种子乳液聚合法改性纳米TiO2及其表征

采用种子乳液聚合法对纳米TiO2进行表面改性，将甲基丙烯酸甲酯包覆在纳米TiO2表面，形成TiO2／PMMA复合粒子。采用FT-IR、XRD、XPS、TEM和激光粒度等分析手段对所得产物的形貌、尺寸、所携带官能团及表面元素变化情况进行了表征。结果表明复合粒子呈现核壳结构，粒子的粒径分布、团聚现象和分散性都得到改善。     

双亲性纳米TiO2复合粒子的制备与研究

采用疏水型硅烷偶联剂KH570表面接枝改性纳米TiO2,引入化学键结合的不饱和双键,再通过无皂乳液聚合法合成双亲性聚丙烯酸(PAA)-g-硅烷偶联剂KH570-g-纳米TiO2复合粒子.研究了偶联剂用量对纳米TiO2粒子分散性以及聚合条件对聚合物接枝率变化和微观形态的影响.红外光谱和热重测试分析结果表明,纳米TiO2表面偶联剂接枝率为7.62％,聚合物接枝率达61.3％;透射电镜观察表明,偶联剂处理使纳米TiO2的亲油性和分散性均提高,聚合物接枝后的复合粒子能够在有机溶剂中分散均匀且粒径增加至30nm左右.     

纳米TiO2改性及其掺杂聚苯乙烯性能的研究

为了增强无机化合物纳米TiO2的亲油性能,采用钛酸酯偶联剂LICA38对纳米TiO2表面进行预处理,并采用原位聚合工艺制备掺杂纳米Ti02的聚苯乙烯（PS）。采用DCA（dynamic contact angle）、XRD、FTIR、XPS、TEM等现代分析手段,对纳米TiO2预处理效果和掺杂材料的性能进行分析。结果表明,钛酸酯偶联剂在纳米TiO2的表面发生化学吸附,粒子的分散性提高,一定含量纳米TiO2的掺杂有助于提高PS的抗拉强度。     

纳米TiO2粒子的改性及其在有机硅自洁涂料中的应用

利用硅烷偶联剂KH-570对纳米TiO2粒子进行表面改性,并将改性后的纳米TiO2粒子应用于有机硅自洁涂料的制备。结果显示,纳米TiO2粒子表面改性成功,且在有机硅自洁涂料中呈现出良好的分散性。实验进一步考察了纳米TiO2粒子的添加量对有机硅自洁涂层的影响。结果显示,随着纳米TiO2粒子用量的增加,涂层的接触角先增大后...     

TiO2／PS复合粒子制备技术研究

本文首先通过优选表面活性剂和处理方式,实现了纳米TiO2粒子表面疏水处理,然后利用超声波的分散、粉碎、活化、引发等多重作用,在实现纳米TiO2粒子在反应介质中均匀分散的同时,引发苯乙烯（St）单体在纳米TiO2粒子表面进行分散聚合反应,最终制备出了TiO2／聚苯乙烯（TiO2／PS）复合粒子,并对其结构进行了表征。     

乳液聚合法制备TiO2/PS复合粒子及其性能研究

采用乳液聚合法制备了以纳米二氧化钛(TiO2)为核,聚苯乙烯(PS)为壳的复合粒子.利用正交实验研究了引发剂用量、单体用量、表面活性剂浓度对复合粒子包覆效率的影响;通过透光率和亲水亲油实验,检验复合粒子的分散性,并采用透射电镜(TEM),红外光谱(FTIR)表征了复合粒子的形貌和结构.     

纳米TiO_2粒子的改性及其在有机硅自洁涂料中的应用

利用硅烷偶联剂KH-570对纳米TiO2粒子进行表面改性,并将改性后的纳米TiO2粒子应用于有机硅自洁涂料的制备。结果显示,纳米TiO2粒子表面改性成功,且在有机硅自洁涂料中呈现出良好的分散性。实验进一步考察了纳米TiO2粒子的添加量对有机硅自洁涂层的影响。结果显示,随着纳米TiO2粒子用量的增加,涂层的接触角先增大后减小,当纳米TiO2粒子的用量为0.25%时,涂层接触角最大,达到129°。最后对涂膜的耐污、耐候性能进行了测试,发现涂膜具有良好的防水耐污性及耐老化性。     

氢等离子体电弧法Mg／TiO2复合纳米粒子的制备与表征

采用氢等离子体电弧法,在H2＋Ar气氛下制备出Mg／TiO2复合纳米粒子．通过X射线衍射仪（XRD）、红外分析（FT—IR）、高分辨透射电镜（HRTEM）对纳米粒子的化学成分、晶体结构和表面形貌进行了分析,发现具有六方形晶体惯态的镁粒子通过表面包覆一层TiO2后形成了球形粒子;分析了其形成过程．热重分析（TGA—SDTA）结果表明,Mg／TiO2复合纳米粒子比纯Mg纳米粒子抗氧化温度提高30～40℃．     

纳米CaCO3/TiO2复合粒子制备超疏水膜

采用溶胶-凝胶法,用γ-(2,3-环氧丙氧基)丙基三甲基氧硅烷和油酸修饰纳米CaCO3/TiO2复合粒子,制备具有类似荷叶表面形貌的超疏水涂层。结合扫描电镜、红外光谱、热重和示差扫描量热仪对复合粒子进行表征。结果表明,纳米TiO2粒子物理复合在纳米CaCO3表面,复合粒子经修饰后引入了疏水性的甲基,形成纳米复合双重粗糙结构,使所制备的涂层表现出优良的超疏水性能,其中接触角为162.1°,滚动角7°。     

纳米TiO_2/SiO_2的制备与表征及其光催化活性的研究

针对二氧化钛(TiO2)纳米颗粒极易团聚、分散性差的问题,以提高TiO2分散稳定性与光催化活性为目的,采用并流中和法,以锐钛矿型纳米TiO2粉体为载体,硅酸钠(Na2SiO3)为包覆剂,使用硫酸(H2SO4)调节pH值,在纳米TiO2表面包覆致密的氧化硅(SiO2)膜。借助Fourier变换红外光谱(FTIR),X射线能量散射谱(EDS)和场发射扫描电子显微镜(FESEM)表征样品的键合情况、表面化学成分、分散性,同时借助紫外-可见分光光度计(UV-Vis Spectrophotometer)以亚甲基蓝的光催化降解反应对其光催化活性进行评价。FTIR和EDS结果表明:采用该包覆法后,SiO2以化学键合的方式沉积在纳米TiO2表面,在包覆层和纳米TiO2颗粒之间的界面上形成了Ti—O—Si键。SEM结果表明:TiO2/SiO2纳米复合粒子分散均匀,无严重团聚和大块堆积现象。光催化实验结果表明:以SiO2表面包覆后的TiO2颗粒光催化活性明显高于纯TiO2。     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

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.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

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.……     

Deposition and Coating Properties on CVD Tungsten

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.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

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.     

Low-Temperature Properties of Silver

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.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

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.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

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.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

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.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

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.     

Evaluation of fatigue life of steel using steel grain size

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.