纳米碳管在聚合物中的应用及其复合材料研究进展

介绍了纳米碳管的制备、表面改性等，论述了纳米碳管在聚合物中的应用及其复合材料的制备方法和研究进展，并总结了存在的主要问题，展望了纳米碳管／聚合物基复合材料的应用前景。     

纳米碳管/环氧树脂纳米复合材料的研究

采用熔融混合法合成了不同纳米碳管含量的纳米碳管/环氧树脂复合材料,测试了弯曲性能、冲击强度,并利用扫描电镜(TEM)对产物进行了表征,同时,针对纳米碳管对环氧树脂电学性能的影响做了初步研究。结果表明,当纳米碳管含量为0.05%时,纳米碳管/环氧树脂复合材料的冲击强度、弯曲强度最高,弯曲强度提高100%,弯曲模量提高41%,冲击强度提高4倍,纳米碳管在环氧树脂基体中呈单根分散,纳米碳管使环氧树脂的体积电阻下降,导电性增加。     

纳米碳管／聚酰亚胺复合材料制备与性能研究

利用纳米碳管的N甲基吡咯烷酮分散液，通过改变纳米碳管表面的性质和薄膜的制备条件，成功地制备了一系列均匀的纳米碳管，聚酰亚胺薄膜。研究结果表明，添加酰氯化后的纳米碳管到聚酰亚胺中可以改善聚酰亚胺的拉伸性能，而对聚酰亚胺的热稳定性和光学性质没有明显的影响。当添加1．0％的纳米碳管时，与纯PI相比复合材料的弹性模量增加了25．6％，拉伸强度增加了31．0％，断裂伸长率增加了7．6％。     

纳米碳管/环氧树脂复合材料的制备及力学性能

报道了利用催化裂解法制备的纳米碳管合成环氧树脂复合材料的技术及工艺条件。利用透射电子显微镜(TEM)对制备的复合材料进行观察表征;通过拉伸及压缩实验对纳米碳管/环氧树脂复合材料的力学性能进行了测试。实验结果表明:纳米碳管的加入可以明显地改变环氧树脂基体材料的力学性能。      

单壁纳米碳管/纳米铝基复合材料的增强效果

用半连续氢电弧法和活性氢等离子蒸发法分别制备出单壁纳米碳管(SWNTs)和纳米A1粉体，然后用提纯后的SWNTs和纳米A1粉体制备出SWNTs含量(质量分数)分别为0、2．5％、5．0％、7．5％和10.0％的单壁纳米碳管／纳米铝基块体复合材料．SWNTs对高强度纳米A1基体具有显著的增强作用，当SWNTs含量小于5．0％时，材料的硬度随着SWNTs含量的提高线性上升．其中5％SWNTs和纳米A1的复合增强效果最好，其硬度可达2.89GPa，大约是粗晶A1(0．15GPa)的20倍．当SWNTs含量超过5．0％时，增强效果开始缓慢的下降．讨论了单壁纳米碳管增强纳米铝基复合材料的强化机制．     

纳米碳管增强炭/炭复合材料的研究进展

纳米碳管(CNTs)具有独特的结构、优异的力学性能、热稳定性与传导性能,是炭/炭(C/C)复合材料理想的增强体.综述了纳米碳管增强炭/炭(CNTs/C/C)复合材料的制备方法,讨论了该复合材料的微观结构、摩擦学性能和传导性能,并展望了CNTs/C/C复合材料的潜在应用和发展趋势.     

聚合物/粘土纳米复合材料研究进展

聚合物/粘土纳米复合材料(PCN)是近几年纳米材料领域中的研究热点.综述了聚合物/粘土纳米复合材料的几种制备方法及研究进展,并将纳米复合材料与普通材料的物理性能相比较,得知纳米复合材料有优良的物理性能.总结了这一领域尚待解决的问题.     

纳米碳管/羟基磷灰石复合材料的凝胶注模

采用凝胶浇注成型工艺制备了纳米碳管/ 羟基磷灰石复合材料坯体。研究了p H 值、分散剂、固相含量(纳米碳管和羟基磷灰石在料浆中的质量分数) 、分散工艺等因素对料浆和复合材料坯体性能的影响, 对坯体的力学性能进行了测试, 借助扫描电镜分析了坯体的微观组织。实验发现, 料浆的p H 值应控制在10～12 的范围内;聚甲基丙烯酸铵的浓度为0. 6 %时, 羟基磷灰石悬浮体流动性最好; 十二烷基磺酸钠的浓度在SDS/ CNTs = 1 %～2 %时, 纳米碳管/ 羟基磷灰石复相料浆的粘度最低; 采用球磨法制备的复相料浆固相含量达到55 % , 复合材料坯体的抗弯强度达到57. 403 MPa 。      

