Facile synthesis and charaterization of silica nanoscale ionic materials

A series of silica nanoscale materials(NIMs) were prepared through a facile acid-base neutralization. These silica derivatives consist of a nanosilica core, a charged corana(sulfonic acid SIT) attatched to the core, and an oppositely charged canopy (PEG-substituted tertiary amines) to balance the corona. By selecting proper canopy such as surface-functionalized, silica can behave viscous liquid in the absence of any solvent at room temperature. DSC results indicated the melting temperature and glass transition of the derivatives were slightly lower than those of the neat polymer canopy, indicating strong interaction between the core and PEG-substituted tertiary amine.     

高能球磨在复合材料制备中的应用

机械合金化（MA）技术作为一种制备新材料的有效方法已获得广泛的应用，利用该方法以获得常规条件下很难合成的具体独特性能的新型复合材料，高能球磨是机械合金化技术研究中的最新进展，利用高能球磨可在球磨过程中诱发低温化学反应，可制备性能优异的金属或陶瓷材料，介绍了利用高能球磨进行机械合金化的介面反应机理，固溶分解机理，自蔓延反应机理，高能球磨强度对材料制备的影响,机械合金化在金属基陶瓷复合材料和陶瓷基金属复合材料制备中的应用与发展。     

复合材料在柔性电化学储能装置中的应用及研究进展

柔性电化学储能(EES)装置,如锂离子电池(LIBs)和超级电容器(SCs),可集成于柔性电子器件中,在连续的力学形变条件下可为便携式装置的运行提供稳定的电源。柔性EES装置应同时具备较高的柔韧性、能量密度和功率密度,因此适合的电极材料、电解质以及先进的电极结构设计十分重要。近年来,用于柔性EES装置的具有特定组分和独特结构的复合材料得到了广泛的研究,且采用复合材料的装置的弯曲、拉伸和压缩能力远优于单组分材料装置的性能,因此,我们概述了用于柔性LIBs和SCs的柔性电极复合材料以及复合电解质的最新进展,并特别关注复合材料在可穿戴电子器件中柔性EES装置的应用,此外,还简要介绍了实现整个装置柔性和可拉伸性的结构设计,重点介绍了其未来的发展前景和研究方向。     

多壁碳纳米管负载ZnO纳米复合材料的制备及其光催化性能研究

采用溶胶法,以醋酸锌和硝酸处理过的多壁碳纳米管（MWCNTs）为主要原料,制备了MWCNTs-ZnO光催化复合材料。通过X射线衍射（XRD）、透射电子显微镜（TEM）、扫描电子显微镜（SEM）等手段研究了制得样品的形态结构;通过紫外-可见分光光度计（UV-vis）,在紫外光照射下,分析比较了MWCNTs-ZnO复合材料、MWCNTs和ZnO的混合物以及纯ZnO对甲基橙光催化降解的性能。结果表明：在相同条件下MWCNTs-ZnO复合催化剂对甲基橙光降解有着最高的光催化活性。讨论了复合催化剂用量、重复使用等因素对甲基橙光催化降解效果的影响,并就复合催化剂的抗光腐蚀机制进行了初步的探讨。     

Polyaniline supported 12-tungstosilicic acid as the catalyst for acetals and ketals synthesis

A novel environmental friendly catalyst, H₄SiW₁₂O₄₀/PAn was prepared and identified by FT-IR, XRD and TG/DTA. The optimal synthetic protocol was a PAn to H₄SiW₁₂O₄₀ mass ratio of 1: 1, a 20 mL of methanol and a reaction time of 2 h at reflux. It was used in catalytic synthesis of ten important ketals and acetals with a high catalytic activity. With an aldehyde/ketone to glycol molar ratio of 1: 1.5 and a 1 wt% catalyst loading, the yields of ketals and acetals could reach 60.0%–93.8 % after 1 h. Funded by the Natural Science Foundation of Hubei Province (No. 2005ABA053), Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, and the National Natural Science Foundation of China (No. 20471044)     

高性能复合陶瓷刀具材料

高性能陶瓷刀具材料需具备高硬度、高耐磨性和耐热性、抗粘结性和化学稳定性等性能 .讨论了复合陶瓷刀具材料结构与性能之间的关系 .从材料设计的角度 ,提出复合陶瓷刀具材料的设计思路和高性能陶瓷刀具的设计原则 ,详细讨论了设计原则中几个重要的性能指标和性能复合原则 .随着相关学科在理论和方法上的进展、交叉和测试手段的进步 ,高性能陶瓷刀具材料的设计会从定性分析逐渐步入定量描述的阶段 .     

