微胶囊化红磷阻燃剂的制备及其在PA66中的应用

为克服红磷直接应用于PA66中的缺点，研究了用原位聚合法制备微胶囊红磷的工艺，测试了样品的吸湿性以及表面包覆性能，并研究了其用于PA66的阻燃性能和力学性能。结果表明，制得的微胶囊化红磷应用于PA66中，不仅具有优良的阻燃性能(FV-0级)，而且力学性能比单独应用红磷有所提高，加工工艺性能有较大幅度的提高。     

壳聚糖脱乙酰度对海藻酸钠/壳聚糖微胶囊的表面性质及蛋白吸附的影响

采用流动电势技术、 接触角技术及表面轮廓技术分别考察了由不同脱乙酰度壳聚糖制备的海藻酸钠/壳聚糖(ACA)膜的表面电荷分布、 表面亲疏水性、 表面粗糙度, 并以纤维蛋白原为模型, 采用静态吸附实验技术考察了表面性质对蛋白在ACA微胶囊表面的吸附量及吸附构象的影响。结果表明, ACA微胶囊表面净电荷为负, 表面正电荷随脱乙酰度的降低而减少。由脱乙酰度60%~90%壳聚糖制备的ACA膜的表面接触角均为70°左右, 且无显著性差异。ACA微胶囊表面呈颗粒状结构, 表面粗糙度随壳聚糖脱乙酰度的降低而减小。蛋白吸附分析表明, "棒状"的纤维蛋白原分子以"侧向"和"直立" 2种形式吸附于ACA微胶囊表面。当壳聚糖脱乙酰度较低时, 蛋白吸附量较小, 且此时蛋白多以"直立"形式吸附。以上结果表明, 由壳聚糖脱乙酰度带来的ACA微胶囊表面性质差异不仅影响了蛋白吸附量, 而且影响了蛋白吸附方式。      

微胶囊APP的制备及其在PP阻燃中的应用

通过原位聚合的方法制备了2种新型微胶囊聚磷酸铵(APP)MAPP-1和MAPP-2,并通过与聚丙烯(PP)共混制备了PP/APP、PP/MAPP-1及PP/MAPP-2复合材料。利用傅里叶红外光谱仪、微量燃烧仪、接触角仪、扫描电子显微镜及电子拉力机等对MAPP-1和MAPP-2的结构和复合材料的性能进行了表征,研究了微胶囊化前、后的APP对PP阻燃性能、力学性能和耐水性能的影响。结果表明:微胶囊化后的APP表面成功地包裹了一层聚脲材料,与PP/APP相比,复合材料PP/MAPP-1和PP/MAPP-2的阻燃性能更好,而且耐水性能和机械性能也较好。     

纳米TiO2修饰壳聚糖/石蜡相变微胶囊的制备与性能研究

以36℃相变石蜡为芯材，天然高分子壳聚糖为壁材，纳米二氧化钛(TiO₂)修饰壳体，利用乳化交联法制备了具有抗紫外功能性的相变微胶囊。探讨了不同因素对微胶囊性能的影响，经实验优化，当乳化剂用量为10%,油水相比例为3∶1,纳米TiO₂添加量为0.12g时，制得的相变微胶囊包覆率可达81.61%。通过扫描电镜、差示扫描量热仪、热重分析仪和紫外-可见分光光度计等分析，结果表明相变微胶囊表面光滑、形态规整，相变潜热为118.90J/g,具有良好的热循环和热稳定性，以及紫外屏蔽功能性。     

脲醛树脂包覆聚硫密封剂微胶囊的制备和性能EI北大核心CSCD

以脲醛树脂为壁材、聚硫密封剂为芯材,采用原位聚合制备出聚硫密封剂微胶囊,并使用红外光谱、扫描电镜等手段表征了微胶囊的结构和形貌。为了研究微胶囊化过程对密封剂固化胶膜力学性能的影响,将聚硫密封剂微胶囊与一定比例的硫化剂均匀混合分别制备成标准螺母试件或胶膜试片,依据相关标准系统考察了聚硫密封剂包覆前后破坏力矩、拆卸力矩和拉伸性能以及硬度的变化。结果表明,基于脲醛原位聚合可制备出形貌规则、粒径均一、表面相对粗糙、包覆膜致密的聚硫密封剂微胶囊,与未包覆密封剂相比包覆后聚硫密封剂胶膜的力学性能大幅度提高。     

微胶囊在聚合物材料中的应用研究进展

以微胶囊为媒介可以实现聚合材料的性能多元化。本文阐释了功能化微胶囊在聚合材料中的作用机理,简述了近年来它们在自润滑、自修复、阻燃领域的具体应用和现状,分析了功能化微胶囊的加入在实现了聚合材料的减摩抗磨、自我修复、阻燃等性能的同时对材料力学性能产生的影响。最后对微胶囊的未来研究方向进行展望。     

微胶囊技术在印刷油墨中的应用

在概述微胶囊技术的基础上,从特点、组成和制备实例等角度,重点介绍微胶囊型技术在油墨颜料粒子表面改性、功能性油墨和数字印刷油墨开发中的应用,以期为今后印刷油墨的研究和开发提供一些启示.     

