碳纳米管增强PA6纤维的性能

将碳纳米管(CNT)在分散剂或分散剂和聚合物(PA6)载体中处理后制备出两种母粒,将其作为增强材料分别和PA6切片熔融共混纺丝,制备出碳纳米管的增强PA6纤维,研究其结构和力学性能.CNT含量低于0.5%(质量分数)时,使用两种母粒制备出的纤维强度和模量都提高,NT含量为0.03%时增强的效果最好.由碳纳米管和分散剂组成的母粒增强效果更好,NT的含量为0.03%时就能使PA6纤维的强度和模量分别提高23%和76%.这种增强纤维是一种微纤增强纤维,纳米CNT在纤维中均匀分散且沿着纤维轴的方向取向.这种结构能有效地转移载荷,具有增强作用,且取向性越好,增强效果越好.     

聚氨酯/多壁碳纳米管抗静电涂料的制备与性能研究

为研究采用多壁碳纳米管在聚氨酯清漆中的抗静电效果,制备了一系列抗静电涂料,结果表明聚氨酯/多壁碳纳米管涂料可以满足抗静电需要(即表面电阻率在105～109Ω范围).碳纳米管含量与电性能曲线为典型渗流曲线,其渗流阈值为2wt％.在较低的添加量(2wt％)时,碳纳米管表电性能优于炭黑,当添加量较高(5wt％)时,其电性能反而比炭黑差,采用适当的酸处理的方法可以进一步提高聚氨酯/多壁碳纳米管的导电性能.     

碳纳米管对三种有机抗静电剂性能的改进

通过碳纳米管来改进有机抗静电剂的性能,用于聚合物抗静电纤维.碳纳米管分散在有机抗静电剂载体PR86,TS40和TS51中制成复合抗静电剂CNTs/PR86,CNTs/TS40和CNTs/TS51,与聚丙稀(PP)混纺制备CNTs/PR86/PP纤维,CNTs/TS40/PP纤维和CNTs/TS51/PP纤维.通过对摩擦静电荷的测试结果表明,含碳纳米管的有机抗静电剂相对于纯有机抗静电剂更进一步提高了丙纶纤维的抗静电能力.     

复合型导电纤维的制备及性能

选用实验室自制的白色导电Ti O_2熔融造粒制备导电母粒,然后通过复合熔融纺丝技术制备4种不同截面形貌的白色导电纤维,采用扫描电镜、X射线衍射仪和热重分析仪等对其结构和性能进行详细表征。通过与共混型导电纤维对比发现,4种复合型导电纤维的拉伸强度明显提高,同时纤维体积电阻率下降了3个数量级,复合纺丝能够有效提高纤维的综合性能;抗静电性能研究发现,织物抗静电性与纤维导电性不呈正比关系,但其与复合导电纤维中导电部分的尖锐程度和裸露表面积有一定关系:导电部分形貌越尖锐,裸露表面积越大,纤维抗静电性能越好;进一步研究表明,对称腰形复合型导电纤维综合性能最优,可应用于抗静电织物的制备。     

碳纳米管类型对CNTs/Lyocell复合纤维结构与性能的影响

分别采用单壁碳纳米管（SWNTs）和多壁碳纳米管（MWNTs）这两种碳纳米管（CNTs）制备不同的CNTs/Lyocell复合纤维,探讨了碳纳米管类型对复合纤维的结构与性能的影响。结果表明,碳纳米管类型并未影响CNTs/Lyocell纤维的结晶结构,质量分数为1%的SWNTs或MWNTs在Lyocell基体中分布都比较...     

水相悬浮聚合制备MWCNTs/PAN复合微球及其电纺纤维

先用Fenton试剂（过氧化氢/硫酸亚铁）对多壁碳纳米管进行改性处理（-fMWCNTs）,再通过水相悬浮聚合法制备了多壁碳纳米管/聚丙烯腈（-fMWCNTs/PAN）复合微球,用静电纺丝技术制备了-fMWCNTs/PAN复合纤维膜。通过扫描电镜（SEM）、热重分析仪（TGA）和万能试验机研究了-fMWCNTs对电纺纤维...     

