碳纳米管/聚合物纳米复合材料研究进展

碳纳米管/聚合物纳米复合材料是近几年发展起来的一个新的研究方向。本文从增强和功能性两个方面评述了碳纳米管/聚合物纳米复合材料的发展过程以及最新进展，详细讨论了碳纳米管在聚合物中的分散、取向和胃面相互作用对复合材料力学性能的影响，介绍了碳纳米管的加入赋予聚合物的一些新的光电性能，并对今后的研究方向进行了展望。     

碳纳米管/聚合物复合材料加工过程中原位取向方法与技术

碳纳米管具有优异的力学、电学等性能,但是在聚合物复合材料中的无规状态不能发挥出其自身的优异性能.本文从碳纳米管/聚合物复合材料的加工过程实现取向增强入手,结合自己的研究成果,综述了在外力、电场、磁场、液晶诱导等作用下制备取向碳纳米管/聚合物复合材料.可以看出,经过精心设计的力场、电场、磁场和液晶作用可以使碳纳米管在聚合物复合材料加工过程中取向,并进而提高了力学和电学性能,但取向程度均有待提高.     

碳纳米管/聚合物基柔性电磁干扰屏蔽复合材料研究进展

当今,柔性可穿戴电子设备、航空航天等领域的快速发展对柔性、轻质电磁干扰(electromagnetic interference,EMI)屏蔽材料的需求不断增加,碳纳米管/聚合物基复合材料因具有柔性好、质量轻、导电性和机械稳定性优异、EMI屏蔽效能可调等优点而备受关注。本文介绍了电磁屏蔽机理,对碳纳米管的分散方法和碳纳米管/聚合物基柔性EMI屏蔽复合材料的制备方法进行了对比总结,综述了碳纳米管/聚合物基柔性EMI屏蔽复合材料的研究进展。最后,提出了碳纳米管/聚合物基柔性EMI屏蔽复合材料亟待解决的关键科学问题,并对其未来发展趋势进行了展望。     

基于碳纳米管的超级电容器研究进展

综述了基于碳纳米管及其复合材料作超级电容器的电极材料的研究现状,通过对碳纳米管的改性或与其它材料复合,能有效地提高电容器的电容特性。总结了近几年来在开发超级电容器电极材料领域中对碳纳米管的活化和提高碳纳米管的分散性技术、碳纳米管与过渡金属氧化物复合材料、碳纳米管与导电聚合物复合材料以及碳纳米管与石墨烯复合材料研究的进展。     

尼龙/碳纳米管复合材料研究进展

碳纳米管(CNTs)由于其独特的结构,较高的长径比,较大的比表面积,且具有超强的力学性能和良好的导热性,已经证明是塑料的非常优异的导电填料,聚合物基碳纳米管复合材料可望应用于材料领域的多个方面,尤其在汽车、飞机及其它飞行器的制造等军事和商业应用上带来革命性的突破。本文介绍了碳纳米管的结构形态和碳纳米管的制备、纯化、修饰方法及聚合物基碳纳米管复合材料的制备、性能,并综述了近几年来尼龙/碳纳米管复合材料的研究进展及应用前景。     

碳纳米管的修饰及其在超级电容器中的应用

碳纳米管以其窄孔径分布、高有效比表面积、良好导电性能、良好力学性能、优良化学稳定性和良好热稳定性以及较低成本等优点,被认为是超级电容器的理想电极材料之一.本文结合碳材料具有的双电层电容和金属氧化物、导电聚合物具有的准法拉第电容,综述了碳纳米管的修饰处理技术及碳纳米管/金属氧化物、碳纳米管/导电聚合物复合材料、碳纳米管原位再生长技术的研究进展,指出碳纳米管的修饰能更好地改善其电化学性质,因此碳纳米管复合材料是超级电容器电极材料研究的一个重要发展方向.     

聚苯乙烯/碳纳米管复合材料研究进展

聚苯乙烯/碳纳米管复合材料是近年来开发的新型聚合物基复合材料,具有独特的一维纳米管分散微结构,往往表现出比纯聚苯乙烯更好的机械力学性能、电学性能和热性能等,在诸多领域具有广泛的应用前景.本文首先简要介绍了碳纳米管的结构特点、制备与纯化和性能,然后重点阐述了聚苯乙烯/碳纳米管复合材料的几种制备方法、结构表征以及力学、电学和热性能等方面的研究进展,并对聚苯乙烯共聚物/碳纳米管复合材料的研究现状进行介绍.     

