Carbon
An efficient purification procedure for multi-walled carbon nanotubes (MWNTs) synthesized by the floating catalyst method was discussed. The process involves ultra-sonication, heat treatment in hot water, bromination, oxidation and acid treatment. Most of amorphous carbon, multishell carbon nanocapsules as well as metal particles were successfully removed from the MWNT product. With this procedure, MWNTs with purity of more than 94% were obtained and the yield could approach 50%. It was found that bromination took an important role in the purification of MWNTs. Transmission electron microscopy, XPS and thermo-gravimetric analysis were used to evaluate the purification process of MWNTs. The mechanism of bromination on purification of the MWNTs was also discussed. (C) 2002 Elsevier Science Ltd. All rights reserved.
关键词:
carbon nanotubes
C.G.Hu
,
W.L.Wang
,
W.Zhu
金属学报(英文版)
Wide potential windows were found at carbon nanotube film electrodes in neutral solutions after being treated with nitric acid and mixed acid. Electrochemical re-versibility was investigated at carbon nanotube films with different pretreatments for ferri/ferrocyanide and quinone /hydroquinone. Carbon nanotube film electrodes pre-sented quasi-reversible electrochemical behavior for both electrolytes. In the range of scan rate, carbon nanotube film electrodes treated with acids showed heterogeneous electron-transfer properties, which was mainly controlled by its electron state density on the surface of the film. On the whole, the carbon nanotube electrode with nitric acid treatment presented the best electrochemical behaviors, so we chose it as an analytical electrode to determine the trace compound in dilute solution. The results demonstrated that this new electrode material exhibits superior performance characteristics for the detection of azide anion.
关键词:
carbon nanotubes
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null
,
null
J.F.Dai
金属学报(英文版)
Well aligned quasi-straight single-walled carbon nanotubes (SWCNTs) and straight SWCNTs bundle have been prepared in large scale by anode-arc vaporization of graphite with metallic catalysts. Various parameters such as the catalyst preparation, the kinds and pressure of the buffer gases, the quantity of anode-arc current intensity, and the method of purification have been examined. The influence of these parameters on the deposited carbon yield is reported, together with observations of the produced material. Improvement in synthetic techniques has resulted in the optimal conditions for the production of large quantities of high quality SWCNTs in our semi-continuous synthesis method. The formation of carbon nanotubes (CNTs) was studied briefly in this paper Owing to the magnetic pinching effect of arc current, the CArTs arrange in parallel lines along the arc current direction.
关键词:
carbon nanotubes
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null
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null
Xiangwen Zhou Yuefeng Zhu Ji Liang Suyuan Yu
材料科学技术（英）
A novel technology to prepare styrene-butadiene rubber (SBR)/carbon nanotubes (CNTs) composites was developed by combining a spray drying method and a subsequent mechanical mixing process. The cross-linking degrees of the vulcanized composites increased gradually with the additive CNTs contents. By comparing with those of the pure SBR composites, the mechanical properties such as tensile strength, tear strength and hardness of the composites filled with CNTs at certain contents were dramatically improved almost by 600%, 250% and 70%, respectively. The fabrication of the CNTs filled with SBR composites by combination of the spray drying method and subsequent mechanical mixing process was effective for enhancing the reinforcement
effects of CNTs in rubbers. The novel technology can also open a new route for the modification and reinforcement on the nanocomposites with large amount of CNTs.
关键词:
Carbon nanotubes
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styrene-butadiene rubber
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spray drying
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mechanical mixing
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nanocomposite
,
mechanical property
石坚
,
卢秀萍
,
李红月
,
李东泽
复合材料学报
doi:10.13801/j.cnki.fhclxb.201503.004
为研究多壁碳纳米管(MWNTs)对聚乳酸(PLA)冷结晶动力学和球晶形态的影响,分别以PLA和表面包覆纳米SiO2并接枝硅烷偶联剂的纳米SiO2改性MWNTs(SiO2-MWNTs)为基体和改性剂,经溶液共混法制备了SiO2-MWNTs/PLA复合材料.采用DSC、偏光显微镜、Jeziorny模型和Johnson-Mehl-Avrami模型研究了复合材料的非等温冷结晶动力学和球晶形态.结果表明:SiO2-MWNTs可作为异相成核剂,能有效降低SiO2-MWNTs/PLA复合材料的冷结晶温度,提高晶核生成速率和晶体生长活化能.SiO2-MWNTs/PLA复合材料的冷结晶过程主要由成核作用控制,加入SiO2-MWNTs可同时提高复合材料的结晶速率和结晶度.冷结晶时,PLA球晶尺寸小于熔体冷却结晶时的,且SiO2-MWNTs含量对冷结晶球晶尺寸的影响远小于其对熔体冷却结晶球晶尺寸的.所得结论对优化PLA的结晶结构和性能、制备高性能PLA复合材料具有指导意义.