聚乳酸/碳纳米管导电复合纤维用于心肌组织工程的研究

采用静电纺丝技术制备聚乳酸/碳纳米管导电纤维膜,因多壁碳纳米管(MWCNTs)的加入,使得所制备纤维膜具有良好的力学和导电性能。针对心肌细胞(CMs)的特点,通过改变碳纳米管的加入量及纤维的定向性,得出适合CMs生长的导电复合纤维支架为AC3支架(含3%MWCNTs),对于心肌组织修复具有较大的潜力。     

抗静电增透母粒在LLDPE中的应用研究

采用抗静电剂与纳米粉体复配制备抗静电母粒的方式,研究了母粒添加量与纳米粉体对薄膜光学、力学及抗静电性能的影响,并利用SEM对抗静电剂及纳米粉体在薄膜中的形貌进行了表征。结果表明,薄膜性能随母粒添加量的变化而变化,当添加量为3%时,薄膜性能达到最佳,其雾度值降低到11%左右,表面电阻率达到109Ω,力学性能提高;母粒中纳米粉体的加入导致薄膜透明度及力学性能有所提高,表面电阻率更低,抗静电持效性更长。     

两种不同的复合抗静电增透母粒在LLDPE中的应用研究比较

采用抗静电剂与纳米粉体复配制备抗静电母粒的方式,研究了SiO_2复合抗静电增透母粒和BaSO_4复合抗静电增透母粒对薄膜雾度、透光率及抗静电性能的影响,并利用SEM对抗静电剂及纳米粉体在薄膜中的形貌进行了表征。结果表明,添加BaSO_4复合抗静电增透母粒的薄膜的雾度低于空白试样,对薄膜的透明性有一定的改善;添加SiO_2和BaSO_4的薄膜试样表面电阻率分别达到了1010Ω和109Ω,抗静电效果很好。从总体来看,添加BaSO_4薄膜试样在透明性及抗静电时效性都较SiO_2更好。     

MFC增强碳纳米纸的制备及其电磁屏蔽效能

为提高碳纳米纸(BP)力学性能,将微纤化纤维素(MFC)与多壁碳纳米管(MWCNT)混合,采用真空抽滤的方法制备MFC/BP。详细研究了MFC/BP的微观形貌、力学性能、电学性能、电磁屏蔽效能。研究表明,MFC均匀分散在碳纳米管中,形成了纤维骨架,碳纳米管相互穿插缠绕分布在纤维骨架周围形成网状结构。随着MFC含量的增加,MFC/BP的力学性能明显提高。当MFC与MWCNT质量比为1/1时,碳纳米纸的拉伸强度为11.76 MPa,比纯碳纳米纸提升了979%;在8.2～12.4 GHz频段内,碳纳米纸(厚度约55μm)的电磁屏蔽效能为24～30 dB。     

碳纳米管应用于聚合物抗静电纤维的研究

基于聚合物与抗静电载体混纺而形成的“海岛”型内部结构,通过极化放电而消除静电的抗静电原理,将碳纳米管应用于聚合物抗静电纤维。摩擦静电荷测试结果显示,碳纳米管由于具有优异的导电性,强化抗静电载体周围的电场,从而显著地提高了聚合物纤维的抗静电能力。经过改性处理的碳纳米管,如空气活化和酸处理等,抗静电效果更加显著,尤其是金属沉积处理的碳纳米管,抗静电效果最为显著。说明碳纳米管在抗静电聚合物纤维领域是很有应用前途。     

碳纳米管对纳米炭复合纤维结构与性能的影响研究

采用不同方法将多壁碳纳米管(MWNTs)混合于中间相沥青中,利用氮压式单孔纺丝机进行纺丝,经预氧化、碳化后制得了纳米炭复合纤维,对比研究了混合方式对纳米炭复合纤维的结构和性能的影响.研究结果表明,MWNTs的加入最终改变了纤维的微观结构,尤其经浓酸处理后显著提高了纳米炭复合纤维的力学性能.     

Some of the physical and mechanical properties of cement composites manufactured from carbon nanotubes and bagasse fiber

The objective of this investigation was to evaluate physical and mechanical properties of experimental cement type panels made from multi-wall carbon nanotubes (MWCNTs) and bagasse fiber. Three levels of MWCNTs, namely 0.5 wt.%, 1 wt.% and 1.5 wt.% were mixed with 10 wt.% and 20 wt.% of bagasse fiber in rotary type mixer. Thickness swelling, water absorption, bending characteristics and impact strength of the samples were evaluated. Based on the findings in this work the water absorption and thickness swelling of the nanocomposites decreased with increasing amount of the multi-wall carbon nanotubes content in the panels from 0.5% to 1.5%. On the other hand flexural modulus and impact strength of the panels were enhanced with increased percentage of carbon nanotubes. Panels having 0.5% MWCNTs exhibited the highest impact strength. Overall dimensional stability and strength properties of the samples were adversely influenced with increased amount bagasse fiber in the samples. It appears that using lower percentage of bagasse fiber or application of heat or chemical treatment to the raw material should be considered to improve negative influence of bagasse fiber on properties of the panels.     

