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利用膨化石墨原位气相沉积制备多层石墨烯/碳纳米管复合粉体。以膨胀石墨为基体,以硝酸铁、碳酸铵等物质对其进行修饰,结合化学气相沉积工艺,原位制备出多层石墨烯/碳纳米管复合粉体材料;探讨不同的修饰液相对复合粉体比例,微观形貌及分散性的影响。利用扫描电镜对复合粉体进行表征。结果表明:多层石墨烯/碳纳米管复合粉体材料可批量制备;其中多层石墨烯为透明薄片,其厚度为10~30nm;通过控制工艺参数,可以实现多层石墨烯的质量比为15%~50%;复合粉体中碳纳米管的分散性明显优于一般化学气相沉积方法制备的碳纳米管;加入质量分数5%复合粉体的聚对苯二甲酸丁二醇酯(PBT)的表面电阻显著降低。 相似文献
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以膨胀石墨为基体,用硝酸铁、碳酸铵等物质对其进行修饰,结合化学气相沉积工艺,原位制备出石墨烯/碳纳米管复合粉体材料;利用扫描电镜对复合粉体进行了表征。采用熔融混炼的方法制备PBT/石墨烯/碳纳米管复合材料并测试了其表面电阻。研究结果表明:该方法可以制备出性能优异的石墨烯/碳纳米管复合粉体材料,将该复合粉体加入到PBT中所制备的复合材料具有优良的电性能;当复合粉体加入量为5%时,PBT/石墨烯/碳纳米管复合材料的表面电阻可达到106Ω。 相似文献
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采用表面活性剂和超声辅助的混酸处理工艺对碳纳米管进行了表面修饰,均获得了分散均匀的碳纳米管悬浮水溶液,利用傅立叶红外吸收光谱及Zeta电位等手段对其分散机理进行了分析;采用快速溶胶一凝胶法,制备了多种碳纳米管含量的石英基复合粉体,透射电镜观察显示两种修饰碳纳米管表面的方法都有效提高了碳纳米管在石英基体的分散性,制备出了均匀的碳纳米管/石英复合粉体。 相似文献
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采用液相还原的方法,在碱性环境下使用FeCl2.4H2O和氧化石墨作为前驱体,制备Fe3O4微球附载的石墨烯复合材料。通过调节氧化石墨和铁盐的质量比制备得到不同组分的Fe3O4/石墨烯复合粉体。使用场发射电子扫描显微镜(FESEM)、X射线衍射仪(XRD)、振动样品磁强计(VSM)和四探针电阻仪等仪器分析了产物的形貌、物相、磁性能和导电性能。结果表明Fe3O4/石墨烯复合粉体中Fe3O4微球在石墨烯表面分散均匀,且Fe3O4结晶良好,为立方晶系的尖晶石型。该复合粉体具有高的磁性能和良好的导电性能,饱和磁化强度和电导率分别达到72emu/g和0.53S/cm。 相似文献
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以化学气相沉积(CVD)法制备的石墨烯和碳纳米管的邻二氯苯分散液为原料, 采用滴涂法制备石墨烯/碳纳米管复合薄膜, 用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、拉曼光谱(Raman)和X射线光电子能谱(XPS)对其形貌和结构进行表征。实验发现随着碳纳米管分散液浓度的增大, 复合薄膜结构中碳纳米管的面密度线性增大。利用紫外-可见光谱仪和四探针测试仪表征了不同碳纳米管浓度下复合薄膜的透光率及其薄层电阻, 结果表明: 随着碳纳米管浓度的增大, 复合薄膜的透光率及其薄层电阻都将减小, 当碳纳米管浓度为0.1 mg/mL时, 复合薄膜的透光率(550 nm)及其薄层电阻分别为92.18%和0.998 kΩ/□。实验通过调节碳纳米管浓度制备得到不同性能的石墨烯/碳纳米管复合薄膜, 该复合薄膜在透明电极、场效应晶体管和激光锁模等方面具有潜在应用。 相似文献
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采用干湿法纺丝工艺制备氧化石墨烯/聚酰亚胺复合纤维,然后将复合纤维进行炭化和石墨化处理得到石墨烯/聚酰亚胺复合碳纤维及石墨纤维。对复合碳纤维进行热重分析、Raman、力学性能、传导性能、形貌等测试分析。结果表明,氧化石墨烯添加量为0.3%(质量分数,下同)的复合纤维的耐热性能最佳;氧化石墨烯的加入,使石墨烯/聚酰亚胺复合碳纤维的力学性能和传导性能明显提高,石墨化程度增加。当复合碳纤维2800℃石墨化后,氧化石墨烯含量增加到2.0%时,复合石墨纤维的热导率达到435.57 W·m-1·K-1,结构更加致密。 相似文献
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Reddy AL Kumar A Currano LJ Churaman W Dubey M Ajayan PM 《Journal of nanoscience and nanotechnology》2011,11(2):1111-1116
Aligned CNT mats were prepared by thermal chemical vapor deposition (CVD) method by exposing a mixture of ferrocene and xylene vapor to the SiO2/Si substrates. Aligned CNT mats functionalized with reactive chemicals without disturbing CNT alignment were characterized by SEM, XRD, FT-IR, FT-Raman and XPS. The thermal stability of the CNT, CNT-OH and CNT-NaCIO4 are investigated using TG-DSC analysis. Oxidation and combustion temperatures of CNT mats were found to be decreased by functionalizing the CNT mats with NaClO4. 相似文献
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Tingkai Zhao Shasha Guo Xianglin Ji Yuxiang Zhao Xuan Wang Yuanbo Cheng 《Fullerenes, Nanotubes and Carbon Nanostructures》2017,25(6):391-396
In this article, three-dimensional (3D) heterostructured of MnO2/graphene/carbon nanotube (CNT) composites were synthesized by electrochemical deposition (ELD)-electrophoretic deposition (EPD) and subsequently chemical vapour deposition (CVD) methods. MnO2/graphene/CNT composites were directly used as binder-free electrodes to investigate the electrochemical performance. To design a novel electrode material with high specific area and excellent electrochemical property, the Ni foam was chosen as the substrate, which could provide a 3D skeleton extremely enhancing the specific surface area and limiting the huge volume change of the active materials. The experimental results indicated that the specific capacitance of MnO2/graphene/CNT composite was up to 377.1 F g?1 at the scan speed of 200 mV s?1 with a measured energy density of 75.4 Wh kg?1. The 3D hybrid structures also exhibited superior long cycling life with close to 90% specific capacitance retained after 500 cycles. 相似文献
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用CVD法制备碳纳米管,将碳纳米管超声分散在硫酸铜水溶液中,经过脱水、氢还原,制得碳纳米管-铜复合粉体。用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)对样品进行了表征。结果表明,碳纳米管在复合粉体中分散均匀,一些碳纳米管与纳米铜粒子结合在一起或被铜包覆。 相似文献
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Madhav Gautam Ahalapitiya H. Jayatissa 《Materials science & engineering. C, Materials for biological applications》2011,31(7):1405-1411
