电弧法制备洋葱状富勒烯的工艺研究

运用纳米Bi2O3微粒作催化剂，在电弧放电条件下，进行了纳米洋葱状富勒烯大量合成的研究。并用透射电镜对产物的形貌、结构进行了观察与分析。结果表明：纳米洋葱状富勒烯的石墨化程度很高，且直径均匀(约为25nm)，结构较完善；同时伴有单核纳米洋葱状富勒烯向多核纳米洋葱状富勒烯的转变。为洋葱状富勒烯的宏量制备提供了有利线索。     

纳米金属微粒催化制备的洋葱状富勒烯的结构表征

采用金属Cu，Al做粒／石墨混合材料．用直流电弧放电方法制备了洋葱状富勒烯。对两种产物进行了XRD、SEM、HRTEM和Raman结构表征。结果表明：两种纳米金属微粒均可催化得到洋葱状富勒烯；所得产物中有单纯洋葱状富勒烯和内包纳米金属微粒洋葱状富勒烯，且石墨化程度都很高；纳米金属微粒尺寸大小不同决定洋葱状富勒烯的直径分布不均匀，从而造成其拉曼谱峰相对于石墨特征峰1582cm^-1发生了频移；用汽-液-固(VLS)生长模型描述了洋葱状富勒烯生长机理，解释了汽态碳原子通过在液态催化剂中扩散和析出，逐渐长大成形的现象。     

水下放电制备内包金属洋葱状富勒烯的研究

以二茂铁和纳米Ni粒子为催化剂,在水下放电条件下,制备了内包金属洋葱状富勒烯(Onion-like Fullerenes:OLFs),利用高分辨透射电镜(HRTEM)和X射线衍射(XRD)对所得产物进行了表征.结果表明:二茂铁和纳米Ni粒子均可催化得到内包金属洋葱状富勒烯,内包Fe洋葱状富勒烯直径分布在5～50nm之间,内包Ni洋葱状富勒烯直径分布在10～35nm之间.     

Fe/洋葱状富勒烯的化学修饰及润滑性研究EI北大核心

采用化学气相沉积(CVD)法制备了内包金属Fe/洋葱状富勒烯,利用高分辨透射电镜(HETRM)、X-射线衍射(XRD)和傅立叶红外(FT-IR)等对产物的结构和形貌进行了表征;运用硬脂酸对Fe/洋葱状富勒进行化学修饰;着重讨论硬脂酸修饰后Fe/洋葱状富勒烯作为润滑油添加剂的分散性和稳定性。结果表明所制备的Fe/洋葱状富勒烯颗粒均匀,通过酯化反应Fe/洋葱状富勒烯能够被硬脂酸包覆,显著提高了Fe/洋葱状富勒烯在润滑油中的分散性和稳定性。在MRS-10A型四球摩擦试验机上考察了Fe/洋葱状富勒烯作为机油添加剂的润滑性能。     

电弧放电条件下内包金属洋葱状富勒烯生成机理的研究

采用电弧法制备内包纳米金属微粒的洋葱状富勒烯.通过XRD、SEM和HRTEM对样品进行结构表征和分析,讨论影响纳米洋葱状富勒烯生成的因素.结果表明:可以宏量地制备内包金属微粒的NSOFs,且晶化程度很高;优化工艺参数可获得合适的气相温度及温度梯度,有利于NSOFs的生成;建立了汽-液-固(VLS)生长模型以解释其形成机理.     

纳米洋葱状富勒烯的研究进展及动向

评述了纳米洋葱状富勒烯的研究发展过程和动向，论述了该物质的各种制备方法及其工艺，并对各种制备工艺进行了分析和探讨性研究，在此基础上比较论述了每种方法的优缺点，展望了纳米洋葱状富勒烯基础研究，宏量制备和应用研究的发展趋向。     

碳纳米洋葱制备方法的研究进展

碳纳米洋葱是继富勒烯与碳纳米管之后的又一新型碳纳米材料,在润滑剂、磁性材料等领域具有广阔的应用前景.综述了碳纳米洋葱的主要合成方法(电弧放电法、等离子体法、电子束照射法、热处理法、热解法和化学气相沉积法)及其特点,讨论了碳洋葱的形成机理,并简单介绍了碳纳米洋葱的性能及其应用.     

