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1.
利用电导率(K)-增溶水量(ml)关系曲线研究了CTAB/正丁醇/环己烷/水四组分微乳体系在不同增溶水量时的3种结构,即油包水(W/O)、油水双连续(BC)、水包油(O/W)。讨论了表面活性剂CTAB与助表面活性剂正丁醇不同浓度时对微乳液稳定性的影响,得出了微乳液稳定时CTAB和正丁醇的合适配比。  相似文献   

2.
包覆表面活性剂的TiO2电流变液   总被引:8,自引:0,他引:8  
利用W/O微乳液法,分别由水/SPan80或DBS/正戊醇/环己烷形成W/O微乳液,将钛醇盐在微乳中以水核为中心水解,制得包覆表面活性剂的TiO2粒子,包覆表面活性剂可显著提高TiO2的电流变活性,且非离子型表面活性剂的效果远好于离子型表面活性剂,一种典型的颗粒/硅油体积比为31%的电流变液在3kV/mm直流电场下的剪切 应力为1.4KPa,约为纯TiO2的3倍,漏电流密度小于25uA./cm2,当Span80与TiO2的质量比为7-13%,时有最佳电流变效应,包覆适量的非郭子表面活性剂明显优化电流变液的温度效应,改善颗粒的悬浮稳定性。  相似文献   

3.
研究了NH3·H2 O皂化二 - (2 -乙基己基 )磷酸微乳液体系增溶水过程微观结构的转变 ,测定了增溶水过程电导率和粘度的变化 ,以及在一定溶水量时电导率和温度的关系 ,求得了微乳液颗粒的活化能  相似文献   

4.
《膜科学与技术》2001,21(4):25-28
研究了NH3*H2O皂化二-(2-乙基己基)磷酸微乳液体系增溶水过程微观结构的转变,测定了增溶水过程电导率和粘度的变化,以及在一定溶水量时电导率和温度的关系,求得了微乳液颗粒的活化能.  相似文献   

5.
为了研究双微乳液法在制备纳米级光催化剂的应用,以TiCl4和NH3.H2O为原料,采用十六烷基三甲基溴化铵-正丁醇-环己烷-水微乳体系制备Fe3+掺杂纳米TiO2,对粉末的晶体结构进行X射线衍射表征,并以其对p-甲酚的降解考察其光催化活性。结果表明,在较小的掺杂量时,Fe3+掺杂量的提高可以提高TiO2的光催化活性,进一步提高掺杂量将引起光催化活性的降低;掺杂Fe3+可导致纳米TiO2的粒径减小;Fe3+的半径较小以及Fe2O3的熔点较低均有利于TiO2从锐钛矿向金红石的相变;当Fe3+掺杂摩尔分数为0.06%,煅烧温度为550℃时,纳米TiO2的光催化活性最高,此时形成TiO2的锐钛矿和金红石相的混晶;乳液中含水量也会影响晶相的组成和粒径大小,随着含水量增加产物中出现了一定比例的金红石相。  相似文献   

6.
微乳体系相行为研究及铂纳米微粒的制备   总被引:3,自引:0,他引:3  
对十六烷基三甲基溴化铵 (CTAB) -正辛醇 -环己烷 -H2 O微乳体系相行为进行了研究。采用分光光度计测量了表观稳定的微乳体系的吸光度的变化 ;然后采用 3种CTAB与正辛醇配比的微乳体系在 30℃下制备出了Pt纳米微粒 ,还原剂为水合肼。经透射电镜分析得出 :溶水量较大的微乳体系可以制备出粒径较小 (d =3nm)且分布极为均匀的铂纳米微粒  相似文献   

7.
采用W/O型微乳液法制备出了CNTs/PbO和CNTs/CuO,利用电导率仪测量体系的溶水量,通过绘制三元相图研究了微乳液组成的表面活性剂和助表面活性剂的配比、温度以及盐的浓度等因素对W/O型微乳液相区的影响。分析得出最佳微乳液体系环己烷和活性剂的比为4 6,表面活性剂和助表面活性剂的比为2 3,反应温度为25℃。根据推进剂的成分,将一定量的燃烧催化剂和黑索今混合,通过热分析表征CNTs/PbO、CNTs/CuO对黑索今的催化热分解。结果表明,新的催化剂明显加快黑索今的热分解,分解峰位降低16.07℃。  相似文献   

8.
应用电导率法研究了TritonX-100/正戊醇/环己烷体系中各组分及条件对微乳液最大增溶水量的影响。结果表明:当表面活性剂TritonX-100用量为3ml,助表面活性剂选正戊醇用量为1ml,环己烷为油相,温度为48℃,Ca(NO3)2溶液与(NH4)2HPO4溶液分别为0.24和0.14mol/L时,体系增溶水量最大,可得到较高产率的纳米羟基磷灰石。并且用XRD和TEM手段对产物进行了表征。  相似文献   

9.
制备纳米颗粒主要采用w/o型微乳液、可分为单微乳液法和双微乳液法.本文对微乳液法制备纳米粉体粒度的主要影响因素如水核半径、反应物浓度、微乳液界面膜强度等进行讨论的基础上.对微乳液法制备纳米TiO2光催化剂常见微乳液体系进行了介绍.并讨论了制备过程中的一些影响因素,并提出了进一步的研究方向.  相似文献   

10.
利用电导率(K)-增溶水量(ml)关系曲线研究了CTAB/正丁醇/环己烷/水四组分微乳体系在不同增溶水量时的3种结构,即油包水(W/O)、油水双连续(B.C.)、水包油(O/W).讨论了表面活性剂CTAB与助表面活性剂正丁醇不同浓度时对微乳液稳定性的影响,得出了微乳液稳定时CTAB和正丁醇的合适配比.  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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