多壁碳纳米管对PS分子量影响的研究

由于碳纳米管（CNT）具有优异的力学、电学、光学等性能,近年来,聚合物／碳纳米管（polymer／CNT）复合材料的研究已经成为研究者关注的热点。相关的研究主要集中在：一是将CNT作为填充材料制各复合材料,使复合材料的力学、电学等性能得到提高。二是将CNT作为主体,用聚合物对CNT进行修饰,使CNT在有机溶剂中能够获得良好的溶解度。而对于在聚合反应中,CNT的加入对聚合物分子量影响的研究,相关的报道较少。本文利用悬浮聚合法制备了聚苯乙烯／多壁碳纳米管（PS／MWNT）复合材料,采用透射电镜（TEM）和凝胶渗透色谱（GPC）对其进行了分析,详细研究了MWNT对于PS分子量的影响。     

含氟聚合物修饰碳纳米管及其聚氨酯复合疏水膜的研究

利用羟基碳纳米管上的羟基与2-溴异丁基酰溴之间的简单反应, 在碳纳米管上引入了含溴ATRP引发剂, 并进一步引发含氟丙烯酸酯的ATRP聚合, 从而在碳纳米管表面接枝上了低表面能的含氟聚合物. 红外光谱(FT-IR)、热重分析(TGA)和透射电镜(TEM)的研究结果表明碳纳米管与含氟聚合物之间为化学键连接. 以此低表面能聚合物包裹的碳纳米管作为填充粒子, 采用溶液浇铸方法制备了聚氨酯/碳纳米管复合膜, 并利用溶剂四氢呋喃(THF)刻蚀表面获得了不同碳纳米管裸露程度的复合膜材料. 静态接触角测试结果表明, 无论是羟基碳纳米管还是低表面能修饰的碳纳米管均可提高其复合膜的疏水性能, 且其疏水性能随碳纳米管含量的增加而增加; 相同含量时, 含氟聚合物接枝后的碳纳米管使复合膜具有更佳的疏水性能, 膜表面经溶剂刻蚀后可显著提高其疏水性能. 采用扫描电子显微镜(SEM)研究了加入碳纳米管和溶剂刻蚀对聚合物表面微观结构以及材料表面疏水性能的影响. 上述结果表明: 利用接枝聚合物可改变碳纳米管本身的疏水性能, 并可进一步制备新型的具有表面疏水性能的聚合物纳米复合材料.     

欧洲聚合物联合会(EPF)第二届夏季大学“纳米结构聚合物材料”讲座

时间 :2 0 0 3年 5月 2 5～ 3 0日　地点 :意大利Ｇａｒｇｎａｎｏ(ＢＳ)讲题内容 :纳米结构材料综论 ;纳米材料模型化 ;超分子聚合物 ;控制有序纳米结构的聚合物络合物 ;树枝状大分子纳米材料 ;嵌段共聚物作为纳米材料 ;纳米结构热固性树脂 ;碳纳米管 聚合物纳米复合材料新性能 ;碳纳米管在聚合物中的应用 ;聚合物 层状硅酸盐纳米复合材料 ;纳米复合材料的流变行为 ;用溶胶 凝胶技术制备杂混化合物 ;多面体齐聚物硅倍半烷 (ＰＯＳＳ)杂化聚合物材料 ;柱状纳米材料与燃料电池 ;反应性加工制备杂化化合物 ;预成形纳米填料用于原位合成 ;生…     

Thermal properties enhancement of epoxy resins by incorporating polybenzimidazole nanofibers filled with graphene and carbon nanotubes as reinforcing material

Enhancement of thermal properties of epoxy resins was achieved by incorporation of polybenzimidazole (PBI) fibermats filled with carbon nanomaterials, prepared by the solution electrospinning technique. Different type of carbon nanostructures (carbon nanotubes, graphite flakes, graphene nanoplatelets and carbon black) were compared as fillers in polybenzimidazole fibers. The carbon-PBI-fibermats showed remarkable thermal transport properties and therefore, they were studied as thermal reinforcement material for epoxy composites. Mechanical and thermal properties of produced composites were evaluated and the effectiveness of different types of carbon fillers examined. Results showed that the produced carbon filled fibermats can be used effectively as a thermal reinforcing material in epoxy resins, offering several advantages.     