重油残渣基新型碳功能材料的研究进展

综述了以重油残渣为原料,采用化学气相沉积法、共炭化法和微波等离子体法可控制备气相生长碳纤维、碳微球、内包铁洋葱状富勒烯、纳米碳管、内包金属碳微米颗粒及定向碳纳米薄膜等各种高附加值碳材料;采用等离子体氧化法、酸处理法、化学还原法等方法对气相生长碳纤维和碳微球进行表面修饰,在产物表面引入含氧官能团,解决了可溶性碳材料的制备问题;在碳微球表面引入Pt纳米颗粒,使重油残渣基新型碳材料在表面修饰和功能化后可望成为性能优异的吸附和催化材料.     

洋葱状富勒烯的研究进展

详细介绍和分析了洋葱状富勒烯(OLFS)的各种制备、纯化和改性方法,概述了其性能和应用的最新研究进展.OLFS特有的力、电、光、磁、吸附、催化等物理及化学性能,使其在工程、电子信息、能源、生物医学、化学化工、国防等领域有着广阔的应用前景.为此,应进一步围绕OLFS类新型纳米碳材料的制备、表面修饰、功能化、实际应用等各个环节的物理与化学问题进行探索,为该类功能材料的实际应用提供参考依据.     

催化剂种类对纳米洋葱状富勒烯形成的影响

研究了相同电弧放电条件下,不同催化剂(Fe、Al)掺杂对洋葱状富勒烯形成的影响.用高分辨透射电子显微镜(HRTEM)和X-射线衍射(XRD)对产物进行了观察与表征.结果表明,Fe作催化剂形成的洋葱状富勒烯产量和质量都优于Al作催化剂的情况,Fe的催化活性较Al的高,是制备洋葱状富勒烯的一种更加有效的催化剂.     

Structure,properties, and MEMS and microelectronic applications of vanadium oxides

Vanadium oxides have for many decades attracted much attention for their rich and unique physical properties which pose intriguing questions as to their fundamental origins as well as offering numerous potential applications for microelectronics, sensors, and microelectromechanical systems (MEMS). This paper reviews the unique structure and properties of the two most common vanadium oxides which have entered into microfabricated devices, VO₂ and V₂O₅, and some of the past and future device applications which can be realized using these materials. Two emerging new materials, sodium vanadium bronzes and vanadium oxide nanotubes are also discussed for their potential use in new microelectronic devices.     

金属-有机框架(MOFs)衍生材料及其在储能器件和电催化领域的应用

金属-有机框架(MOFs)是一类由金属离子/团簇和有机配体通过配位形成的具有多孔结构的无机-有机杂化材料。MOFs具有比表面积高、孔径均一、结构可调等优点,受到了人们的广泛关注。然而,MOFs的导电性和稳定性较差,制约了其应用的进一步拓展。以MOFs作为前驱体,通过水热反应或煅烧得到组成、形貌、结构可调的MOFs衍生材料,既能够保持MOFs材料结构多样性和多孔性的特点,又能有效提高其导电性和稳定性,近年来已成为该领域的研究热点。然而,MOFs衍生材料单一的组成和结构,使其能够提供的性能(如电容性能、催化性能)有限,极大地限制了其相关应用的发展。因此,近几年除了研究制备各种不同MOFs衍生材料外,研究者们主要从MOFs衍生材料的组成和结构方面出发,制备出多样化且在各方面应用中(如储能器件、催化)表现出优异性能的材料。MOFs衍生材料作为性能优异的应用型材料,其研究较为成熟的组成和结构分别主要包括多孔碳、金属氧化物、金属硫化物、金属磷化物、金属氢氧化物以及纤维状结构、中空结构、核壳结构等。MOFs衍生材料不仅具有高的比表面积、均一的孔径分布,通常还结合了衍生多孔碳的高导电性及其他衍生材料(金属化合物或掺杂的金属原子及杂原子,如N、P、S等)的优异性能(如电容性能、催化性能),从而发挥出更加优异的性能。其中,MOFs衍生金属化合物材料具备多孔结构,能够提供优异的容量性能及催化性能等,且其性能通常优于通过其他方法制备得到的同种材料。从结构方面出发,近几年,研究者们通过调控前驱体结构亦或是反应条件,制备得到多种不同结构的MOFs衍生材料。一方面,部分制备得到的结构(如核壳结构、中空结构)可以缓解MOFs衍生材料在使用过程中所受到的冲击,从而表现出优异的循环性能。另一方面,通过调控MOFs衍生材料的结构,使其活性位点得到充分的暴露,从而使其性能得到最大化的发挥。本文综述了MOFs衍生材料的研究进展,包括组成特点、结构调控,及其在储能器件、催化领域的应用,最后阐述了MOFs衍生材料研究领域当前面临的挑战以及未来的发展前景。     