TP/PA复合微胶囊对美国红鱼鱼片的保鲜性能研究

目的为了获得具有高效缓释和协同增效性能的水产品保鲜剂。方法采用喷雾干燥法分别制备茶多酚(TP)微胶囊、植酸(PA)微胶囊和TP/PA复合微胶囊,以美国红鱼为保鲜对象,测定其在温度4℃条件下的保鲜性能。结果保鲜剂处理可有效抑制鱼片中菌落总数(TVC)的生长,延缓pH值、硫代巴比妥酸(TBA)含量、挥发性盐基氮含量(TVB-N)的升高,有效地抑制鱼体感官评分和其硬度、弹性、咀嚼度、回复性等质构指标的下降,延长产品货架期。与未包埋保鲜剂处理的鱼片相比,在贮藏后期,经含有保鲜剂的微胶囊处理后,美国红鱼鱼片的保鲜效果更优,延长货架期3 d以上,即微胶囊中的保鲜剂在贮藏过程中缓慢释放,并作用于美国红鱼鱼片表面。TP/PA复合保鲜剂和复合微胶囊的保鲜性能均优于单一保鲜剂,说明复合保鲜剂具有协同增效作用。结论具有协同增效和缓释性能的TP/PA复合微胶囊能够显著延长美国红鱼鱼片的货架期3 d以上,可为微胶囊保鲜技术的深入研究和应用推广提供技术支持。     

防穴蚀微胶囊/环氧树脂涂料的制备及涂层结构

以甲基丙烯酸甲酯(BMA)、甲基丙烯酸丁酯(MMA)的共聚物为壁材、聚丙烯酰胺(PAM)水溶液为芯材,采用原位聚合法合成防穴蚀微胶囊,并将其加入环氧树脂中制成防穴蚀涂料.探究了硬度、附着力、抗冲击性、拉伸强度、最大吸水率等涂层力学性能的影响因素;采用磁致伸缩振动实验研究了涂料防穴蚀性能.结果表明,随着微胶囊用量及涂层厚度的增加,涂层防穴蚀性能提升但力学性能呈下降趋势.在此基础上,设计了一种新型结构涂层,即从涂层内部到表面,微胶囊含量由0％递增至5％,对比微胶囊均匀分布的涂层结构,新型涂层结构在力学性能和防穴蚀效果上均有显著提升.     

聚多巴胺修饰聚对苯撑苯并双噁唑纤维增强其抗老化性与功能性

高性能纤维聚对苯撑苯并双噁唑(PBO)容易受紫外光照射而导致其性能显著下降。为了提高PBO材料的抗老化性能,文中通过简易方法在纤维表面直接修饰富含酚羟基的纳米厚度的聚多巴胺薄层,并比较研究了初始纤维与多巴胺修饰纤维在紫外光照射前后的力学性能、热稳定性能、结晶取向等性能的变化。结果表明,未经修饰的PBO纤维的力学等性能在紫外光照射后显著下降,如拉伸强度下降了67%;而表面经过修饰的PBO纤维在经过紫外光照射后,其性能变化显著减小,如拉伸强度仅下降了33%。并且,聚多巴胺修饰的PBO纤维对污染物罗丹明B染料等具有一定的吸附性能,吸附24 h的吸附容量达0.25 mg/g。因此,在材料表面修饰聚多巴胺层可有效改善PBO纤维的抗紫外光老化性能,提高了材料的功能性。     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

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.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

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.     

Friction Stir Processing Strategies for Uniform Distribution of Reinforcement in a Surface Composite

Friction stir processing (FSP) is an important technique for preparing surface composites. Fabricating defect-free surface composites with uniform particle distribution by FSP is a challenging task. In this study, silicon carbide particles reinforced AA5083 alloy surface composites was fabricated using different FSP strategies including variation in process parameters, dual-tool processing and tool offset overlapping. Material flow of the processed material with reinforcement particles demonstrated that the distribution of particles was influenced by the stirring action of the probe as well as the extrusion of the plasticized material due to the movement of the tool. Process parameters, particularly rotational speed, showed a dominant influence on the distribution of silicon carbide particles.     

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.