共查询到19条相似文献,搜索用时 203 毫秒
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功能化碳纳米管的电磁性能研究及进展 总被引:3,自引:0,他引:3
碳纳米管是最近发展起来的一种结构独特,性能优异的新材料,已成为当今物理、化学、材料等领域共同关注的课题.而碳纳米管的功能化更是为我们开辟了一个广阔的研究领域.本文总结了近十多年来功能化碳纳米管的研究进展,并侧重对功能化碳管的合成方法及电磁特性以及应用进行了评述. 相似文献
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通过4种键连方式将苯环共价连接到超晶胞为1×1×3的锯齿型单壁碳纳米管CNT(8,0)上.在密度泛函理论基础上,通过Siesta软件计算苯环共价功能化碳纳米管的几何结构、能带结构、态密度和波函数,分析键连方式对碳纳米管电性的影响.结果表明苯环通过4种键连方式共价功能化的碳纳米管都是在Γ点具有直接带隙的半导体.其中直接键连和酰胺键连得到的苯环功能化碳纳米管在费米能级附近产生杂质带,比纯CNT带隙减小约0.4e V.而通过2个亚甲基键连和吡咯烷键连2种方式功能化的碳纳米管,其带隙仅比纯CNT带隙减小0.1~0.15e V. 相似文献
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电弧法自制碳纳米管原子力显微镜针尖,对其末端进行功能化修饰,然后测量配体-受体之间的作用力。运用没有功能化修饰的碳纳米管针尖与修饰有亲和素分子的基底进行接触测量时,没有粘滞力出现;而运用末端修饰生物素分子的碳纳米管针尖测量时,有粘滞力产生。功能化的碳纳米管针尖直接测得的粘滞力均大约200pN,此值符合一对配体生物素和受体亲和素之间的作用力。这一结果很难用传统的针尖获得,功能化修饰的碳纳米管针尖能够克服传统针尖在力测量中的局限,在生物学和化学领域有着广泛的应用前景。 相似文献
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采用液相沉积方法分别制备了聚乙烯亚胺功能化和聚4-乙烯基吡啶功能化的碳纳米管催化剂,利用N2吸附/脱附、透射电子显微镜(TEM)、热重分析(TG)以及酸碱滴定等方法对所得催化剂的结构和碱性进行了表征,测试了其对于苯甲醛和丙二腈的Knoevenagel缩合反应的催化性能。结果发现,聚乙烯亚胺功能化的碳纳米管具有比聚4-乙烯基吡啶功能化的催化剂更高的碱催化能力。对碳纳米管进行强酸预处理可增加其与修饰剂的相互作用,虽然会降低其碱催化活性,但却可使其稳定性大大提高。 相似文献
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采用液相沉积方法分别制备了聚乙烯亚胺功能化和聚4-乙烯基吡啶功能化的碳纳米管催化剂,利用N2吸附/脱附、透射电子显微镜(TEM)、热重分析(TG)以及酸碱滴定等方法对所得催化剂的结构和碱性进行了表征,测试了其对于苯甲醛和丙二腈的Knoevenagel缩合反应的催化性能。结果发现,聚乙烯亚胺功能化的碳纳米管具有比聚4-乙烯基吡啶功能化的催化剂更高的碱催化能力。对碳纳米管进行强酸预处理可增加其与修饰剂的相互作用,虽然会降低其碱催化活性,但却可使其稳定性大大提高。 相似文献
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碳纳米管的化学修饰以及作为润滑油添加剂的摩擦学性能研究 总被引:5,自引:0,他引:5
采用硫酸和硝酸混合酸对催化裂解法(CVD法)制备的多壁碳纳米管(MWNNTs)进行纯化,然后运用硬脂酸对碳纳米管进行表面修饰,并研究了硬脂酸修饰后的碳纳米管的表面状况以及作为润滑油添加剂的摩擦学行为.实验结果表明,在硫酸催化剂作用下,通过酯化反应碳纳米管能够被硬脂酸包覆,并且硬脂酸修饰的碳纳米管作为润滑油添加剂能够显著提高基础油的减摩抗磨性能,当添加量为0.15%左右时,润滑油的减摩抗磨性能最佳,与基础油相比可以使摩擦系数下降10%左右,磨损量下降30%~60%. 相似文献
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Masahito Sano Ayumi Kamino Junko Okamura Seiji Shinkai 《Journal of inclusion phenomena and macrocyclic chemistry》2001,41(1-4):49-52
As-grown, string-shaped single-walled carbon nanotubes were transformed into other shapes by applications of organic chemistry. Cutting carbon nanotubes in strong acids affords oxygen-containing groups at both ends of the open tubes. These groups were utilized for ring-closure reactions in very dilute conditions. Atomic force microscopy reveals ring-shaped nanotubes with a mean diameter of 540 nm as products. Also, the end groups were used to react with the surface amine groups of PAMAM dendrimer. It gave star-shaped structures in which straight nanotubes are radiating from dendrimer centers. These experiments clearly demonstrate that covalent chemistry is useful for construction of super-structured carbon nanotubes. 相似文献
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A facile and general method was described to coat six types of multi-walled carbon nanotubes, functionalized by either noncovalent or covalent way, with smooth silica shells. 3-Aminopropyltriethoxysilane(APTES) and pH value play important roles in the coating process and the thickness of silica shell could be controlled by the added amount of silicon alkoxides. After the removal of multi-walled carbon nanotubes by calcination, the silica nanotubes were successfully prepared. 相似文献
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Multiwalled carbon nanotubes have been entrapped in a porous monolithic chromatographic support. This support was used for the covalent immobilization of the arginase enzyme a novel target in hypertension. The effect of the nanotube (NT) amount into the monolith was analyzed. The obtained results demonstrated the ability of carbon nanotubes to increase significantly the performance of this novel bioactive support. 相似文献
