超薄类石墨相氮化碳纳米片剥离技术的研究进展

超薄二维（2D）纳米材料,因其优异的电子、光学、物理和化学性能,以及各种潜在应用,在纳米技术、材料科学、化学和凝聚态物理等领域迅速发展. 类石墨相氮化碳（g-C₃N₄）是一类主要由碳和氮原子组成的2D聚合物材料,但块状g-C₃N₄比表面积小、分散性差严重影响其在光催化领域的应用. 因此,人们常采用剥离方法制备超薄g-C3N4纳米片. 本文主要详述了目前常用的热氧化剥离、超声辅助液相剥离和酸碱化学剥离等方法的现状及机理,并讨论了超薄g-C₃N₄纳米片未来的重点研究方向.     

Cl 掺杂提升N-PbS 热电性能的实验研究

铅基硫属化合物在中高温热电领域具有广泛的应用。相较于Te 和Se 元素, S 元素具有含量丰富, 价格低廉,且PbS 热稳定性高等优点, 近年来PbS 热电材料引起了研究人员的广泛兴趣。然而, PbS 热电材料本体固有高晶格 热导率, 导致其较低的热电转化效率, 严重限制了其在热电领域的应用。为了降低其晶格热导率, 采用Cl 掺杂方法改善PbS 的热电性能。实验结果表明, 通过水热法制备了形貌可控的树枝状PbS 基纳米材料, 在烧结过程中形成了 多孔结构PbS 基块体材料。通过测试结果可知, Cl 掺杂后的多孔PbS 材料的致密度和晶格热导率显著降低, 载流子浓度升高, 热电性能明显改善, 其中PbCl_0.02S_0.98 材料在773 K 时zT 值达到0.71, 较纯PbS 提升了约108.8%。     

Electronic structures and properties of V, Nb and Ta metals

0　ＩｎｔｒｏｄｕｃｔｉｏｎＴｏｄｅｓｉｇｎａｌｌｏｙｓｓｃｉｅｎｔｉｆｉｃａｌｌｙ ,ｓｙｓｔｅｍａｔｉｃｓｃｉｅｎｃｅｆｒａｍｅｏｆｍｅｔａｌｓａｎｄａｌｌｏｙｓｉｎｃｌｕｄｉｎｇｔｈｅｓｙｓｔｅｍａｔｉｃｓｃｉｅｎｃｅｏｆｐｕｒｅｍｅｔａｌｓ (ｏｎｅ ａｔｏｍ (ＯＡ)ｔｈｅｏｒｙ) [1,2 ]ａｎｄｔｈｅｓｙｓ ｔｅｍａｔｉｃｓｃｉｅｎｃｅｏｆａｌｌｏｙｓ (ｃｈａｒａｃｔｅｒｉｓｔｉｃｃｒｙｓｔａｌ(ＣＣ)ｔｈｅ ｏｒｙ) [3～ 6 ]ａｒｅｅｓｔａｂｌｉｓｈｅｄ ,ｗｈｉｃｈｃａｎｇｉｖｅｄｉａｇｒａｍｓｏｆ…     

碳纳米管超晶格结构的第一性原理

针对掺杂N、B、Si的碳纳米管超晶格的电子结构及拉伸性能,运用第一性原理进行了相关研究.结果表明,碳纳米管超晶格会形成类似管状结构.不同掺杂元素导致碳纳米管超晶格的结构稳定性有所不同.碳纳米管经掺杂后,能带中的能隙由半导体性转变为金属性,且费米能级处的态密度值增大,表明碳纳米管超晶格的物理化学活性增强,而结构稳定性降低.对于碳纳米管超晶格而言,结构稳定性从高至低依次为3×1碳氮、1×1碳硼和3×1碳硼纳米管超晶格.     

Evaluation and Characterization of Mechanical, Electrical, and Thermal Properties of Polymer Nanocomposites Reinforced with Different Allotropes of Carbon

The present work aims to present the results based on the processing of nanocomposites, which consist of matrix materials like epoxy and filler materials such as conjugated nanomaterials/allotropes of carbon, namely, carbon black, graphite, and multiwalled carbon nanotube (MWCNT) used for targeted applications. To improve the physical and chemical properties and to facilitate a better interfacial interface between the polymer and nanotube, functional MWCNT is used during the preparation of the composite. The prime objective of the study is to establish the thermal, mechanical, and electrical properties of nanocomposites using experimental methods. It has been observed from the experimental results that carbon nanotube (CNT) based composite exhibits higher mechanical (tensile and hardness) and thermal properties as compared with the others. The electrical properties are found to be better in a graphite-based composite. Although CNT has superior mechanical and thermal properties, the exorbitant price limits its use. Hence, the allotropes of carbon may be used judiciously considering both the cost and property requirements of the targeted application. The work also studies the dispersion state of nanofibers through scanning electron microscopy (SEM).     

