多壁碳纳米管复合材料的应用

多壁碳纳米管是一种具有很高的强度、高长径比、质量轻便等一些有益性能的一维纳米材料。从最近几年,多壁碳纳米管及一些纳米管的材料的深入研究来看,它的广阔的应用前景在不断的展现出来。根据一些聚合物为载体,通过对多碳纳米管表面的修饰,制备了多种不同功能的多碳纳米管的复合材料,来支撑未来复合材料领域的发展。     

高性能羧基化多壁碳纳米管/NR复合材料的制备、结构与性能

以超声分散的羧基化多壁碳纳米管(MC)悬浮液填充天然胶乳,采用喷雾干燥法制备MC/NR复合材料,研究偶联剂Si69和KH-550改性对复合材料中填料分散及各项性能的影响.结果表明:喷雾干燥法制备的MC/NR复合材料中碳纳米管分散较好;偶联剂Si69和KH-550与MC表面的羧基发生了化学反应,使其在复合材料中的分散得到进一步改善;当MC用量高于10份时,KH-550改性MC/NR复合材料表现出优异的物理性能和导电性能.     

多壁碳纳米管在国产碳纤维增强环氧树脂复合材料中应用

研究了一种简易有效的多壁碳纳米管(MWNTs)分散入环氧树脂的方法,对树脂的工艺性进行试验研究;使用碳纤维复丝的力学性能来表征纤维/树脂界面性能和纤维强度转化效果,制备了含MWNTs的环氧树脂/碳纤维预浸料,并对使用此预浸料制备的复合材料单向板进行力学性能测试。结果表明,当MWNTs的用量为E–51的0.5%时,二者混合球磨8 h后配制的树脂溶液适用期大于24 h,黏度小于0.8 Pa·s,树脂浇铸体拉伸强度78 MPa,弯曲强度106 MPa,断裂伸长率4.3%;添加MWNTs之后纤维/树脂结合良好,复合材料单向板拉伸强度提升了7.2%,弯曲强度提升了9.73%,压缩强度提升了6.82%,层剪强度提升了11.54%。     

环氧树脂/石墨烯/多壁碳纳米管复合材料力学性能研究

以环氧树脂(EP)为基体、石墨烯(GNP)和多壁碳纳米管(MWCNT)为增强材料制备了EP/GNP/MWCNT纳米复合材料,通过拉伸试验考察了GNP与MWCNT的混合比例对复合材料力学性能的影响。结果表明:当GNP与MWCNT的总添加量为0.3%、混合比例为50:50时,EP/GNP/MWCNT纳米复合材料的综合力学性能达到最佳,此时复合材料的弹性模量、拉伸屈服强度、拉伸断裂强度、破坏应变等均达到或接近最大值。     

多壁碳纳米管/聚苯硫醚管复合材料的电磁性能

采用熔融共混法制备了多壁碳纳米管/聚苯硫醚复合材料,研究了在0.5~18 GHz频段,不同碳纳米管含量对复合材料电磁性能的影响。结果表明,介电常数实部与虚部随着碳纳米管含量的增加而增大, 介电常数实部在测量范围内随频率的增加而减小, 具有明显的频响特性;复合材料的磁导率随多壁碳纳米管含量的增加变化不明显, 呈弱磁性;通过对复合材料反射衰减的计算发现,当吸收层匹配厚度为2 mm 时,复合材料在0.5~18 GHz频段具有较好的微波吸收性能;当碳纳米管含量为7 %（质量分数,下同）时,反射衰减最大达- 31.5 dB ,反射衰减小于- 10 dB的频宽为2.2 GHz。     

多壁碳纳米管/炭黑/顺丁橡胶导电复合材料的研究

采用机械共混法制备多壁碳纳米管(MWNTs)/炭黑/顺丁橡胶(BR)复合材料,研究其导电性和物理性能。结果表明,与炭黑相比,MWNTs能够更好地改善BR的电性能;当炭黑用量为40份时,加入1份MWNTs可使复合材料的体积电阻率从1.2×1010Ω.cm降至7.0×105Ω.cm;当MWNTs/炭黑用量比为5/40时,MWNTs和炭黑在BR中的协同补强作用较明显,复合材料的邵尔A型硬度、拉伸强度、拉断伸长率和撕裂强度均显著提高。     

