巯基改性碳纳米管的制备与表征

采用一种新颖、高效的方法,将元素硫应用于碳纳米管(CNTs)的表面改性,在CNTs表面通过硫自由基加成随后还原的方法接枝巯基基团,这种改性方法步骤简单、安全,且不会破坏CNTs的内部结构,可以应用于更多领域。利用该方法分别对多壁碳纳米管和单壁碳纳米管进行表面改性,制备了巯基改性碳纳米管,确定了巯基改性多壁碳纳米管的最佳反应条件并采用傅里叶变换红外光谱仪、拉曼光谱仪、热重分析仪和X射线光电子能谱对所制样品进行表征。     

碳纳米管改性聚丙烯复合材料的研究进展

综述了碳纳米管对聚丙烯力学性能改性、电学性能改性、结晶行为改性、阻燃和热稳定性能改性等方面的研究现状,包括单壁碳纳米管和多壁碳纳米管对聚丙烯改性的影响,展望了碳纳米管改性聚丙烯复合材料的发展前景。     

γ射线引发马来酸酐接枝改性多壁碳纳米管

研究了利用高能俺线引发碳纳米管与马来酸酐发生接枝反应，从而达到改性碳纳米管的目的,并利用红外光谱、热重等手段对实验结果进行了表征,结果表明，通过这种方法碳纳米管表面接枝上了有机基团，随着辐照剂量增大接枝上的有机基团量增加，改性后的碳纳米管在水和有机溶剂中的分散性明显增强。     

原子转移自由基聚合法在改性碳纳米管中的应用

原子转移自由基聚合(ATRP)以其适用单体范围广、反应条件温和、分子设计能力强等优点受到各领域科学家的普遍关注。在介绍ATRP原理及特点的基础上,综述了ATRP在改性碳纳米管方面的研究进展,主要包括通过ATRP对碳纳米管进行非共价改性、共价改性以及ATRP与其他技术共同作用的改性方法,对应用ATRP改性碳纳米管的研究方向进行了分析。     

多壁碳纳米管载体的改性及应用

多壁碳纳米管独特的结构和性质(纳米尺寸、介孔结构和大比表面积)使其成为催化剂的良好载体.侧重于催化领域的应用,结合改性的多壁碳纳米管为载体的催化剂在各催化反应中的应用,综述了催化领域中多壁碳纳米管载体的改性方法,指出针对不同的催化反应需采用不同的方法或多种方法相结合对碳纳米管进行表面改性修饰.     

基于碳纳米管的LB膜制备技术

采用混酸处理法对碳纳米管进行了羧化改性，然后进一步运用十八胺双性分子对羧化改性后的碳纳米管进行了表面修饰，深入探讨了基于双性分子表面改性后碳纳米管的LB膜制备过程，并分析了其制备工艺中超声时间、酸量和氧化处理等实验参数对羧化改性的影响，制备出了基于碳纳米管的单层及多层LB膜。初步研究了硅基底表面碳纳米管LB膜的减摩性能．实验结果表明，带有双性分子的十八胺可通过一定的实验条件连接到碳纳米管表面，通过双性分子的亲油性而有效改善碳纳米管在有机溶剂中的溶解性，为碳纳米管LB膜的制备提供了必要条件；此种碳纳米管LB膜可在低载荷下，将硅基底的耐磨性能提高50％以上．     

碳纳米管的功能化修饰及应用研究进展

碳纳米管以其独特的一维结构,优良的力学、电学、光学等性能,受到学术界的广泛关注。但是在实际应用中由于其纳米材料的强大范德华力,碳纳米管很容易聚集在一起。同时碳纳米管不溶于水及有机溶剂,所以限制了其在实际中的应用。因此要对碳纳米管进行表面改性,使其在溶剂中能良好地分散。主要介绍近年来碳纳米管的改性方法,以及在实际应用方面的研究。     