Research on the electronic transport characteristics of the three-dimensional graphene/carbon nanotube composite structure

According to the actual growth way of graphene presence of the carbon source, four kinds of 3d grapheme-carbon nanotubes composite T structure are built, and their electron transport properties studied by combining density functional theory and the non-equilibrium green's function method. First the double probe model is built and the structure optimization is designed in ATK software, and then their transmission spectrums and electronic state density spectrum lines are analyzed. These research results can provide the reference for the 3d interconnect based on carbon nanomaterials.     

Fabrication and Microstructure of BN Matrix Composites with Electrical COnductivity

BN ceramic is advanced engineering ceramics with excellent thermal shock resistance,good workability and excellent dielectricity.TiB2 ceramic has excellent electric conductivity,high melting points,and corrosion resistance to molten metal.Therefore,the composite consisting of BN and TiB2 ceramics is expected to have a combination of above-mentionaed properties,thereby can be used as self-heating crucible.In this puper,hot pressing technology was used to fabricate the high performance BN-TiB2 composite materials,microstructure and electric conducting mechanism were studied,and the relationship between the microstructure and physical property was discussed.the results show that the microstructure of composites has a great influence on the physical property of composites.The BN-TiB2 composites with excellent mechanical strength and stable resistivity can be obtained by optimizing the processing parameter and controlling the microstructure of composites.     

富镍三元正极材料的改性研究进展

随着便携式电子产品和电动车领域的高速发展,对高能量密度锂离子电池的性能提出了更高的要求。相比传统的钴酸锂正极材料,富镍层状金属氧化物具有较高能量密度和较低的原料成本,被视为理想的锂离子电池正极材料。然而,其结构缺陷和不稳定的表面化学特性会恶化材料的电化学性质、热力学稳定性和安全性能。本文主要回顾了近年来关于富镍三元正极材料的改性研究进展,旨在为今后富镍三元正极材料的设计提供重要思路,并实现其工业化应用。首先,介绍了富镍正极材料本身存在的固有缺陷和电化学性能衰减机制。然后,讨论了通过调控界面结构提升富镍材料性能的改性策略,包括包覆电化学惰性物质、设计元素全浓度梯度及核壳结构、构筑核壳异质结构和调控包覆物质厚度等。再然后,总结了通过元素的体相掺杂提升富镍正极材料性能的策略,包括碱金属位掺杂、过渡金属位掺杂、氧位掺杂和复合共掺杂。最后,我们对该领域的未来发展进行了总结和展望,希望能激发更多创新性的见解和策略,以促进富镍三元正极材料的实际应用。     

选区激光熔化3D打印钛合金及其复合材料研究进展

综述：生物医用铁基磁性纳米颗粒的制备研究进展

毛宇,李艳,顾宁

（东南大学 生物科学与医学工程学院,江苏省生物材料与器件重点实验室,生物电子学国家重点实验室,南京 210096）

摘要：磁性纳米材料具有独特的物理性能、化学性能以及生物效应,是一类重要的功能材料,可以应用于很多领域。在过去的几十年,铁基磁性纳米材料由于其优越的磁性能和巨大的生物医用潜力在生物医学领域引起了大量的关注。特别是具有诊断和治疗功能的磁性氧化铁纳米颗粒一直在生物医学领域发挥着重要作用。磁性氧化铁纳米颗粒是良性的、低毒的、生物相容且生物可降解的,是目前美国食品及药物管理局批准的唯一可用于临床的无机磁性纳米材料。本综述主要介绍了生物医用铁基纳米材料包括铁单质纳米颗粒、铁基合金纳米颗粒及磁性氧化铁纳米颗粒的制备研究进展,重点介绍了磁性氧化铁纳米颗粒的制备方法,并总结指出了磁性氧化铁纳米颗粒制备方法发展的重要性。

关键词: 铁基磁性纳米材料;生物医用;磁性氧化铁纳米颗粒;诊断和治疗功能;制备方法

     