关键词:
聚乳酸
,
碳纳米管
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纳米SiO2
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包覆
,
冷结晶
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结晶动力学
,
球晶形态
欧忠星
,
郑玉婴
,
肖东升
,
曹宁宁
复合材料学报
doi:10.13801/j.cnki.fhclxb.20160309.004
为提高热塑性聚氨酯(TPU)的阻隔及抗静电性能,首先,向功能化改性还原氧化石墨烯(FRGO)中加入原始碳纳米管(CNTs),并通过非共价改性制得在N,N-二甲基甲酰胺(DMF)中均匀分散的杂化粒子FRGO-CNTs;然后,在涂膜机上通过溶液涂覆法制备了FRGO-CNTs/TPU复合材料膜;最后,利用FTIR、XRD、XPS、FE-SEM、TG、氧气透过仪、高阻计及万能试验机对FRGO-CNTs/TPU复合材料膜的结构和性能进行了表征.结果表明:FRGO与CNTs之间通过π-π共轭作用发挥协同效应,并且所制备的FRGO CNTs与TPU基体的相容性较好;当FRGO-CNTs含量(以TPU为基准)为2.0wt％时,复合材料膜的热分解温度提高了49℃,氧气透过率下降了53.7％;大比表面积的FRGO与高长径比的CNTs能在TPU基体中构建导电网络;当FRGO-CNTs含量仅为0.8wt％时,FRGO-CNTs/TPU复合材料膜的体积电阻率就能下降7个数量级.与此同时,随FRGO-CNTs含量的增加,复合材料膜的拉伸强度和断裂伸长率均先上升而后下降.
关键词:
功能石墨烯
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碳纳米管
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热塑性聚氨酯
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热稳定性
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阻隔性
,
抗静电性
,
力学性能
麻华丽
,
张新月
,
霍海波
,
曾凡光
,
王淦平
,
向飞
功能材料
doi:10.3969/j.issn.1001-9731.2013.16.026
采用酞菁铁高温热解方法在具有微立方结构的化学镀镍硅基底上生长了碳纳米管薄膜(Si/Ni-CNTs),并在20GW脉冲功率源系统中采用二板结构对其强流脉冲发射特性进行了研究.研究结果表明,在单脉冲发射条件下,随脉冲电场峰值的增大,Si/Ni-CNTs薄膜的发射电流峰值呈线性增加,当宏观场强达到31.4 V/μm时,发射脉冲电流的峰值可达到14.74kA,对应的发射电流密度1.23kA/cm2,在相同峰值,连续多脉冲情况下,碳纳米管薄膜具有良好的发射可重复性,且发射性能稳定.
关键词:
强流脉冲发射
,
碳纳米管
,
微立方阵列
,
线性增加
,
稳定性
刘奋成
,
贺立华
,
柯黎明
,
简晓光
,
刘强
稀有金属
采用搅拌摩擦加工法制备了不同体积分数碳纳米管增强AZ80镁基复合材料,考察了固溶+时效热处理对复合材料的微观组织和力学性能的影响.结果表明:镁基复合材料组织致密,晶粒细小,其中的碳纳米管均匀分布;热处理导致碳纳米管与AZ80基体界面上有Al3Ni2化合物生成,改善了界面结构;复合材料的抗拉强度随碳纳米管体积分数的增加逐渐增加,固溶+时效处理后的复合材料的抗拉强度有所提高,影响MWCNTs/AZ80复合材料力学性能的主要因素是碳纳米管与镁基体之间的界面结合情况.
关键词:
搅拌摩擦加工
,
碳纳米管
,
复合材料
,
热处理
卢志华
,
孙康宁
材料导报
利用原位合成法制备出羟基磷灰石/碳纳米管复合材料,采用XRD、TEM对其成分及结构进行了表征;采用MTT法和细胞形态分析研究了该复合材料对L-929细胞增殖活性的影响及细胞毒性反应,从而对其进行初步的生物相容性评价.结果表明,复合材料由羟基磷灰石和碳纳米管两相构成,纳米级的短棒状羟基磷灰石均匀吸附在碳纳米管表面,与之形成较强的界面结合;不同浓度的复合材料浸提液在不同时间点培养的细胞均正常增殖,其细胞毒性均在1级以下,符合国家医用生物材料的细胞毒性要求.
关键词:
羟基磷灰石
,
碳纳米管
,
复合材料
,
细胞毒性