改性碳纳米管处理碳纤维的效果表征

采用浓硫酸/浓硝酸氧化处理多壁碳纳米管(MWCNTs),再将氧化后的碳纳米管与硅烷偶联剂(KH560)进行接枝,制备了硅烷偶联剂表面化学修饰的MWCNTs。在此基础上,将改性前后的碳纳米管分散在环氧树脂体系中,涂覆处理碳纤维。研究处理前后碳纤维力学性能和界面性能的变化。通过红外光谱(FTIR)和透射电镜(TEM)分析,表明KH560已成功接枝到多壁碳纳米管上;通过分散性实验证明了改性后的碳纳米管分散性提高;对处理后的碳纤维进行力学性能测试,并用扫描电镜(SEM)观察分析断面形态变化,结果表明,当碳纳米管的含量为0.5%时,改性碳纳米管处理的碳纤维拉伸强度和拉伸模量分别提高23.83%和7.11%,界面性能增强。     

影响单壁碳纳米管氢气传感器的因素（英文）

单壁碳纳米管用于制造氢气传感器已有几十年的历史。由于单壁碳纳米管与氢气的相互作用很小，因此需采用了多种改性来辅助，改性物包括金属、金属氧化物与聚合物等。一些研究指出，当与碳纳米管上的官能团结合时，改性物可以使响应提高几个数量级。在目前的研究中，已开发了许多新的结构。此外，单壁碳纳米管的直径和手性等结构也会影响氢气探测器的性能。本文对单壁碳纳米管的改性进行了分类，并对其影响因素进行了讨论，旨在为制造高响应度和低检测限的探测器提供支撑。     

水性聚氨酯的改性研究进展EI

水性聚氨酯在胶粘剂及涂料行业中有很好的发展前景。但由于分子中引入了亲水性基团,水性聚氨酯在耐水性、耐溶剂性、耐候性等方面表现较差,需不断对其进行改性研究。文中综述了近年来国内外对水性聚氨酯的一些改性情况,如纳米改性、生物改性、有机氟改性等,并对水性聚氨酯的改性发展方向进行了展望。     

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.     

多壁碳纳米管薄膜离子敏特性的研究

对多壁碳纳米管薄膜传感器的离子敏感特性进行了实验研究.结果表明,经化学修饰的多壁碳纳米管薄膜对离子性气体吸附性能良好,由此而设计的传感器表现出良好的灵敏度和快速的响应.     

A novel assembled carbon black/carbon nanotubes (CB/MWCNT) nano-structured composite for pressure-sensitive conductive silicon rubber (SR)

In this paper, a novel “grape string” carbon black/multi-wall carbon nanotubes (CB/MWCNT) structure was obtained by electro-static assembly method to enhance the resistance stability of the carbon material filled silicone rubber (SR). Carbon black (CB) and multi-wall carbon nanotubes (MWCNT) were surface modified by sulfonic dodecyl benzene sodium and cetyltrimethylammonium bromide to provide negatively charge and positively charge, respectively. Electric conductive sheet of CB/MWCNT/SR composite was obtained by mixing and vulcanizing. The assembly effect and dispersion state of the composites were analyzed by transmission electron microscopy and scanning electron microscopy. The electrical conductivity and dynamic pressure-resistance characteristic of CB/MWCNT/SR with different doping ratio and dosage were tested. The results show that the proper weight ratio 3:2 of CB:MWCNT for electrostatic assembly can cause the stable “grape string” nano-structure. The conductivity and pressure-resistance characteristic are superior when the volume fraction of “grape string” nano-composites reaches 22%, which will provided with less filler fraction and better stress sensitivity, compared with single component carbon black filler.     

Preparation of homogeneous titania coating on the surface of MWNT

Preparation of homogeneous and stable inorganic coatings on the surface of multi-wall carbon nanotubes (CNTs) was studied. Precursor compounds such as titanium (IV) bromide and titanium (IV) chloride were used to cover the surface of CNTs under either solvent-free or solution conditions. As-prepared titania layers were characterized by transmission, scanning electron microscopy and X-ray diffraction techniques. Results revealed that homogenous coverage can be achieved in a controllable way.     

Quantification of ion trapping effect of carbon nanomaterials in liquid crystals

We have determined the ion trapping coefficients of carbon nanomaterials in liquid crystals through the analysis of capacitance-voltage response. The ion trapping coefficient is defined as the ability to trap impurity ions for each carbon nanomaterial and can be used as a referable value to select proper carbon nanomaterials as dopants in liquid crystals. The characterized nanomaterials include multi-wall carbon nanotubes, carbon nanofibers, carbon nanocoils, single-wall carbon nanotubes and fullerenes, respectively. It is found that the multi-wall carbon nanotubes with a tube length of 5-15 μm have the largest ion trapping coefficient and hence serve as the best dopant to suppress the liquid crystal hysteresis.     