功能性聚合物基纳米复合材料

对聚合物基纳米复合材料研究现状进行了概述，并就其在电、磁、发光性能以及光催化等方面的国内外研究进展进行了全面综述。     

聚合物/无机纳米复合材料研究进展

本文对无机纳米材料的结构特征及预处理技术 ,对用于制备聚合物 /无机纳米复合材料的直接分散法、插层复合法、溶胶 -凝胶 (sol-gel)法等 3种方法及聚合物 /无机纳米复合材料的性能进行了综述。并对本领域今后的发展趋势提出了一些看法。     

Electrospinning carbon nanotube polymer composite nanofibers

The unique and exceptional physical properties of carbon nanotubes have inspired their use as a filler within a polymeric matrix to produce carbon nanotube polymer composites with enhanced mechanical, thermal and electrical properties. A powerful method of synthesising nanofibers comprising these polymer composites is electrospinning, which utilises an applied electric stress to draw out a thin nanometer-dimension fiber from the tip of a sharp conical meniscus. The focussing of the flow due to converging streamlines at the cone vertex then ensures alignment of the carbon nanotubes along the fiber axis, thus enabling the anisotropic properties of the nanotubes to be exploited. We consider the work that has been carried out to date on various aspects encompassing preprocessing, synthesis and characterisation of these electrospun polymer composite nanofibers as well as the governing mechanisms and associated properties of such fibers. Particular attention is also dedicated to the theoretical modelling of these fiber systems, in particular to the electrohydrodynamic modelling of electrospinning polymer jets.     

Preparation of continuous carbon nanotube networks in carbon fiber/epoxy composite

In order to optimize carbon nanotube (CNT) dispersion state in fiber/epoxy composite, a novel kind of CNT organization form of continuous networks was designed. The present work mainly discussed the feasibility of preparing continuous CNT networks in composite: Fiber fabric was immersed into CNT aqueous solution (containing dispersant) followed by freeze drying and pyrolysis process, prior to epoxy infusion. The morphologies of fabric with CNTs were observed by Scanning Electron Microscope. The relationship between CNT networks and flowing epoxy resin was studied. Properties of composite, including out-of-plane electrical conductivity and interlaminar shear strength (ILSS), were measured. The results demonstrated that continuous and porous CNT networks formed by entangled CNTs could be assembled in fiber fabric. Most part of them were preserved in composite due to the robustness of network structures. The preserved CNT networks significantly improved out-of-plane electrical conductivity, and also have an effect on ILSS value.     

Conductivity in carbon nanotube polymer composites: A comparison between model and experiment

Carbon nanotubes (CNTs) demonstrate remarkable conductive behaviour, which suggests promising applications. Their outstanding properties have been used in the development of CNT–polymer composites as possible alternative materials for various applications, such as flexible electrodes, antistatic coatings and piezoresistive sensors. In our study we focused our attention on the evaluation and modelling of CNT-filled epoxy resin electrical conductivity. We discuss the results with regard to the influence of CNTs dimensions and content. Exploiting the Dijkstra algorithm, we implemented a simulation code which determines the shortest route between electrodes in the polymer. The longer the path inside the polymer, the more non-conductive the composite becomes, since polymer resistivity is orders of magnitude higher than that of CNTs. We compared these simulated results with experimental data obtained at several wt% and found a good correspondence between modelling and experimental results.     

Carbon nanotube reinforced polymer composites—A state of the art

Because of their high mechanical strength, carbon nanotubes (CNTs) are being considered as nanoscale fibres to enhance the performance of polymer composite materials. Novel CNT-based composites have been fabricated using different methods, expecting that the resulting composites would possess enhanced or completely new set of physical properties due to the addition of CNTs. However, the physics of interactions between CNT and its surrounding matrix material in such nano-composites has yet to be elucidated and methods for determining the parameters controlling interfacial characteristics such as interfacial shear stress, is still challenging. An improvement of the physical properties of polymer nanocomposites, based on carbon nanotubes (CNTs), is addicted to a good dispersion and strong interactions between the matrix and the filler.     