Reversible Amidation Chemistry Enables Closed-Loop Chemical Recycling of Carbon Fiber Reinforced Polymer Composites to Monomers and Fibers

Highly efficient recycling of carbon fiber reinforced polymer composites into monomers and fibers is a formidable challenge. Herein, we present a closed-loop recycling approach for carbon fiber reinforced polymer composites using reversible amidation chemistry, which enables the complete recovery of intact carbon fibers and pure monomers. The polymer network, synthesized by amidation between a macromonomer linear polyethyleneimine and a bifunctional maleic anhydride cross-linker, serves as a matrix for the construction of composites with exceptional mechanical properties, thermal stability and solvent resistance. The matrices can be fully depolymerized under the acidic condition at ambient temperature, allowing the effective separation and recovery of both carbon fibers and the two monomers. The reclaimed carbon fibers retain nearly identical mechanical properties to pristine ones, while pure monomers are recycled with high separation yields (>93 %). They can be reused in for multiple cycles for the manufacture of new composites, whose mechanical properties recover over 95 % of their original properties. This line of research presents a promising approach for the design of high-performance and sustainable thermoset composites, offering significant environmental and economic benefits.     

ELECTRICAL RESISTIVITY,CRYSTALLIZATION AND MECHANICAL PROPERTIES OF POLYPROPYLENE/MULTI-WALLED CARBON NANOTUBE/CALCIUM CARBONATE COMPOSITES PREPARED BY MELT MIXING

Polypropylene(PP)/multi-walled carbon nanotube(MWCNT)/calcium carbonate(CaCO_3)composites are prepared by melt mixing using two types of CaCO_3 of different sizes.The electrical resistivities of the composites with the two types of CaCO_3 are all lower than those of the corresponding PP/MWCNT composites at various MWCNT loadings (1 wt%-5 wt%).The morphology of the composites is investigated by field emission scanning electron microscopy (FESEM).The crystallization behavior of PP in the composites is char...     

Enhancement of water barrier properties and tribological performance of hybrid glass fiber/epoxy composites with inclusions of carbon and silica nanoparticles

Water barrier properties and tribological performance (hardness and wear behavior) of new hybrid nanocomposites under dry and wet conditions were investigated. The new fabricated hybrid nanocomposite laminates consist of epoxy reinforced with woven and nonwoven tissue glass fibers and two different types of nanoparticles, silica (SiO₂) and carbon black nanoparticles (C). These nanoparticles were incorporated into epoxy resin as a single nanoparticle (either SiO₂ or C) or combining SiO₂ and C nanoparticles simultaneously with different weight fractions. The results showed that addition of carbon nanoparticles with 0.5 and 1 wt% resulted in maximum reduction in water uptake by 28.55% and 21.66%, respectively, as compared with neat glass fiber reinforced epoxy composites. Addition of all studied types and contents of nanoparticles improves hardness in dry and wet conditions over unfilled fiber composites. Under dry conditions, maximum reduction of 47.26% in weight loss was obtained with specimens containing 1 wt% carbon nanoparticles; however, in wet conditions, weight loss was reduced by 17.525% for specimens containing 0.5 wt% carbon nanoparticles as compared with unfilled fiber composites. Diffusion coefficients for different types of the hybrid nanocomposites were computed using Fickian and Langmuir models of diffusion. Copyright © 2017 John Wiley & Sons, Ltd.     