TEOS/MWNT-OH杂化涂层的制备及其电化学腐蚀性能的研究

采用溶胶-凝胶(sol-gel)法制备正硅酸乙酯(TEOS)掺杂羟基化多壁碳纳米管(MWNT-OH)杂化涂层,采用电化学测试方法研究其在不同条件下的电化学腐蚀性能,通过场发射扫描电镜观察碳纳米管在涂层中的分布状况。结果表明,热处理温度、不同碳纳米管的加入方式等因素均对涂层性能产生显著的影响。用KH-550乙醇溶液对碳纳米管进行研磨处理后,碳纳米管在硅溶胶体系中呈现良好的均匀分散。涂层的热处理温度是重要因素之一,经过160℃处理后,所得涂层对铝合金基体的防护性能最佳。     

Pyrolytic Synthesis of Carbon Nanotubes from Sucrose on a Mesoporous Silicate

Multi-wall carbon nanotubes were synthesized from sucrose by a pyrolytic technique using mesopourous MCM-41 silicate templates without transition metal catalysts. The nanotubes were examined in the carbon/silicate composite and after dissolution of the silicate. High-resolution transmission electron microscopy study of the multi-wall nanotubes showed them to be 15 nm in diameter, 200 nm in length and close-ended. There was variation in crystallinity with some nanotubes showing disordered wall structures.     

碳纳米管载体改性条件对Pt纳米粒子电催化氧化性能的影响

利用紫外光照射诱导亚甲基蓝改性碳纳米管(MWCNTs), 是一种工艺简单、绿色无毒的改性催化剂碳载体的新方法。本研究以光照改性时间、改性剂(亚甲基蓝)用量和紫外光波长为主要影响因素, 系统研究了不同因素对MWCNTs改性的影响及其对催化剂催化性能的影响。利用透射电子显微镜(TEM)对不同条件下的催化剂形貌进行了表征, 采用循环伏安法(CV)和时间电流法(i-t)等电化学测试手段对催化剂在碱性介质中催化氧化甲醇的催化活性和催化稳定性分别进行了测试, 研究结果表明: 光照时间为6 h、亚甲基蓝用量为10 mg、紫外光波长采用254 nm时, MWCNTs的改性效果最佳, Pt纳米粒子在改性最佳的MWCNTs表面的负载均匀性最好, 所得催化剂的催化性能也最优, 其催化活性是商业Pt/C催化剂的2倍多, 这种改性方式为高活性、低成本燃料电池阳极催化剂的研究提供了新方法。     

Effect of functionalized carbon nanotubes on the mechanical properties of epoxy-based composites

Abstract

In this research, composites reinforced with multi-walled carbon nanotubes (MWCNTs) in terms of their capability of absorbing energy during ballistic impact and tensile test were investigated. In order to investigate the effect of functional groups on mechanical properties of multi-wall carbon nanotubes composites, multi-walled carbon nanotubes were functionalized by COOH and NH₂. In order to investigate the penetration resistance of produced composites, the ballistic impact test with the high velocity was used. Results of the ballistic impact test imply that composites which benefit from carbon nanotubes with the carboxylic functional group have the highest value of the energy absorption. Results of the tensile test indicate, the interaction between carbon nanotubes with the carboxylic agent and the polymer matrix is much better. The ultimate stress for the sample containing nanotubes with hydroxyl functional group is 55% higher compared with the sample which does not contain any nanotubes. Reinforced composite samples which contain carbon nanotubes with the carboxylic functional group absorb 57.63% of the projectile energy and represent a better performance compared to the sample without nanotubes and the sample which consists of nanotubes with the amine functional group. The results of this study show that, uniform dispersion of nanotubes in the polymer matrix can profoundly affect mechanical properties especially the tensile strength. By functionalizing nanotubes and creating suitable functional groups, the cohesion between nanotubes and the matrix can be improved.