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The synthesis of drug delivery system for pharmaceutical substances, represented by modified shortened single-walled carbon nanotubes, was realized. The synthesis was carried out via covalent grafting of water soluble linker to the graphene surface of single-walled carbon nanotubes, and resulted in stabilization of synthesized substance in water suspension.
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We present a theoretical study of the electronic and mechanical properties of graphyne-based nanotubes (GNTs). These semiconducting nanotubes result from the elongation of one-third of the covalent interconnections of graphite-based nanotubes by the introduction of yne groups. The effect of charge injection on the dimensions of GNTs was investigated using tight-binding calculations. Low amounts of electron injection are predicted to cause qualitatively different responses for armchair and zigzag graphyne nanotubes. Although the behavior is qualitatively similar to the usual carbon nanotubes, the charge-induced strains are predicted to be smaller for the GNTs than for ordinary single walled carbon nanotubes. 相似文献
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Dr. Laura Cabana Dr. Arántzazu González‐Campo Dr. Xiaoxing Ke Prof. Gustaaf Van Tendeloo Dr. Rosario Núñez Dr. Gerard Tobias 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(47):16792-16795
As‐produced single‐walled carbon nanotubes (SWCNTs) tend to aggregate in bundles due to π–π interactions. Several approaches are nowadays available to debundle, at least partially, the nanotubes through surface modification by both covalent and noncovalent approaches. Herein, we explore different strategies to afford an efficient covalent functionalization of SWCNTs with cobaltabisdicarbollide anions. Aberration‐corrected HRTEM analysis reveals the presence of metallacarboranes along the walls of the SWCNTs. This new family of materials presents an outstanding water dispersibility that facilitates its processability for potential applications. 相似文献
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A serendipitous finding that ionic liquids gel with carbon nanotubes has opened a new possibility of ionic liquids as modifiers for carbon nanotubes. Upon being ground into ionic liquids, carbon nanotube bundles are untangled, and the resultant fine bundles form a network structure. This is due to the possible specific interaction between the imidazolium ion component and the pi-electronic nanotube surface. The resultant gelatinous materials, consisting of highly electroconductive nanowires and fluid electrolytes, can be utilized for a wide variety of electrochemical applications, such as sensors, capacitors, and actuators. Ionic liquids allow for noncovalent and covalent modifications of carbon nanotubes and fabrication of polymer composites with enhanced physical properties. The processing of carbon nanotubes with ionic liquids is not accompanied by the disruption of the pi-conjugated nanotube structure and does not require solvents; therefore it can readily be scaled up. This article focuses on new aspects of ionic liquids for designer soft materials based on carbon nanotubes. 相似文献