二氧化碳膨胀乙醇体系中碳基金属复合物的合成及其催化和电化学性能(英文)

与块体材料相比,功能复合材料表现了更加优异的性能,而且比其中任何单一组分的性能都好,因此在催化、锂离子电池等领域得以广泛研究.通常情况下,在复合材料的制备中金属或金属氧化物粒子要求能够以足够小的粒径在基底上均匀分散,并实现活性组分负载量的可控.据报道,很多方法可以将金属(或氧化物)活性组分引入到载体之中,比如水热/溶剂热、水解、热分解、化学气相沉积等,但这些方法均存在如下缺点.第一,为了获得满意的负载量和可控包覆,碳基底需要预氧化处理使其表面含有丰富的含氧官能团.例如,由于碳纳米管自身的相容性和加工性较差,需要硝酸预氧化处理;石墨烯也需要预处理为石墨烯氧化物然后再进行第二组分的负载.但是,剧烈的氧化处理条件不可避免地造成对碳sp~2结构和电子特性的破坏,并且增加了繁杂的后续处理过程.第二,金属组分前驱体在基底上负载不完全,易形成自由粒子聚集在溶液中,从而降低活性组分的有效利用.第三,传统方法中由于使用水、乙醇等表面张力大的极性溶剂,导致粒子结晶再生长,形成的颗粒尺寸大,对催化剂会降低活性表面积及催化效率;对于电池材料会增加电极/电解液的接触面积,增加锂离子的扩散距离及电池充电过程的内部应力.而且,有机溶剂由于粘度大,不利于金属纳米粒子在基底上的均匀分散及合成过程的绿色化.因此,我们利用资源丰富,廉价的二氧化碳作为绿色溶剂,研究了二氧化碳膨胀的乙醇体系中金属(氧化物)纳米粒子在碳基底上均匀负载的方法.由于超临界二氧化碳具有独特的低粘度、"零"表面张力、高扩散能力、以及物性参数随温度和压力可调等特点,可以使金属(氧化物)前驱体不受液体毛细作用的限制在孔道中快速、均一地分散,保证孔结构稳定,对多孔复合材料的加工和制备表现了巨大的优势.同时,超临界二氧化碳的抗溶剂能力也能够有效降低乙醇和水引起的溶剂效应,从而降低纳米粒子之间的聚集.此外,通过改变前驱体的浓度可以精确调控表面组分的负载量.更重要的是,碳基底可以直接利用制备碳基复合材料,无需任何预处理及表面活性剂参与,避免了前处理对基底的形貌和电子特性的破坏.本综述首先介绍了超临界二氧化碳膨胀乙醇体系的属性,讨论了碳基复合材料在该体系中的形成机理.然后分别介绍了零维碳球、一维碳纳米管、二维石墨烯、三维多孔碳材料作为基底形成的一系列金属(氧化物)复合材料,及这些材料在催化和锂离子电池领域中的应用.最后,对超临界二氧化碳沉积方法的应用进行了总结和展望.     

Effect of pyrolytic carbon content on microstructure and tribological properties of C/C-SiC brake composites fabricated by isothermal chemical vapor infiltration

Four types of C/C-SiC composites were prepared by isothermal chemical vapor infiltration (ICVI) of SiC on C/C preforms of different densities. Tribological properties of the composites were evaluated by using MM-1000 testing machine. The results indicated that the friction behaviors of the composites are a strong function of the content of pyrolytic carbon (in matrix). Moreover, friction film was formed on the surface and increased with pyrolytic carbon content. Debris originated of particulate and film-type have been observed after friction testing with ratio and size determined by the content of pyrolytic carbon.     

Flexural properties of fiber‐reinforced polypropylene composites with and without a transcrystalline layer

The flexural properties of isotactic polypropylene (PP) matrix composites reinforced with 5–30 vol% of unidirectional pitch‐based carbon, polyacrylonitrile (PAN)‐based carbon, e‐glass or aramid fibers were measured using both static and dynamic test methods. Previous research has shown that these pitch‐based carbon and aramid fibers are capable of densely nucleating PP crystals at the fiber surface, leading to the growth of an oriented interphase termed a “transcrystalline layer” (TCL), while the e‐glass and PAN‐based carbon fibers show no nucleating ability. The PP matrices examined included unmodified homopolymers, nucleated homopolymers and PP grafted with maleic anhydride (MA). The composites based on the unmodified PP homopolymers all exhibited poor fiber/matrix adhesion, regardless of fiber type and presence or absence of a TCL. The addition of nucleating agent to the PP matrix had no measurable effect on either the amount of TCL material in pitch‐based carbon‐fiber‐reinforced composites, as measured by wide‐angle X‐ray scattering, WAXS, or the static flexural properties of the composites reinforced with either type of carbon fiber. However, MA grafting reduced the transcrystalline fraction of the matrix in pitch‐based carbon‐fiber‐reinforced composites; at the highest level of MA grafting, the TCL was completely suppressed. In addition, high levels of MA grafting improved the transverse flexural modulus of the composites containing both types of carbon fibers, and reduced the extent of fiber pull‐out, indicating an improvement in fiber/matrix adhesion. Copyright © 1999 John Wiley & Sons, Ltd.     