氧化物热电材料研究进展

氧化物基热电材料具有高温稳定性、抗氧化性和安全长效等优点而受到人们的广泛关注, 但其应用受到了热电性能的限制。本文详细介绍了几种典型氧化物热电体系, 如层状钴基氧化物、钙钛矿结构化合物、透明导电氧化物和一些新型氧化物热电材料的研究进展。从能带结构和微观形貌两方面入手进行调节, 以达到热电材料热学性能和电学性能的协调统一。分析了氧化物热电材料研究中的主要问题, 并对未来的发展提出了一些新的思路。     

Auxetic materials — A review

Auxetic materials are endowed with a behavior that contradicts common sense, when subjected to an axial tensile load they increase their transverse dimension. In case of a compression load, they reduce their transverse dimension. Consequently, these materials have a negative Poisson’s ratio in such direction. This paper reviews research related to these materials. It presents the theories that explain their deformation behavior and reveals the important role represented by the internal structure. Their mechanical properties are explored and some potential applications for these materials are shown.     

Review of functionalization,structure and properties of graphene/polymer composite fibers

Fibrous materials usually have good mechanical, heat-resistant, acid-resistant, alkali-resistant and moisture regained properties which originate from its composition, condensed structure and crosslinking styles. However, these materials often lack of good electrical conductivity, flame retardance, anti-static and anti-radiation properties which are desired for varied specific applications. Graphene, as a new emerging nanocarbon material, has some unique properties including superb thermal and electrical conductivity, strong mechanical and anti-corrosive property, extremely high surface area etc. Therefore, graphene has attracted extensive interests in recent years. Upon modification with graphene, fibers exhibit a number of enhanced or new properties such as adsorption performance, anti-bacteria, hydrophobicity and conductivity which are beneficial for broader applications. In this review, the strategies to modify the fibers with graphene and the corresponding effects on the fibers as well as the relevant applications in varied areas were discussed.     

Properties of gasars-metallic materials with pores formed by released hydrogen

We developed a new type of porous materials with anisotropic structure based on a large number of metals. It is shown that these material, called gasars, have properties different from the properties of the other porous materials. Thus, the strength of gasars is much higher than the strength of powder materials with the same porosity and their impact toughness is readily regulated by the sizes of the pores. The internal structures of gasars and possible versions of the types of pores in these materials are strongly diversified, which makes the spectrum of their possible applications very wide. We discuss some specific directions of the potential applications of gasars. The results of measurements of the thermal conductivity of gasars and monolithic specimens are presented. It is shown that, for a certain level of porosity, the specific thermal conductivity of gasars is higher than for monolithic materials. We also make some basic conclusions concerning the characteristics of new porous materials. __________ Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 43, No. 5, pp. 125–127, September–October, 2007.     

