单壁碳纳米管/六角钡铁氧体复合材料的微波吸收性能

用电弧法制备含铁的单壁碳纳米管(SWCNTs), 并将其提纯之后掺杂到用溶胶-凝胶自燃法制备的M型六角钡铁氧体(BaFe₁₂O₁₉)纳米晶粉体中, 得到了具有网状结构的复合材料。利用同轴法测试了样品的电磁参数, 研究了不同混合比SWCNTs/BaFe₁₂O₁₉ 复合材料的吸波性能。结果表明: 复合粉体SWCNTs/BaFe₁₂O₁₉的磁损耗主要是由于自然共振和交换共振引起的; 当掺杂2%(质量分数)SWCNTs时, 微波反射衰减最大值可以达到 24.85 dB, 高于10 dB的频带宽度可以达到6.30 GHz, 具有较宽的吸波频段。      

Modal analysis of carbon nanotubes and nanocones using FEM

Modal analysis of single-walled carbon nanotubes (SWCNTs) and nanocones (SWCNCs) was performed using a finite element method (FEM) with ANSYS. The vibrational behaviors of fixed beam and cantilever SWCNTs with different section types of a circle and an ellipse were modeled using three-dimensional elastic beams of carbon bonds and point masses. Also, the vibrational behaviors of fixed beam and cantilever SWCNCs with different disclination angles of 120°, 180°, and 240° were modeled using the same method. The beam element natural frequencies were calculated by considering the mechanical characteristics of the covalent bonds between the carbon atoms in the hexagonal lattice. Each mass element of the carbon atoms was assigned as a point mass at the nodes of the FEM elements. The natural frequencies of zigzag and armchair SWCNTs and SWCNCs were also computed. There were some differences between the findings obtained in this study and the molecular structural mechanics data available in the literature. The natural frequencies of SWCNCs were estimated depending on the geometrical type and disclination angle with different boundary conditions. The natural frequencies of the SWCNCs with disclination angles of 120°, 180°, and 240° increased significantly at higher modes of vibration.     

High-quality single-walled carbon nanotubes synthesis by hot filament CVD on Ru nanoparticle catalyst

We investigated the single-walled carbon nanotubes (SWCNTs) growth on Ru nanoparticle catalyst via hot filament assisted chemical vapor deposition (HFCVD) with two independent W filaments for the carbon precursor (methane) and the hydrogen dissociation respectively. The Ru nanoparticles were obtained following a two-step strategy. At first the growth substrate is functionalized by silanisation, then a self assembly of a ruthenium porphyrin complex monolayer on pyridine-functionalized metal oxide substrates. We have studied the impact of the filaments power and we optimized the SWCNTs growth temperature. The as grown SWCNTs were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and Raman spectroscopy. It was found that the quality, density and the diameter of SWCNTs depends on the filament and growth temperature. Results of this study can be used to improve the understanding of the growth of SWCNTs by HFCVD.     

Hybridization kinetics and thermodynamics of DNA adsorbed to individually dispersed single-walled carbon nanotubes

Hybridization of DNA adsorbed to single-walled carbon nanotubes in solution has much slower kinetics than free solution DNA, and can be detected through a blue shift in the near-infrared nanotube fluorescence. Adsorption of the receptor DNA strand to the nanotube surface is consistent with models of polyelectrolyte adsorption on charged surfaces, introducing both entropic (46.8 cal mol(-1) K(-1)) and activation energy (20.4 kcal mol(-1)) barriers to the hybridization, which are greater than free solution values (31.9 cal mol(-1) K(-1) and 12.9 kcal mol(-1)) at 25 degrees C. The increased hybridization barriers on the nanotube result in exceedingly slow kinetics for hybridization with t(1/2)=3.4 h, compared to the free solution value of t(1/2)=4 min. These results have significant implications for nanotube and nanowire biosensors.     