The gas sensing properties of graphene synthesized by a chemical vapor deposition (CVD) method are investigated. Synthesis of graphene is carried out on a copper substrate using a methane and hydrogen gas mixture by a CVD process at the atmospheric pressure. The graphene films are transferred to different substrates after wet etching of the copper substrates. The Raman spectra reveal that the graphene films made on SiO2/Si substrates are of high quality. The reflectance spectra of graphene were measured in UV/Visible region of the spectrum. Theoretically calculated reflectance spectra based on Fresnel's approach indicates that the CVD graphene has a single layer. The gas sensing properties of graphene were tested for different reducing gasses as a function of measurement temperature and gas concentration. It is found that the gas sensing characteristics such as response time, recovery time, and sensitivity depend on the target gas, gas concentration, test temperature, and the ambient gas composition. The cross sensitivity of few combinations of reducing gasses such as, NH3, CH4, and H2 was also investigated. 相似文献
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Myeong Jong Kim Dong Won Kim Jung Soo Yun Dae Hee Lee Yeon Jeong Oh Jeong A. Nam Sung Ryoung Kim Ji Hoon Lee Sung Young Park Byung-Gak Min Insik In 《Journal of Materials Science》2013,48(9):3357-3362
Stable dispersions of chemically reduced graphene oxide (RGO) were prepared by simple noncovalent interaction with poly(N-isopropyl acrylamide) (PNIPAAm)-grafted Pluronic (NGP). Prepared NGP/RGO assembly solutions showed temperature-dependent optical absorbance change below or above their lower critical solution temperature (LCST). Interestingly, LCSTs of NGP/RGO assemblies were unaffected compared with LCSTs of pristine NGPs regardless of the degree of PNIPAAm grafting in NGPs probably because noncovalent anchoring between PNIPAAm chains and RGO plates in NGP/RGO assembly is weak. This supports that PNIPAAm grafting on Pluronic occurred preferentially in hydrophilic PEO segments because hydrophobic PPO segments of NGP must be strongly anchoring on hydrophobic surface of RGO plates while PEO segments will be extended from RGO surface to aqueous medium. 相似文献
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Huaiping Rong Klaus-Hermann Dahmen Hamid Garmestani Muhuo Yu Karl I. Jacob 《Journal of Materials Science》2013,48(14):4834-4842
By engineering the fiber/matrix interface, the properties of the composite can be changed significantly. In this work, we increased the effective surface area of the fiber/matrix interface, to facilitate additional stress transfer between fibers and matrix, by grafting carbon nanotubes on to carbon fibers (in the form of carbon fabric) by two different methods: (1) chemical vapor deposition (CVD) method and (2) a purely chemical method. With the CVD process, carbon nanotubes (CNT) were directly grown on carbon fiber substrate using chemical vapors. For the chemical method, CNT with carboxyl groups were grafted on functionalized carbon fiber via a chemical reaction. The morphology of CNT/carbon fibers was examined by scanning electron microscope (SEM) which revealed uniform coverage of carbon fibers with CNT in both of CVD method and chemical grafting method. CNT-grafted woven carbon fibers were used to make carbon/epoxy composites, and their mechanical properties were measured using three-point bending and tension tests which showed that those with CNT-grafted carbon fiber reinforcements using the CVD process has 11 % higher tensile strength compared to those containing carbon fibers modified with the chemical method. Also, composites with CNT-grafted carbon fibers with chemical method showed 20 % higher tensile strength compared to composites with unmodified carbon fibers. The results of tensile test revealed that both CVD and chemical grafting could significantly improve the mechanical properties of the carbon fiber composites. 相似文献
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Wei Wang Isaac Ruiz Kazi Ahmed Hamed Hosseini Bay Aaron S. George Johnny Wang John Butler Mihrimah Ozkan Cengiz S. Ozkan 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(16):3389-3396
In this work, we report the synthesis of an three‐dimensional (3D) cone‐shape CNT clusters (CCC) via chemical vapor deposition (CVD) with subsequent inductively coupled plasma (ICP) treatment. An innovative silicon decorated cone‐shape CNT clusters (SCCC) is prepared by simply depositing amorphous silicon onto CCC via magnetron sputtering. The seamless connection between silicon decorated CNT cones and graphene facilitates the charge transfer in the system and suggests a binder‐free technique of preparing lithium ion battery (LIB) anodes. Lithium ion batteries based on this novel 3D SCCC architecture demonstrates high reversible capacity of 1954 mAh g?1 and excellent cycling stability (>1200 mAh g?1 capacity with ≈100% coulombic efficiency after 230 cycles). 相似文献