Stress wave attenuation in composites during ballistic impact

Experimental studies are presented on stress wave attenuation during ballistic impact for four types of polymer matrix composites. The materials considered are plain weave E-glass/epoxy, 8H satin weave T300 carbon/epoxy and two types of hybrid composite made using plain weave E-glass fabric and 8H satin weave T300 carbon fabric with epoxy resin. Strain profiles were obtained during ballistic impact event at certain distances from the point of impact. There is stress wave attenuation leading to reduction in peak strains obtained as the stress wave propagates away from the point of impact. Further, it is observed that ballistic limit velocity, V₅₀, can be increased compared to carbon only composites by adding E-glass layers to T300 carbon layers.     

Effect of carbon nanofibers on mechanical and electrical behaviors of acrylonitrile‐butadiene rubber composites

Recently, carbon nanofibers have become an innovative reinforcing filler that has drawn increased attention from researchers. In this work, the reinforcement of acrylonitrile butadiene rubber (NBR) with carbon nanofibers (CNFs) was studied to determine the potential of carbon nanofibers as reinforcing filler in rubber technology. Furthermore, the performance of NBR compounds filled with carbon nanofibers was compared with the composites containing carbon black characterized by spherical particle type. Filler dispersion in elastomer matrix plays an essential role in polymer reinforcement, so we also analyzed the influence of dispersing agents on the performance of NBR composites. We applied several types of dispersing agents: anionic, cationic, nonionic, and ionic liquids. The fillers were characterized by dibutylphtalate absorption analysis, aggregate size, and rheological properties of filler suspensions. The vulcanization kinetics of rubber compounds, crosslink density, mechanical properties, hysteresis, and conductive properties of vulcanizates were also investigated. Moreover, scanning electron microscopy images were used to determine the filler dispersion in the elastomer matrix. The incorporation of the carbon nanofibers has a superior influence on the tensile strength of NBR compared with the samples containing carbon black. It was observed that addition of studied dispersing agents affected the performance of NBR/CNF and NBR/carbon black materials. Especially, the application of nonylphenyl poly(ethylene glycol) ether and 1‐butyl‐3‐methylimidazolium tetrafluoroborate contributed to enhanced mechanical properties and electrical conductivity of NBR/CNF composites.     

Rapeseed oil as main component in synthesis of bio-polyurethane-polyisocyanurate porous materials modified with carbon fibers

Porous polyurethane-polyisocyanurate (PUR-PIR) composites have been synthesized using two types of rapeseed oil-based bio-polyols. The bio-polyols from rapeseed oil were synthesized using two methods: (i) transesterification and (ii) epoxidation followed by oxirane ring opening. The PUR-PIR porous materials were prepared with two isocyanate indices, 150 and 250, and were modified with carbon fibres (CF) in an amount of 3 and 6 wt% of the total foam mass. The structure of the composites was examined using scanning electron microscopy. Thermal and mechanical properties of the composites were determined through a thermogravimetric analysis and measurements of the thermal conductivity, compressive strength, and Young modulus. The influence of CF on the composite flammability was analyzed using oxygen index and cone calorimeter tests. The investigations of the mechanical properties have shown that the compressive strength is the most beneficial in the case of the PUR-PIR foams modified with 6 wt % of CF. The studies have shown that the oxygen index of the composites increases with an increasing CF content and isocyanate index. An addition of CF reduces the heat rate release, especially for the materials with an isocyanate index of 250. An introduction of CF into the PUR-PIR foam structure is a way to improve the thermal stability and to decrease the flammability of final porous composites.