Nano/Micro‐Manufacturing of Bioinspired Materials: a Review of Methods to Mimic Natural Structures

Through billions of years of evolution and natural selection, biological systems have developed strategies to achieve advantageous unification between structure and bulk properties. The discovery of these fascinating properties and phenomena has triggered increasing interest in identifying characteristics of biological materials, through modern characterization and modeling techniques. In an effort to produce better engineered materials, scientists and engineers have developed new methods and approaches to construct artificial advanced materials that resemble natural architecture and function. A brief review of typical naturally occurring materials is presented here, with a focus on chemical composition, nano‐structure, and architecture. The critical mechanisms underlying their properties are summarized, with a particular emphasis on the role of material architecture. A review of recent progress on the nano/micro‐manufacturing of bio‐inspired hybrid materials is then presented in detail. In this case, the focus is on nacre and bone‐inspired structural materials, petals and gecko foot‐inspired adhesive films, lotus and mosquito eye inspired superhydrophobic materials, brittlestar and Morpho butterfly‐inspired photonic structured coatings. Finally, some applications, current challenges and future directions with regard to manufacturing bio‐inspired hybrid materials are provided.     

石墨烯及复合材料作锂离子电池电极的进展

石墨烯是一种单原子层厚度的石墨材料,具有独特的二维结构和优异的电学、力学及化学稳定性。此外,石墨烯还具有特殊sp^2结构,易于与其它材料复合。利用石墨烯获得具有特殊形貌和微观结构的电极材料,能有效改善材料的各项电化学性能,作为锂离子电池的电极材料具有潜在的应用前景。总结了近些年对石墨烯及复合材料作为锂离子电池电极材料的研究,重点阐述了材料的制备、电学性质及基本原理,为其作为锂离子电极材料的应用提供相应的理论依据。     

Metallic glasses from “alchemy” to pure science: Present and future of design,processing and applications of glassy metals

Metallic glasses, first discovered a half century ago, are currently among the most studied metallic materials. Available in sizes up to several centimeters, with many novel, applicable properties, metallic glasses have also been the focus of research advancing the understanding of liquids and of glasses in general.Metallic glasses (MGs), called also bulk metallic glasses (BMGs) (or glassy metals, amorphous metals, liquid metals) are considered to be the materials of the future. Due to their high strength, metallic glasses have a number of interesting applications, for example as coatings. Metallic glasses can also be corrosion resistant. Metallic glasses, and the crystalline materials derived from them, can have very good resistance to sliding and abrasive wear. Combined with their strength – and now, toughness – this makes them ideal candidates for bio-implants or military applications. Prestigious Journals such as “Nature Materials”, “Nature” frequently publish new findings on these unusual glass materials. Moreover Chinese and Asian scientists have also been showing an interest in the study of metallic glasses.This review paper is far from exhaustive, but tries to cover the areas of interest as it follows: a short history, the local structure of BMGs and the glass forming ability (GFA), BMGs’ properties, the manufacturing and some applications of BMGs and finally, about the future of BMGs as valuable materials.     

Stimuli–Responsive Mechanoadaptive Elastomeric Composite Materials: Challenges,Opportunities, and New Approaches

Stimuli–responsive mechanoadaptive materials, capable of reversibly changing their mechanical properties when exposed to an external stimulus, are the next generation of smart materials with immense transformative potential for various technological applications. Although the concept of adaptive mechanical properties has been proven for some materials, it remains very challenging for soft elastomeric materials. The aim of this review is to provide new ideas and strategies for the development of mechanoadaptive elastomeric composites using commercial rubber as the matrix polymer. The fundamental question addressed here is as follows: How do the phase-responsive functional fillers alter the mechanical properties? For a given physical network environment, what is the mechanism that gives rise to the stimuli–responsive properties of the resulting composites? Herein, the preparation, structure, and properties of recently developed mechanoadaptive elastomeric materials are summarized. Furthermore, based on their structure–property relationships, plausible applications of these smart materials in various technology-specific applications such as soft robotics, actuators, sensors, smart tires, automotive design, aerospace, etc. are demonstrated with representative examples. Finally, the article critically discusses the existing challenges in the field of mechanoadaptive elastomers in order to provide valuable insights in this area.