New composite grouting materials:Modified urea-formaldehyde resin with cement

A new composite two component grout comprised of modified urea-formaldehyde resin and cement was formulated to take account of the advantages and disadvantages of both the cement grout and the chemical...     

一种合成片状结构聚苯胺的新方法

利用无模板法成功合成了片状结构的聚苯胺.用扫描电镜,红外和X射线衍射对产物进行了表征.通过对聚苯胺形貌和结构的研究,分析了聚苯胺的形成机理.而且对影响实验的参数,包括掺杂剂的种类,单体浓度,反应酸度进行了系统的研究.     

Preparation and microstructure of glass-ceramics and ceramic composite materials

The technology and microstructure of glass-ceramics and ceramic composite materials were studied. A suitable ceramic body was chosen on the basis of the sintering temperature of CaO-Al2O3-SiO2 system glass-ceramics. According to the expansion coefficient of the ceramic body, that of CaO-Al2O3-SiO2 system glass-ceramics was adjusted, fl-wollastonite was found present as the major crystalline phase in glass- ceramic. The CaO-Al2O3-SiO2 system glass-ceramic layer and ceramic body could be sintered together by adjusting the sintering period. The compositions of glass-ceramic layer and ceramic body diffuse mutually at 1 100 ℃, resulting in an interface between them. To achieve good sintered properties of glass-ceramics and the chosen ceramic body, at least a four-hour sintering time is used.     

Simulation and verification of machining deformation for composite materials

Prepreg properties including cure kinetics, cure shrinkage, and coefficient of thermal expansion were analyzed. A simulation method based on ＂element birth and death＂ method of Finite element analysis （FEA） was presented to simulate the cutting process and predict the machining deformation for composite laminates and stiffened panels. The comparisons between the simulation results and experimental data showed good agreement. It is found that residual stresses are the main source of machining deformation for composites and machining deformation is expected to happen only if there are stress gradients along the machining direction. There is no machining deformation for composite laminates due to its uniform stresses distribution in plane, while machining deformation can be observed obviously for T-shape stiffened composite panels. Attention should be paid to machining deformation to avoid the mismatch during assembly.     

粘弹性材料隔振性能的研究

本文讨论粘弹性材料的隔振性能和材料的物理因素、形状、尺寸之间的关系,分析了高低阻尼材料隔振性能各自的优缺点。在此基础上,首次从定量的角度,较为精确地分析了高低阻尼双层纵向(串联)复合、双层平等(并联)复合材料的隔振性能以及抑制驻波效应的方法。为了验证理论分析的正确性,分别对双层纵向、平行复合材料的隔振性能进行了测试,结果表明:理论分析结果和实验结果能较好地吻合,本文的分析方法比采用模态分析方法,用一阶或多阶模型来模拟材料隔振性能的方法更加精确、简便、直观,应用本文的方法,可以对粘弹性材料用于隔振时进行设计。     

新型大麻纤维复合材料的制备

采用大麻纤维下脚料、聚酯纤维和ES纤维作为原材料,在传统非织造布设备上采用热风法制备无纺毡,再对其进行热压成型制得大麻纤维复合型材,对ES纤维含量与成型工艺参数对型材力学性能的影响进行探讨．结果表明,随着ES纤维、成型温度和成型时间的增加,大麻纤维复合板材的拉伸强度和弯曲强度先增加后下降：大麻纤维复合板材的最优加工工艺为：ES纤维质量分数45％,成型温度195℃,成型时间6min．成型压力2．5MPa．     

New advances in fiber-reinforced composite honeycomb materials

In sandwich structures, lightweight cellular materials as the core hold the face sheets far away from the neutral axis to maximize the bending performance of the structure. Honeycomb materials as a major type of lightweight cellular materials have been widely applied in various fields, including aerospace, vehicle, marine, architecture and mechanical engineering, due to reliable mechanical properties and excellent designability. Using fiber-reinforced composites is an efficient method to develop ultralight honeycomb materials with superior mechanical behaviors. In recent years, fiber-reinforced composite honeycomb materials possessing lightweight and excellent mechanical performances have attracted noticeable attention to replacing traditional aluminum honeycombs and Nomex honeycombs. Compared to metal, polymer and Nomex paper, fiber-reinforced composites possess various merits, such as high specific stiffness and specific strength, excellent fatigue property, corrosion resistance and high-temperature resistance. Thus, the applications of fiber-reinforced honeycomb material for sandwich core have unlimited potential in hypersonic vehicles, long-range rockets, cargo vessels and protective systems. Although the fact that attention has been rapidly increasing, there is a lack of comprehensive reviews of new advances in the field of fiber-reinforced composite honeycomb materials. In this review, new advances reported by different scientists in the field of fiber-reinforced honeycomb materials have been reviewed and analyzed to provide an in-depth overview and knowledge for beginners in the field of ultralightweight and high-performance composite sandwich architectures. The challenges and prospects for the development of fiberreinforced honeycomb materials have also been presented.     