Increasing the Tensile Property of Unidirectional Carbon/Carbon Composites by Grafting Carbon Nanotubes onto Carbon Fibers by Electrophoretic Deposition

Although in-situ growing carbon nanotubes(CNTs) on carbon fibers could greatly increase the matrix-dominated mechanical properties of carbon/carbon composites(C/Cs),it always decreased the tensile strength of carbon fibers.In this work,CNTs were introduced into unidirectional carbon fiber(CF) preforms by electrophoretic deposition(EPD) and they were used to reinforce C/Cs.Effects of the content of CNTs introduced by EPD on tensile property of unidirectional C/Cs were investigated.Results demonstrated that EPD could be used as a simple and efficient method to fabricate carbon nanotube reinforced C/Cs(CNT—C/Cs) with excellent tensile strength,which pays a meaningful way to maximize the global performance of CNT—C/Cs.     

Dielectric polymer matrix composite films of CNT coated with anatase TiO2

This study presents the fabrication method and the dielectric property of polymer matrix composite films of carbon nanotube (CNT) coated with TiO₂. The TiO₂ was coated with sol-gel method using titanium (IV) butoxide (TNBT), HO₂ and benzyl-alcohol as the surfactant. The configuration of CNT-TiO₂ hybrid was observed with the field emission scanning electron microscope images. The coated TiO₂ was thermally treated and transformed into the anatase structure to enhance the mechanical strength and get the high insulating property. The anatase structure was proved from the diffraction angles of XRD. The CNT-TiO₂ hybrid was mixed with the epoxy resin using 3-roll-mil and casted into the films using film casting method. The structure of CNT-TiO₂ hybrid was ascertained to be maintained against the high shear stress during the mixing and casting processes. The dielectric property of the composite films was measured following IPC-TM-6550. The dielectric property at 1 GHz of the composite film of 5 wt.% CNT is about 10 and the loss tangent at 1 GHz is about 0.06.     

低温聚苯胺/碳纳米管复合材料的制备

采用原位聚合法合成出了具有较高导电性的聚苯胺及聚苯胺 /碳纳米管复合材料 ,考察了不同碳纳米管添加量对聚苯胺 /碳纳米管复合材料表面形态、材料结构及导电性的影响并进行了表征。结果证实 ,制备出的复合聚苯胺的电导率比所见报道值提高了 1～ 2个数量级 ,为高电导率聚苯胺的合成开辟了更广阔的前景。     

Multiwalled carbon nanotube reinforced polymer composites

Due to their high stiffness and strength, as well as their electrical conductivity, carbon nanotubes are under intense investigation as fillers in polymer matrix composites. The nature of the carbon nanotube/polymer bonding and the curvature of the carbon nanotubes within the polymer have arisen as particular factors in the efficacy of the carbon nanotubes to actually provide any enhanced stiffness or strength to the composite. Here the effects of carbon nanotube curvature and interface interaction with the matrix on the composite stiffness are investigated using micromechanical analysis. In particular, the effects of poor bonding and thus poor shear lag load transfer to the carbon nanotubes are studied. In the case of poor bonding, carbon nanotubes waviness is shown to enhance the composite stiffness.     

Mechanical Reinforcement of Polymers Using Carbon Nanotubes

Owing to their unique mechanical properties, carbon nanotubes are considered to be ideal candidates for polymer reinforcement. However, a large amount of work must be done in order to realize their full potential. Effective processing of nanotubes and polymers to fabricate new ultra‐strong composite materials is still a great challenge. This Review explores the progress that has already been made in the area of mechanical reinforcement of polymers using carbon nanotubes. First, the mechanical properties of carbon nanotubes and the system requirements to maximize reinforcement are discussed. Then, main methods described in the literature to produce and process polymer–nanotube composites are considered and analyzed. After that, mechanical properties of various nanotube–polymer composites prepared by different techniques are critically analyzed and compared. Finally, remaining problems, the achievements so far, and the research that needs to be done in the future are discussed.     

Preparation of carbon nanotube/chitosan/gold nanoparticle composite microspheres

The electrostatic layer-by-layer (LbL) assembly of acid-modified multi-walled carbon nanotubes (MWNTs) and biopolymer chitosan (CHIT) is realized on planar substrates and polystyrene (PS) microsphere templates, respectively. The successful stepwise growing process of the composite films on planar substrates is investigated and confirmed by scanning electron microscopy and UV-vis spectroscopy. The transfer of the LbL assembly of MWNTs and CHIT to spherical PS microspheres leads to novel (MWNT/CHIT)PS core-shell structure, on which the gold nanoparticles (GNPs) are deposited to fabricate GNP(MWNT/CHIT)PS composite microspheres. The glass carbon electrodes modified with such (MWNT/CHIT)PS or GNP(MWNT/CHIT)PS composites exhibit satisfactory electrocatalytic activities for biomolecule dopamine.