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碳纳米管复合材料制备及其性质研究

Study on Fabrication and Properties of Carbon Nanotube Composite Materials

【作者】 王策

【导师】 力虎林;

【作者基本信息】 兰州大学 , 物理化学, 2008, 博士

【摘要】 纳米材料具有很大比表面积,特殊的结构使得纳米材料具有独特的体积效应、表面效应、量子尺寸效应、宏观量子隧道效应,从而使其具有奇异的力学、电学、磁学、热学、光学、化学活性、催化和超导性能等特性,使纳米材料在国防、电子、化工、冶金、轻工、航空、陶瓷、核技术、催化剂、医药等领域具有重要的应用价值。碳纳米管(CNTs)具有完美的结构,是典型的一维纳米材料,它独特的物理结构,优异的性能和广阔的应用前景受到了人们的广泛关注。在一维方向上碳纳米管的强度可以超过钢丝,尽管CNTs的尺寸只有头发丝的十万分之一,但是它的杨氏模量理论强度可以达到1.0TPa,是钢的100倍,同时它的密度却仅为钢的六分之一到七分之一。CNTs的熔点是已知材料中最高的,它的硬度可以和金刚石相媲美。碳纳米管有超高的韧性,可以拉伸,其韧性理论最大延伸率可达20%。CNTs化学性质稳定,耐强酸、强碱,在空气中700℃以下基本不氧化。这些优点使得碳纳米管作为纳米材料中最具潜力的材料之一,被认为是纳米材料的理想添加相。但是,通常碳纳米管不溶解不熔融也不易加工,作为一种纳米尺寸的材料还极易发生团聚,使其进一步开发与应用受到很大的限制。因此对碳纳米管进行改性和应用研究引起人们浓厚的兴趣。科学家们目前在实验室中将其作为增强体来大幅度提高材料的强度或者韧性等力学综合性能;或利用其良好的电学性能和磁学性能,将其作为改性体来大幅度提高材料导电性、电磁屏蔽性能和光电子发射性等。碳纳米管不仅具有优异的力学性质、电学性质,能大幅度提高掺杂有碳纳米管复合材料的抗冲击、提高剪切能力,提高复合材料的导电性外,还能够有效地促进生物物质,(如蛋白质,多巴胺)、环境物质的电子传递,近年来,有关碳纳米管的电化学活性机理与其形态结构、制备方法和表面修饰等方面的研究也日益受到人们的关注。目前,国内外纳米材料的研究和应用已经有了很大的进展,但距离工业化生产和大规模普及应用还有一定距离。本文综述了当前碳纳米管纳米复合材料的最新研究进展,紧紧围绕碳纳米管纳米复合材料这个当前研究热点,重点做了三个方面的研究:对CNTs进行化学改性后研究其与丙烯腈系列树脂共聚,制备碳纳米管-丙烯腈系列复合材料,并研究其摩擦学和显微硬度性质;利用CNTs能有效促进生物物质的电子传递特性,将CNTs进行酸化处理后复合在玻碳电极上来测量对多巴胺催化的;利用CNTs大的比表面积和纳米粒子的表面效应、量子效应和小尺寸效应,在碳纳米管表面可控性沉积纳米尺寸的金属银粒子以期获得理想的金属-CNTs复合材料。本论文的主要研究内容:1、对多壁碳纳米管进行了酸化处理,经过拉曼光谱表征,多壁碳纳米管的特征强峰出现在1580cm-1处,说明多壁碳纳米管的结构并未受到破坏。经傅里叶红外光谱表征,在碳纳米管红外光谱图上出现了1736cm-1左右的羧基特征峰,1601 cm-1处的羰基特征峰和1211cm-1左右的羟基面内弯曲振动峰。说明CNTs经纯化和活化处理后,在其管壁上已经接上了羟基(-OH),羰基(>C=0)和羧基(-COOH)这些功能性官能团。2、采用原位复合法,对丙烯腈-苯乙烯(AS)进行改性,得到复合效果良好的丙烯腈-苯乙烯-CNTs(AS-CNTs)共聚物纳米复合材料。经过对其摩擦学性质和显微硬度测试,发现掺杂CNTs的AS系列复合材料的摩擦学性质和显微硬度都有不同程度的提高,掺杂1.5%CNTs的复合材料表现有最佳的综合性能。经FE—TEM电镜对AS和AS—CNTs的磨痕进行观察,发现掺杂有CNTs的纳米复合材料的磨痕的相对于未掺杂的AS磨痕,其磨痕明显地浅,而且光滑、整齐。3、用甲基丙烯酸甲酯(AMMA)对丙烯腈进行改性,再掺杂CNTs,测试其摩擦学性质和显微硬度,用电镜观察其结构得到与用苯乙烯改性丙烯腈类似的结果。4、对AS树脂进行改性,复合进甲基丙烯酸甲酯,结果得到透明的改性材料AMS,再复合进CNTs,测试其摩擦学性质和显微硬度,发现均有不同程度的提高。5、利用碳纳米管对生物物质具有支持电子传递的性质,将碳纳米管进行氧化处理,然后用nafion复合在玻碳电极上,在多种环境中测量对多巴胺(DA)催化的灵敏度,发现在多种环境和干扰物质(UA和AA等电位反应相近的神经递质)存在下,电极响应具有很高的灵敏性和选择性。6、利用碳纳米管具有大的比表面积的特性,期望将纳米金属颗粒负载于CNTs表面,设计出催化效率更为高效的纳米型催化复合材料。本实验经过研究,设计出一个方便快捷的实验方法,利用苄醇可以方便地、可控地将银离子负载于CNTs的表面。经过红外、紫外、XRD、TEM等表征手段表征,发现还原沉积在CNTs表面的金属银粒子具有很好的纳米尺寸。