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Load transfer of the graphene/carbon nanotube (CNT)/polyethylene hybrid nanocomposite is studied here from molecular dynamics (MD) simulations. Simulations of this composite material under uniaxial tension were conducted by varying CNT’s position and diameter in the polymer matrix. The obtained results show that: (1) The peak strength of stress and strain evolution in the polymer matrix is lower than the peak strength of the graphene/graphene and graphene/polymer interfaces. Hence, the damage zone is always located in the polymer matrix. (2) Agglomerated two-layer graphenes do not possess an increased value in the peak strength compared with single-layer graphene-reinforced polymer nanocomposite (PNC), while two separate layers of graphene show slightly higher peak strength. (3) The largest peak strength is observed before CNT moves to the center of the polymer matrix. The damage location moves from the upper to the lower part of CNT when the CNT is located at the centre of polymer matrix. (4) The influence of the CNT diameter on the peak strength is not obvious, while the damage location and shape in the polymer matrix changes with respect to varying CNT diameters. In addition, the damage zone always falls outside the interphase zone. 相似文献
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Qiuhong Zhang Jianwei Liu Ryan Sager Liming Dai Jeffery Baur 《Composites Science and Technology》2009
Growing carbon nanotubes (CNT) on the surface of high performance carbon fibers (CF) provides a means to tailor the thermal, electrical and mechanical properties of the fiber–resin interface of a composite. However, many CNT growth processes require pretreatment of the fiber, deposition of an intermediate layer, or harsh growth conditions which can degrade tensile properties and limit the conduction between the fiber and the nanotubes. In this study, high density multi-wall carbon nanotubes were grown directly on two different polyacrylonitrile (PAN)-based carbon fibers (T650 and IM-7) using thermal Chemical Vapor Deposition (CVD). The influence of CVD growth conditions on the single-fiber tensile properties and CNT morphology was investigated. The mechanical properties of the resultant hybrid fibers were shown to depend on the carbon fiber used, the presence of a sizing (coating), the CNT growth temperature, growth time, and atmospheric conditions within the CVD chamber. The CNT density and alignment morphology was varied with growth temperature and precursor flow rate. Overall, it was concluded that a hybrid fiber with a well-adhered array of dense MWCNTs could be grown on the unsized T650 fiber with no significant degradation in tensile properties. 相似文献
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Hierarchically structured hybrid composites are ideal engineered materials to carry loads and stresses due to their high in-plane specific mechanical properties. Growing carbon nanotubes (CNTs) on the surface of high performance carbon fibres (CFs) provides a means to tailor the mechanical properties of the fibre–resin interface of a composite. The growth of CNT on CF was conducted via floating catalyst chemical vapor deposition (CVD). The mechanical properties of the resultant fibres, carbon nanotube (CNT) density and alignment morphology were shown to depend on the CNT growth temperature, growth time, carrier gas flow rate, catalyst amount, and atmospheric conditions within the CVD chamber. Carbon nanotube coated carbon fibre reinforced polypropylene (CNT-CF/PP) composites were fabricated and characterized. A combination of Halpin–Tsai equations, Voigt–Reuss model, rule of mixture and Krenchel approach were used in hierarchy to predict the mechanical properties of randomly oriented short fibre reinforced composite. A fractographic analysis was carried out in which the fibre orientation distribution has been analyzed on the composite fracture surfaces with Scanning Electron Microscope (SEM) and image processing software. Finally, the discrepancies between the predicted and experimental values are explained. 相似文献