Effects of boron-doping on the morphology and magnetic property of carbon nanotubes

Boron carbide nanotubes (nano-fibers) was prepared by B powder and carbon nanotubes (CNTs) at high temperature in a vacuumed quartz tube. The morphology, microstructure, component and magnetic property of samples were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and magnetic property measurement system (MPMS) controller. The results showed that B-doping CNTs have great difference in the morphology and magnetic property from those of pristine CNTs. __________ Translated from Journal of Functional Materials, 2006, 37(9): 1398–1400 (in Chinese)     

SDBS修饰碳纳米管及其增强聚乳酸复合材料的制备与表征

采用十二烷基苯磺酸钠(SDBS)对碳纳米管进行表面修饰,并以其为增强体,利用溶剂蒸发法制备了碳纳米管/聚乳酸复合材料.采用红外吸收光谱、偏光显微镜、扫描电镜及拉伸实验研究了SDBS修饰的碳纳米管表面形貌和结构以及碳纳米管/聚乳酸复合材料的链结构、聚集态结构和力学性能.SDBS修饰可使碳纳米管均匀分散于有机溶剂中,并改善...     

Supported Pt-particles on multi-walled carbon nanotubes with controlled surface chemistry

Multi-walled carbon nanotubes (MWCNTs) were functionalized by HNO₃ hydrothermal oxidation at 200 °C. The degree of surface functionalization was described by an exponential function in terms of HNO₃ concentration. Very small Pt particles, with mean particle size of 1.7 ± 0.3 nm, could be supported on the surface of pristine MWCNTs and also on MWCNTs treated with HNO₃ concentrations up to 0.20 mol L^− 1, while a broader range of particle sizes, and larger Pt particles (3.4 ± 1.3 nm) were obtained on the MWCNTs treated with a higher HNO₃ concentration (0.30 mol L^− 1). Therefore, the amounts of surface groups and Pt particle sizes can be selected by tuning the HNO₃ concentration used in the hydrothermal treatment.     

氨化碳纳米管接枝生物分子(蛋白质和DNA)

报告-种氨基功能化处理的多壁碳纳米管(f-MWCNTs)用于生物分子[如牛血浆蛋白素(BSA)蛋白质及脱氧核醣核酸(DNA)]的接枝处理高效方法.以苯-二茂铁喷入氩氛炉于～850 ℃裂解制得MWCNTs,,而后向纳米管表面导入羧基化合物,再以氨基基团对MWCNTs,进行功能化处理.该过程包括:乙二胺与羧基基团直接结合,经酰胺化引入胺基基团.对制得的MWCNTs、 f-MWCNTs以及由BSA蛋白质和DNA接枝的氨化f-MWCNTs等样品,采用SEM、TEM、FTIR进行表征.结果表明:生物分子(BSA蛋白质和DNA)接枝于氨化的f-MWCNTs.     

A study on the bactericidal properties of Cu-coated carbon nanotubes

A Cu layer was coated on carbon nanotubes (CNTs) by ion beam-assisted deposition (IBAD). Standard agar dilution method was used to evaluate the bactericidal rate against E. coli and S. aureus bacteria. The structure and chemical states of the Cu-coated CNTs were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results show that the Cu-coated CNTs possess a very high bactericidal rate. In comparison with the Cu-coated pyrolytic carbon sample, the Cu-coated CNTs show much stronger bactericidal property.     