Hierarchical composites of carbon nanotubes on carbon fiber: Influence of growth condition on fiber tensile properties

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.     

Mobility of carbon nanotubes in high electric fields

The influence of electric fields on carbon nanotubes is experimentally demonstrated. Alignment of nanotubes along field lines, directed motion of nanotubes between electrodes separated by several thousand micrometers, and impressive solid-state actuation behavior of nanotube-embedded structures are demonstrated, taking into account the polarization and charging of the nanotubes. These effects are reported for long strands of nanotubes, nanotubes dispersed on substrates, and nanotube-embedded polymer strips. The relative magnitude of the field responsible for polarization and directed motion was found to be dependent on the morphology of the nanotubes used. These observations may foreshadow novel electromechanical applications for nanotube elements.     

Synthesis and characterization of alumina-coated carbon nanotubes and their application for lead removal

Alumina-coated multi-wall carbon nanotubes were synthesized and characterized by scanning electron microscopy, X-ray diffraction, and FTIR. They were used as an adsorbent for the removal of lead ions from aqueous solutions in two modes, batch and fixed bed. In the batch mode, experiments were carried out to investigate the effect of contact time, agitation speed, adsorbent dosage and solution pH on the removal of lead. The coated nanotubes exhibit better removal ability over uncoated. For fixed-bed columns, thickness of the layer and flow rate were investigated. Increasing the thickness and decreasing the flow rate enhanced the removal of lead. The prepared adsorbent displayed the main advantage of separation convenience when a fixed-bed column was used compared to the batch adsorption treatment.     

The formation and characterization of palladium nanowires in growing carbon nanotubes using microwave plasma-enhanced chemical vapor deposition

Multi-wall carbon nanotubes were synthesized on electroplated palladium nanoclusters using a microwave plasma-enhanced chemical vapor deposition system in a mixture of methane and hydrogen as precursors. During the synthesis, Pd was melted to fill up the growing multi-wall carbon nanotubes. A growth mechanism was proposed to describe the Pd filling phenomenon. The multi-wall carbon nanotubes could be burned in oxygen plasma and the filled Pd nanowires could thus be collected. The surface morphology of electroplated Pd clusters and the nanostructure of multi-wall carbon nanotubes with filled Pd nanowires were examined by scanning electron microscopy and transmission electron microscopy, respectively. Raman spectra were used to study the first- and second-order signals of multi-wall carbon nanotubes. Bamboo-shaped carbon nanotubes free of filled Pd were observed under a pure methane atmosphere.     

Covalent coupling of polyacrylic acid coated magnetic-nanoparticles to multi-wall carbon nanotubes for manipulation targets

This research effort investigated the chemical heterojunction between magnetic nanoparticles coated with polyacrylic acid and multi-wall carbon nanotubes (MWCNTs). Here, magnetic nanoparticles were covalently attached to open-ended nanotubes in the presence of diclohexylcarbodiiimide. Initial evidence demonstrated that short functionalised multi-wall nanotubes can be continuously connected at their terminals ends to build-up relatively large nanostructures. It has also been shown that magnetic-carbon nanotubes (CNTs) systems exhibited defined arrangements due to the influence of magnetic fields. Indeed, linear arrays of CNTs interconnected through magnetic nanoparticles were prone to be manipulated in the presence of a magnetic device. A potential application of these kind of magnetic nanostructures was shown here by successfully manipulating agarose beads in a buffer solution. These results suggest that the use of continuously connected magnetic nanostructures with non-modified sidewall surfaces will find potential applications in the area of bio-sensing, force transduction and cancer screening-manipulation among many others.     

抗静电增强尼龙66研制

以阴离子和非离子型抗静电剂组成复合抗静电体系，用玻璃纤维为增强剂，研制成具有良好抗静电和机械性能优良的尼龙66；介绍了抗静电复合体系及玻璃纤维含量对抗静电增强尼龙性能的影响。