薄膜的结构及其介电、铁电性能。在600℃下退火1小时的PLT薄膜表现出单一的钙钛矿结构,(100)择优取向明显,在室温下PLT薄膜有典型的电滞回线。在x〈0.2(摩尔比)的范围内,PLT薄膜相对介电常数则随着La的增加而增加。  相似文献   

10.
通过 sol-gel工艺在普通钠钙玻璃表面制备了均匀透明的 TiO2/SiO2复合薄膜.实验结果表明:在 TiO2薄膜中添加 SiO2,可以抑制薄膜中 TiO2晶粒的长大,同时薄膜表面的羟基含量增加,水在复合薄膜表面的润湿角下降,亲水能力增强.当 SiO2含量为 10~20 mol%时获得了润湿角为0°的超亲水性薄膜.  相似文献   

11.
A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.  相似文献   

12.
The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……  相似文献   

13.
Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.  相似文献   

14.
We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.  相似文献   

15.
Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.  相似文献   

16.
ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.  相似文献   

17.
As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.  相似文献   

18.
Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.  相似文献   

19.
TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.  相似文献   

20.
The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.  相似文献   

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