【Abstract】 The unique volume effect,high surface effect,quantum size effect and macroscopical quantum tunnel effect of nanomaterials was due to their special structure.These characteristic effect bring nanomaterials the special mechanics, electronics,magnetics,calorifics,optics,chemical active,catalyst and superconduction peculiarity etc.The unique characters result in its important application in many fields including national defence,electronic engineering, chemical,metallurgy,light industry,aviation,china,nucleus,catalyst,medicine and so on.Carbon nanotubes(CNTs) is the typical one-dimensional(1D) nanomaterial which possess perfect structure.Owing to its special physical structure,outstanding performance and wide application,CNTs has been paid great attention.The intensity of CNTs could exceed steel wire in 1D bearing.Though dimension of CNTs only 1/100000 of one hair,the average value of Young’s modulus of isolated MWNTs has been measured to be 1.0 TPa.The tensile strength of CNTs are up to 100 times stronger than steel,while its density is one-sixth to one-seventh that of steel.The melting point of CNTs is the highest in the materials as known,while its hardness similar to diamond.CNTs possess the supertenacity which make it could be pulled,and the most tenacity could reach 20%of itself in theory.The chemical character of CNTs is very stable which could endure the violet acid,violet alkali and don’t be oxidated below 700℃in air.Combining with the above factors,CNTs are believed to be the ideal and limited type materials for nanocomposites,and can be used to make excellent composites with remarkable performance.But,CNTs is easy to agglomerate due to their high surface energy,which make the application of CNTs limited.So,it is very hot that study the alterperformance and application of CNTs.Scientists take CNTs as the increase matter to increase the intensity and tenacity or mechanical capability of the composites in laboratories at present.Also they take the excellent electronic capability and magnetic performance as the medium to enhance material character of the electric,electromagnetism shield and photoelectron emanative performance and so on.Owing to the excellent character of mechanics and electronics,not only CNTs could enhance the intensity,tenacity and conduction of the nanocomposites-CNTs,but also could it promote the electron transfer in the biology substance,(for example protein,dopamine) and environment substance.Recentlly people have paid great attention to the study of electrochemical mechanism,conformation structure, preparation method and surface modify of CNTs.At present,the study and application about nanomaterials have achieved greatly in the world.But there is still a long way for its commercial production,popularization and application on a large scale.In this paper,we reviewed the latest development in the research of CNTs nanocomposites.Focusing on the CNTs nanocomposites,we have investigated three studies,which include fabricating a series of acrylonifrile-CNTs nanocomposites and studying their tribological property and microhardness,taking CNTs/GCE as the check measure to detect dopamine due to the performance of CNTs to promote the electron transfer effectly in the biology substance,and depositing highly monodispersed Ag nanoparticles onto CNTs surface controllablly because of the high surface area and surface effect,quantum size effect and small size effect.The main research of this thesis is as following:1、After acidification,multi-walled carbon nanotubes showed characteristic absorption bands(1580cm-1) in the Raman Spectrum,which reveals that its structure was not damaged.And the FTIR spectrum reveal showed three absorption bands for carboxyl group(1736cm-1),carbonyl group(1601 cm-1) and in-plane bending vibration(1211cm-1) of hydroxyl group.Then we can conclude that the walls of CNTs by proceeding purification and activation have been attached successfully to hydroxyl,carbonyl and carboxyl functional group.2、by means of in situ polymerization method,we have produced polyacrylonifrile-styrene(AS) copolymer and polyacrylonifrile- styrene-CNTs nanocomposites.(AS-CNTs)After disscusing the influences of the content of CNTs, microhardness and dispersion degree on the friction and wear properties of nanocomposites,we discovered that the complex with 1.5%content of CNTs showed the best integrated performance and the worn surface was smooth,uniform and compact relatively.3、Polyacrylonifrile-methylmethacrylate(AMMA) mixed with different carbon nanotubes(CNTs) fractions(AMS-CNTs) have been successfully prepared by means of in situ polymerization method.The result as similar as AS.4、We have prepared the polyacrylonifrile-methylmethacrylate-styrene(AMS) mixed with different carbon nanotubes(CNTs) fractions(AMS-CNTs) successfully by means of in situ polymerization method.After investigating the tribological property and microhardness,we got the better experiment results.5、We detected dopamine with o-MWNTs/GCE in many environments because CNTs could promote the electron transfer in the biology substance.The detected result is very sensitive and selective.6、Owing to their hollow structure and high surface area of CNTs,we expect to get the more efficient nanocomposites Catalyst through depositing metal particle onto CNTs surface.After investigation,we designed a simple way to come true the assume. The as-synthesized composites were characterized by transmission electron microscopy(TEM),X-ray diffraction(XRD) and ultraviolet-visible absorption spectrometry(Uv-vis).The synthesis method provided a flexible route for preparation of novel metal/CNTs hybrid materials.

  • 【网络出版投稿人】 兰州大学
  • 【网络出版年期】2009年 12期
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