Structures and properties of Sc and Y metals

Ａｔｒｏｏｍｔｅｍｐｅｒａｔｕｒｅａｎｄａｍｂｉｅｎｔｐｒｅｓｓｕｒｅ ,ｔｈｅｓｔａ ｂｌｅｃｒｙｓｔａｌｌｉｎｅｓｔａｔｅｏｆＳｃａｎｄＹｈａｓａｈｅｘａｇｏｎａｌｃｏｌｓｅ ｐａｃｋｅｄ(ｈｃｐ)ｓｔｒｕｃｔｕｒｅ(αｐｈａｓｅ) .Ａｔｈｉｇｈｔｅｍｐｅｒａｔｕｒｅ ,ｂｏｔｈｍｅｔａｌｓｕｎｄｅｒｇｏａｐｈａｓｅｔｒａｎｓｆｏｒｍａｔｉｏｎｉｎｔｏａｂｏｄｙ ｃｅｎｔｅｒｅｄｃｕｂｉｃ(ｂｃｃ)ｓｔｒｕｃｔｕｒｅ( βｐｈａｓｅ) .Ｔｈｅｐｈａｓｅｓｔａ ｂｉｌｉｔｙａｎｄｐｈａｓｅｔｒａｎｓｆｏｒｍａ…     

碳纳米管/羧甲基纤维素钠杂化材料修饰电极的制备及其电化学性能研究

伴随着纯电动汽车、利用清洁能源的高效储蓄和便携式电子产品的飞速发展,寻找具有高功率密度、低成本、高可靠性、环保且寿命长的新型电化学储能材料与器件迫在眉睫.纤维素是一种自然形成的有机聚合物,其自身良好的生物相容性和可降解性使其在新能源材料应用上备受关注.近年来,天然纤维素微纳化与新型纤维素衍生材料制备的工程化,显著扩大了纤维素基材料在新能源领域的应用范围.通过杂化、物理共混、化学改性、掺杂与互穿等方式,构建与制备纤维素基高性能绿色环保储能材料具有理论研究价值和应用潜力.将羧甲基纤维素钠作为碳纳米管的分散剂构建杂化体系,使碳纳米管的电化学性能得以充分发挥,通过对溶剂配比、PH酸碱度等影响因素的探索,得到制备电化学性能优异的杂化体系的最佳实验条件,该杂化体系修饰后的电极材料具备构建超级电容器的巨大潜力.     

碳纳米管自组装的研究进展

通过分子自组装,碳纳米管可结合成具有不同功能的碳纳米管复合材料,从而可进一步设计成具有特殊结构和功能的纳米材料,在医学、组织工程及生物材料等方面有着巨大的应用潜力.本文主要综述了碳纳米管自组装纳米材料的研究现状与制备方法,重点介绍了通过化学吸附自组装、静电自组装、模板自组装、静电力及氢键、亲水/疏水相互作用和DNA操纵下的自组装,并对各种方法的特点及研究现状进行了评述.     

Nanoimprint lithography for the manufacturing of flexible electronics

Flexible electronics have received considerable attention in academies and industries for their promising applications in enormous fields, such as flexible displays, wearable sensors, artificial skins, and flexible energy devices. Challenges remain in developing a flexible and scalable manufacturing method to facilitate the fabrication of multi-functional structures in a flexible electronic system. Nanoimprint lithography is a high resolution and low-cost approach to fabricate nanostructures over a large area. This paper reviews recent progress of nanoimprint lithography and its applications in flexible electronics. The basic principles, classification, research focus, and critical issues of nanoimprint lithography are elaborated. Then, the advantages of nanoimprint lithography are demonstrated in several typical applications related to flexible electronics, including conductive films, optoelectronic devices, flexible sensors, energy harvesting and storage devices, and bioinspired electronic devices. Finally,the challenges and perspectives of nanoimprint lithography in flexible electronic systems are discussed.     

Low temperature doping of ZnO nanostructures

Doping of ZnO nanostructures was investigated by using a low temperature electrochemical process. Various dopant materials have been studied, including transition metals, group I, and group VII elements. The structure, composition, and optical properties of the doped ZnO nanostructures were analyzed by scanning electron microscopy, energy dispersive X-ray spectroscopy, photoluminescence, and x-ray diffraction. It was demonstrated that dopant elements were incorporated into the ZnO structures. The effects of dopant incorporation on the structure and properties of ZnO were also investigated. This low temperature approach is compatible with current micro-fabrication techniques and promising for large-scale production of doped ZnO nanostructures for optical and electronic applications.     