复合氧化物锰酸盐YMnO3和HoMnO3的水热合成及其结构表征

通过水热反应得到了YMnO3和HoMnO3两种钙钛矿复合氧化物,借助于ICP元素分析以及XRD和扫描电镜SEM对其结构进行了分析。结果表明,所得产物为RMnO3型的复合氧化物,并且化合物的结晶度好、纯度高,YMnO3为常见的六方结构化合物,而HoMnO3却表现出特殊的立方相结构特征,是一种亚稳态的结构。     

复合氧化物锰酸盐YMnO_3和HoMnO_3的水热合成及其结构表征

通过水热反应得到了YMnO3和HoMnO3两种钙钛矿复合氧化物,借助于ICP元素分析以及XRD和扫描电镜SEM对其结构进行了分析。结果表明,所得产物为RMnO3型的复合氧化物,并且化合物的结晶度好、纯度高,YMnO3为常见的六方结构化合物,而HoMnO3却表现出特殊的立方相结构特征,是一种亚稳态的结构。     

纳米材料的特殊性能及其应用

纳米材料因其独特的显微结构和组织形貌,使材料的物理、化学和机械性能发生了巨大的变化,极大地拓宽了材料的应用领域．叙述了纳米材料独特的显微结构、组织形态和物理、化学及机械性能,总结归纳了纳米材料的应用领域和发展前景．     

Properties and interfacial microstructure of cement-based materials with composite micro-grains

Silica fume, fly ash and nano-fiber mineral materials （NR powder） are employed to incorporate into cement-based materials. According to the grain grading mathematical model of cement-based materials, two packing systems, namely, spherical grading system and nano-fiber reinforced system were designed. Properties and interfacial microstructure of the two systems were studied according to secondary interface theory. It was shown that nano-fiber mineral materials can improve the grain grading of the admixture, increase the density of the system, improve the microstructure of the interface and the hardened paste, and enhance the uniformity of cement-based materials mixed with composite micro-grains and greatly increase their wearable rigidity and flexure strength. In this paper, two kinds of interface models, including spherical grain model and nano-fiber reinforced interface model of the cement-based materials mixed with composite micro-grains, were brought forward.     

Facile and controlled synthesis of silica sol nanospheres through a modified sol-gel process

An effective and reproducible preparation of silica sol nanospheres via a modified sol-gel process has been described. Monodisperse and stable silica sol nanospheres with uniformsize were successfully obtained through the optimized synthesis in which the mixture of tetraethyl orthosilicate （TEOS） and ethanol was followed by the addition of water and ammonium hydroxide （NH3） separately, and the size of silica sol spheres was strictly controlled in the range of 25-119 nm with a narrow size distribution by fine adjustment of several reaction parameters. Results showed that in the presence of low concentration of TEOS, spheres size rose first and reached maximum when H2O concentration was up to 66 g/L. However, the diameter of silica sol spheres decreased above 66 g/L of H2O concentration. Furthermore, it was also found that the size and size distribution of silica sol nanospheres were affected by NH3 concentration. As NH3 concentration increased from 15 to 35 g/L, the diameter declined from 83 to 64 nm. Nevertheless, higher NH3 concentration would result in relatively broad size distribution, and gelation occurred when NH3 concentration reached 44 g/L. In addition, the effect of the different feed rates ofNH3 on the size growth of silica sol nanospheres was also discussed.     

SnS/MWNT复合材料的制备及其超级电容器性

采用高能球磨法制备了SnS纳米颗粒,并同多壁碳纳米管MWNT组合得到SnS/MWNT复合超级电容器电极材料。运用X射线衍射和扫描电镜对SnS/MWNT复合材料进行了物相分析和形貌观察。对SnS/MWNT复合电极的循环伏安测试表明：随着SnS/MWNT复合电极中SnS的含量增大,SnS/MWNT复合电极的比电容逐渐增加。当SnS含量为80%时,比电容达到最大值62.5 F/g。恒流充放电测试中,不同配比SnS/MWNT复合电极的比电容在初始几个电化学循环中均有明显下降,随后保持良好的稳定性。同循环伏安结果一致,在SnS含量为80%时,SnS/MWNT复合电极的比电容最大。这主要归因于SnS在可逆氧化还原过程中产生的赝电容以及MWNT良好的导电性。     

How green composite materials could benefit aircraft construction

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