羟基化多壁碳纳米管吸附硼的研究

以羟基化多壁碳纳米管(CNTs-OH)吸附分离水溶液的硼,用FTIR、SEM、TEM、XPS对吸附前后羟基化多壁碳纳米管进行测试表征,并考察了初始硼浓度、pH、吸附时间、吸附剂投加量、温度等条件对吸附的影响。结果表明,温度升高有利于吸附,但吸附剂投加量并不会使硼吸附量增加,溶液硼浓度1 000 mg/L、pH 10、吸附30 min时吸附效果较好。CNTs-OH与溶液中硼的吸附作用符合Freundlich模型,理论吸附量可达206.61 mg/g。羟基化多壁碳纳米管具有分离硼的潜在应用价值。     

聚苯乙烯/多壁碳纳米管复合材料的阻燃性能

综述了近年来聚苯乙烯/多壁碳纳米管复合材料的阻燃研究进展,详细介绍了其热解性能（包括热解温度和玻璃化转变温度）以及燃烧性能（包括热释放速率、质量损失速率和成炭性）,并对相关机理进行了深入的探讨,分析了多壁碳纳米管含量、长径比、杂质及表面改性处理对相应复合材料的热稳定性及阻燃性能的影响。     

Functionalized multi‐wall carbon nanotubes/silicone rubber composite as capacitive humidity sensor

Functionalized multi‐wall carbon nanotubes (MWCNTs) treated by mixed acids have been used to develop a capacitive humidity sensor based on MWCNTs/silicone rubber (SR) composite film. The MWCNTs/SR composites were prepared through conventional solution processed method. The micrographs of MWCNTs/SR composites were observed by transmission electron microscopy (TEM) and scanning electron microscope. The FT‐IR spectra demonstrated the successfully grafting of ? OH groups on the treated MWCNTs. The sensing properties of the composite at different relative humidity (RH) and frequency were characterized and linear sensing responses of the MWCNTs/SR composites to RH were observed. The treated MWCNTs/SR composite film (Tr‐film) had higher sensitivity than that of the untreated MWCNTs/SR composite film (Un‐film). Experimental data indicate that the Tr‐film exhibits an excellent long‐term stability, small hysteresis, and fine reproducibility. The response and recovery time of the Tr‐film were 30 and 27 s, respectively. Thereby, such Tr‐film had potential applications as humidity sensors. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40342.     

Resistive viscoelasticity of silicone rubber/carbon black composite

Electrical conductive polymer composites are shown as prospective flexible pressure and stretch sensors for detecting the dangerous deformations and for sensing the pressure with minimal intrusion. To better understand the piezoresistive mechanism and improve the performance of this type of sensor, a series of experiments were conducted to investigate the resistive viscoelasticity of silicone rubber/carbon black composite film. First, the flexible conductive composite film was composed with liquid silicone rubber as the matrix and conductive carbon black as the filler. The filler loading was fixed at 5 phr in mass ratio. Then, the resistive viscoelasticity of the composite film was studied as a function of frequency in the range from DC to 1 MHz, including resistive creep, resistive relaxation, and resistive recovery, although in a standard experiment, one‐step stress or one‐step strain was loaded in transient time and the resistance responses were measured. Result from the experiment shows that the creep of resistance is composed of two distinct segments. One is coincident with the strain creep of a typical viscoelastic material, while the other is quite different. Both the relaxation and the recovery of resistance exhibit strong frequency dependence. The relaxation speed becomes slower with the increase of exciting frequency except DC, and the relaxation speed is marginal when excited by DC electrical field. The recovery time becomes shorter with the increase of the exciting frequency. POLYM. COMPOS., 32:29–35, 2011. © 2010 Society of Plastics Engineers     

自组装型改性碳纳米管/NR复合材料的制备及性能研究

采用静电自组装技术结合乳液共混法制备改性多壁碳纳米管(MWNTs)/NR复合材料,并对复合材料的相态结构和性能进行研究。结果表明,经过混酸改性的MWNTs在NR基体中分散均匀;与NR和未改性MWNTs/NR复合材料相比,自组装型改性MWNTs/NR复合材料的热稳定性和物理性能明显提高。     

Microwave absorption performance of nitrile butadiene rubber/ethylene propylene diene monomer rubber filled with multiwalled carbon nanotubes

In recent times, there is an increasing need for effective control of electromagnetic pollution, which can avoid excessive radiation effects on the human body. Microwave absorption materials are attracting wide research interests to reduce electromagnetic pollution due to the rapid development of electronic equipment. In this study, Nitrile butadiene rubber (NBR)/ethylene propylene diene monomer rubber (EPDM) were mixed with multiwalled carbon nanotubes (MWCNT) to prepare microwave absorbing materials. The distribution of fillers, AC conductivity, complex permittivity, and microwave absorption performance of the composites were systematically investigated. It found that the AC conductivity, both real and imaginary parts of the permittivity were significantly improved in the composite with the increasing ratio of MWCNT contents. The NBR/EPDM/MWCNT composites with eight parts per hundred concerning with rubber (phr) MWCNT had a minimum reflection loss (RLmin) of −48.1 dB at the optimum thickness of 2.07 mm. Importantly, the adding sequence of MWCNT and plasticizer dioctyl phthalate (DOP) to the rubber matrix is found to play an important role in determining the distribution of fillers and the structure of polymer blends. The composite with plasticizer added before MWCNT exhibited a better impedance matching and as a result, achieved a good microwave absorption performance.     

