聚苯乙烯蓝色胶体晶体膜的制备工艺

本文以单分散的粒径为340±10nm的聚苯乙烯微球为原料,采用垂直自组装法制备了蓝色聚苯乙烯胶体晶体膜。研究了乳液浓度、干燥温度、组装容积等因素对聚苯乙烯胶体晶体膜的微观形貌和呈色性能的影响。结果表明:当乳液浓度较小时,微球呈现单层均匀分布,局部发生自组装,当乳液浓度达到0.1wt%时,微球呈现多层密排六方排列,宏观上呈现明亮的蓝色。当干燥温度为40℃时,该胶体晶体膜微观形貌为高质量的密排六方结构,呈现均匀明亮的蓝色。对比试验得出,在50mL的容器中,PS微球容易发生自组装且呈现明亮均匀的蓝色。同时发现,该胶体晶体膜在较低强度的光线下呈色比较微弱,蓝色饱和度较低,在强烈的光照下,呈现出绚丽的蓝色。     

用光刻、软刻和氧化硅球晶体模板制备表面微结构

表面微结构的制备对获得超疏水性表面和改善生物医学材料性能具有重要意义. 为了制备微米、亚微米和纳米级表面微结构, 本文采用光刻(photo-lithography)和软刻技术(soft lithography) 制备了微米尺寸长方体或圆柱体的阵列, 压印出变形长方体(塔状)或圆柱体(圆盘状)阵列的微结构表面; 采用单分散氧化硅球自集聚紧密堆积而成的胶体晶体为模板, 制备了亚微米/纳米 尺寸网状微结构的表面. 用光学和扫描电子显微镜表征了所获得的表面微结构.     

基于胶体微球自组装光子晶体的结构生色

综述了近年来基于胶体微球自组装光子晶体结构生色的研究进展。先简要介绍了光子晶体和结构生色理论,然后阐述了以胶体微球为基本结构基元构筑光子晶体的自组装方法,探讨了光子晶体的结构色效果的表征方式和稳固性增强方法,最后总结了用胶体微球自组装法制备光子晶体的困难并展望了发展方向。     

双基片垂直沉降法自组装二氧化硅胶体晶体

采用St(o)ber法制备了适于自组装的单分散性的SiO2球体颗粒,再采用双基片垂直沉积法在无水乙醇中制备出SiO2胶体晶体.通过X射线衍射仪和场发射扫描电子显微镜(SEM)对胶体晶体的晶型和显微形貌进行测试分析.结果表明:所得SiO2球体颗粒为无定形态,粒径为70～380nm,粒径随着氨水浓度的增大而增大;随着双基片间距增大,胶体晶体周期性排列越紧密有序,相同基片间距下,双尺寸胶体晶体更难以获得.     

单分散SiO_2胶体光子晶体的自组装制备与表征(英文)

使用Stber法化学合成了粒径在200-350nm之间的单分散SiO2,采用垂直沉积技术自组装制备了胶体晶体薄膜。通过扫描电镜与分光光度计对样品的微观结构与透过光谱进行了表征,结果表明,组成胶体晶体的SiO2微球呈面心立方结构,膜层的厚度可以通过胶体溶液的浓度加以控制,胶体膜层透射光谱中出现的峰值位置取决于SiO2微球的大小,并且与布拉格定律理论计算的结果相一致,透射光谱中光学阻带的深度可以通过改变胶体悬浮液中SiO2颗粒的体积分数来调控。     

SiO2胶体晶体的自组装结构及其带隙特征

光子晶体是一种具有光子带隙的新型功能材料.利用垂直沉积自组装法制成SiO2胶体晶体,并利用扫描电子显微镜和紫外分光度计对胶体晶体的显微形貌和光学特征进行了研究.结果表明,利用垂直沉积法自组装得到的SiO2胶体晶体具有面心立方结构;在可见光波段,胶体晶体在＜111＞面方向存在光子带隙.     

光子晶体用二氧化硅胶体球的改性制备及其自组装

采用一步法制备了表面接枝甲基丙烯酰氧基三甲氧基硅烷(MPS)的单分散SiO2胶体球,并通过垂直沉积法在40℃、60%相对湿度下组装出有序性较好的密排结构的SiO2光子晶体.傅立叶红外光谱(FT-IR)和X射线光电子能谱(XPS)结果证明SiO2胶体球表面接枝上了MPS;扫描电子显微镜(SEM)结果表明改性后SiO2胶体球平均粒径为284nm,单分散性较高,平均标准偏差＜5%;制备出的光子晶体是面心立方(fcc)紧密堆积结构;吸收光谱表明,所制备的光子晶体在(111)方向具有光子晶体的带隙特性,带隙中心波长为646nm.     

基于自组装行为的微球复合水凝胶制备及性能

以超支化的聚乙烯亚胺和烯丙基缩水甘油醚通过环氧开环反应制备了具有温敏性的聚合物,该温敏性聚合物在水溶液中表现出相转变行为,当达到临界温度时能够自组装形成微球.以该微球为交联剂、丙烯酰胺为单体原位在室温下制备出一种微球复合水凝胶(MC H).力学性能测试表明,制备的微球复合水凝胶具有优异的力学性能,断裂伸长率达到2800％.流变行为分析表明,该凝胶是一种黏弹性材料,其网络结构兼具物理和化学双重交联.此外,凝胶还表现出良好的形变能力,循环拉伸测试表明其结构中存在明显的能量耗散机制.     

漂浮法制备高质量胶体晶体

采用漂浮自组装法制备出三维胶体晶体,并通过扫描电子显微镜对胶体晶体进行表征,观察并分析胶体晶体的形貌和结构。实验分别考察了各种因素(粒子种类、颗粒粒径、温度及固含量)对胶体晶体的形貌和结构的影响。结果表明,用漂浮法制得的聚苯乙烯(PS)胶体晶体比相同条件下SiO2胶体晶体排列更加有序,该法的最佳适用粒径为150 nm～500 nm,在特定温度(60℃～90℃)和固含量范围内均能在气液界面处自组装出大面积的三维有序胶体晶体。     

SiO_2/魔芋葡甘聚糖微球制备纤维多层结构的结构色

为了研究出一种光学和力学性质良好的结构色纤维,文中将魔芋葡甘聚糖应用于结构色纤维的加工,利用表面涂覆技术制备结构色纤维。通过显微镜观察结构色纤维的反射光谱,结果表明,提拉速度与纤维表面的胶体晶体层数成负相关关系,胶体浓度以及纤维尺寸与纤维表面的胶体晶体层数成正相关关系,纤维颜色随微球尺寸增大而红移,随微球尺寸变小而发生蓝移,而且当纤维表面的胶体晶体层数达到10层时,结构色纤维的颜色是稳定的。     

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.