Effects of Microstructure Modification on Properties of AIN/BN Composites

It is very difficult to prepare full-densified aluminum nitride-boron nitride(AIN/BN)composite ceramics with homogeneous microstructure and high thermal conductivity.Spark plasma sintering(SPS)was used to fully densify the AIN/BN composites in this work.Microstructure,mechanical properties and thermal conductivity of the SPS sintered AIN/BN composites with 5-30 vol% BN were investigated.The results show that the microstructure of composites is fine and homogenous,and the AIN/BN composites exhibit high mechanical properties.To promote the growth of AIN grains and modify the distribution of grain boundary in AIN/BN composites,a heat treating methodology was introduced through gas pressure sintering(GPS).This processing was significantly beneficial to enhancing the thermal conductivity of the specimen.The thermal conductivity of AIN/BN composites with 5-30 vol% BN reached 60 W/m K after the samples were treated by GPS.     

Effects of Mierostructure Modification on Properties of MN/BN Composites

It is very difficult to prepare full-densified aluminum nitride-boron nitride(AIN/BN) composite ceramics with homogeneous microstructure and high thermal conductivity.Spark plasma sintering (SPS)was used to fully densify the AlN/BN composites in this work.Microstructure,mechanical properties and thermal conductivity of the SPS sintered AIN/BN composites with 5-30 vol% BN were investigated.The results show that the microstructure of composites is fine and homogenous,and the AIN/BN composites exhibit high mechanical properties.To promote the growth of AlN grains and modify the distribution of grain boundary in AIN/BN composites,a heat treating methodology was introduced through gas pressure sintering(GPS).This processing was significantly beneficial to enhancing the thermal conductivity of the specimen.The thermal conductivity of AIN/BN composites with 5-30 vol% BN reached 60 W/m K after the samples were treated by GPS.     

面向平板结构钙钛矿太阳能电池的金属氧化物综述

作为平板结构钙钛矿太阳能电池的电荷传输层，金属氧化物薄膜对器件性能有重要影响. 系统性概述平板结构钙钛矿太阳能电池对金属氧化物薄膜形貌、电学、光学、化学及热等物理特性要求，并对目前在高效钙钛矿太阳电池制备中最有前景的金属氧化物电子传输层及空穴传输层材料特性及代表性工作进行总结. 针对大多数金属氧化物迁移率低、表面缺陷多及能级匹配差的问题，分析元素掺杂、表面改性、复合薄膜设计等手段解决的相关进展. 总结目前金属氧化物薄膜沉积技术现状及优缺点，探讨今后薄膜沉积技术发展、改进方向. 对低温沉积金属氧化物薄膜在柔性器件方面的应用进行展望.     

Catalytic CVD Growth of Carbon Nanotubes by Electric Heating Method

Carbon nanotubes(CNTs) were synthesized by the electric heating catalytic chemical deposition method(CCVD) using acetylene(C_2H_2) as the carbon source and nitrogen(N_2) as carrier gas,and nickel catalyst was loaded by electroplating.The electric heating method,as a new method,electrifies the carbon fiber directly by using its conductivity.The morphology and structure of CNTs were characterized by SEM and TEM,and the surface properties of carbon fibers before and after the growth of CNT were characterized by Raman spectroscopy.The experimental results show that the electric heating method is a new method to produce CNT,and can grow a large number of CNTs in a short time,the crystallization degree and surface average crystallite size of carbon fiber increased after the growth of CNT on it.In addition,electroplating loading catalyst can also be used as an ideal loading way,which can control the number,shape,and distribution of nickel particles by controlling the plating time.     

环氧树脂/碳纤维导热复合材料研究进展

为提高碳纤维复合材料的导热、老化以及其他力学性能,本文探讨了以环氧树脂为基体,以具有优良的力学性能的碳纤维为导热载体,制备具有良好性能的导热复合材料的制备工艺。同时,研究了碳纤维增强环氧树脂基体的热传导机制,以及近些年来环氧树脂基导热复合材料的科研现状。     

Microstructure and Properties of A IN Coating/Graphite Fabricated via In-situ Reaction

A novel method was used to fabricate AIN coating on graphite substrate.This approach included two steps:firstly,the emulsion composed of BN and anhydrous ethanol was sprayed on the surface of the graphite substrate;secondly,AIN coating was formed through the in-situ reaction of Al with the sprayed BN.The reaction was investigated by thermogravimetric-differential thermal analysis(TG-DTA),and the phase composition in the synthetic process was characterized by X-ray diffraction(XRD).Scanning electronic microscopy(SEM)was used to observe the morphology,and electron probe microanalysis(EPMA)was used to observe the distribution of the elements.The experimental results show that the AIN coating is dense and bonded with graphite tightly.