Preparation of carbon nanotubes/hydrogenated nitrile rubber composite by ultrasonic technique

将低相对分子质量的液体氢化丁腈橡胶(HNBR)溶于丙酮溶剂中,加入碳纳米管,用超声波技术制备了液体HNBR与碳纳米管的复合母料,然后再与HNBR混炼、硫化,获得碳纳米管/HNBR复合材料.结果表明,碳纳米管在HNBR中分散性好,对HNBR有较好的增强性,但在后期机械加工中产生了断裂.     

Tribological behaviors of hybrid PTFE/nomex fabric/phenolic composite reinforced with multiwalled carbon nanotubes

Modification of composites was a general method to improve their tribological behaviors. On the way to explore composites with enhanced tribological behaviors, we have successfully prepared hybrid PTFE/Nomex fabric/phenolic composite filled with multiwalled carbon nanotubes (MWCNTs) or MWCNTs modified by polystyrene (PS) with a grafting to method. The results of pin‐on‐disc type wear tests indicated tribological behaviors were improved both for hybrid PTFE/Nomex fabric/phenolic composite filled with MWCNTs and MWCNTs‐PS, especially for that of filled with MWCNTs‐PS. And the probable reason was also discussed based on the characterization results. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Deformation processes of ultrahigh porous multiwalled carbon nanotubes/polycarbonate composite fibers prepared by electrospinning

Mechanical deformation processes of electrospun composite fibers based on polycarbonate with multiwalled carbon nanotubes (MWCNTs) were investigated by in situ tensile tests under transmission electron microscope (TEM) depending on morphology. Using chloroform as solvent and optimizing process conditions, uniform nanoporous composite fibers were generated by electrospinning process. TEM images indicate that the MWCNTs were embedded in the fibers as individual elements, highly aligned parallel to one another along the fiber axis, which makes the mechanical load transfer from the polymer matrix to the MWCNT more favorable. Due to the slippage of individual MWCNTs within the fibers the strain at break of composite fibers is significantly enhanced. In addition, the nanopores on the fiber surface provide the effective sites for stress concentration for the plastic deformation to form nanonecking of fibers under tensile load. Combination of these unique features makes the electrospun composite fibers extremely strong and tough. The results from present work may provide a feasible consideration of such electrospun composite fibers for use as the reinforcing elements in a polymer based composite of a new kind.     

Humidity switching properties of sensors based on multiwalled carbon nanotubes/polyvinyl alcohol composite films

Multiwalled carbon nanotubes (CNTs) were used as the conductive filler of composites for switching type humidity sensor. The CNTs were oxidized by mixed acids (H₂SO₄ : HNO₃) at a mild temperature to modify carboxylic acid (COOH) groups on the surface of the nanotubes. The dispersibility of acid treated CNTs (CNTs‐COOH) in water is much improved, which is beneficial for dispersing CNTs in the polyvinyl alcohol (PVA) matrix without external additives. The obtained CNTs‐COOH/PVA sensors show nonlinear response to relative humidity (RH), that is, switching properties. The resistances of the sensors remain constant before 80% relative humidity (RH) and then increase sharply with RH, indicating excellent switching characteristic of the sensors. The 10 wt % CNTs‐COOH/PVA sensor shows a sensitivity (ΔR/Ro) of 32.3 at 100% RH. The humidity switching properties of CNTs‐COOH/PVA are much better than that of pristine CNTs/PVA. The improvements are attributed to the improved balance between the dispersibility of CNTs‐COOH and electrical conductivity of the composite films. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39726.     

磷钨酸/多壁碳纳米管催化合成乙酸正丁酯

利用多壁碳纳米管(MWCNTs)为载体,用浸渍法制备了负载磷钨酸(H3PW12O40,简写为HPW)的复合材料磷钨酸/多壁碳纳米管(HPW/MWCNTs)。磷钨酸/多壁碳纳米管具有很高的催化活性,在磷钨酸负载量为30%,醇酸物质的量比为1.4∶1,催化剂用量为反应物总质量的1.3%,反应温度为117℃,反应时间为3h的条件下,酯化率可达96.08%。