碳纳米管/羟基磷灰石复合材料的制备及表征

以含钴介孔分子筛为催化剂、乙醇为碳源, 采用CVD法制备碳纳米管(CNTs)。通过原位合成法制备一系列不同碳纳米管含量的碳纳米管/羟基磷灰石(CNTs/HA)复合材料。分别采用XRD、FTIR、TEM、N₂吸附-脱附和Raman光谱等分析手段, 对所合成CNTs/HA复合材料的晶相、结构、形貌和比表面积等进行了表征。同时研究了碳纳米管的添加量对所合成CNTs/HA复合材料形貌的影响。XRD与Raman结果表明, 所得CNTs/HA复合粉体中仅有CNTs与HA两种物相, 纯度较高, 结晶度较好; TEM结果显示, CNTs/HA复合材料中CNTs表面均匀包裹着一层纳米级的针状HA晶粒, 两者形成了较强的界面结合, 且当CNTs与HA的质量比为3:17时, CNTs与HA形成最佳结合状态; N₂吸附-脱附表征结果表明, 与HA的比表面积相比, CNTs/HA复合材料具有较高比表面积。     

机械混炼对碳纳米管/丁苯橡胶复合材料的影响

为研究机械混炼对碳纳米管(CNTs)/粉末丁苯橡胶(SBR)复合材料性能的影响,从而获得性能优异的CNTs/SBR复合材料,联合采用喷雾干燥法和机械混炼法,制备高填充量CNTs/SBR复合材料.将喷雾干燥法制备的CNTs/粉末SBR复合材料在开炼机上机械混炼,对比分析混炼前后试样的物理和力学等相关性能,并对其微观形貌进行检测.结果表明,机械混炼使CNTs获得进一步的分散,与SBR基体间作用力得到增强,与混炼前相比,混炼后试样的玻璃化转变温度、交联度和常规力学性能均得到提高,当CNTs加入量为50phr时,混炼后复合材料的拉伸强度和撕裂强度分别为13.1MPa和39.8kN/m,比混炼前试样分别提高了约80%和20%.     

定向碳纳米管的化学气相沉积制备法

报道了一种简便有效的合成定向碳纳米管 (CNTs)的化学气相沉积 (CVD)制备方法。以铁为催化剂 ,乙炔为碳源 ,采用单一反应炉 ,直接在石英基底上沉积催化剂颗粒薄膜 ,成功合成了定向性好、管径均匀的高质量大密度的碳纳米管     

以预锂化多壁碳纳米管为负极的锂离子电容器性能

采用内部短路方式对多壁碳纳米管负极进行不同程度的预嵌锂处理,预嵌锂时间为5,30,60min,以预嵌锂多壁碳纳米管极片作为负极,活性炭极片作为正极,组装成锂离子电容器。利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)对多壁碳纳米管及电极极片进行表征分析,采用恒流充放电(GCD)和交流阻抗谱(EIS)研究预嵌锂多壁碳纳米管负极和未预嵌锂处理多壁碳纳米管负极锂离子电容器的性能。电化学测试结果表明,多壁碳纳米管负极预嵌锂大幅提高了电容器充放电性能,对比未嵌锂多壁碳纳米管电容器,在相同的电流密度下(100mA/g),能量密度提高400%。预嵌锂60min,电流密度100mA/g时,其比容量达到57F/g。在电流密度为100～3200mA/g范围内,其最高能量密度与功率密度分别达到90Wh/kg,4130W/kg。1000次充放电循环后,容量保持率维持在85%以上,表现出良好的超级电容器性能。     

镀银碳纳米管的抗菌性研究

用离子束辅助沉积(IBAD)方法在碳纳米管表面制备银膜.用琼脂平板法测试了抗菌率,测试菌种为革兰氏阴性大肠杆菌(E.coil)和革兰氏阳性金黄色葡萄球菌(S.aureus);用扫描电子显微镜(SEM) 观测了镀银碳纳米管的微观形貌;用能量散射X射线谱(EDX)分析了镀银碳纳米管表面元素的原子百分比;用X射线光电子能谱(XPS) 分析了镀银碳纳米管的表面元素的价态.研究结果表明,镀银碳纳米管具有优良的抗菌性能,且比在热解碳上镀银样品的抗菌性强.     

Improved conductivity and capacitance of interdigital carbon microelectrodes through integration with carbon nanotubes for micro-supercapacitors

In the last decade,pyrolyzed-carbon-based composites have attracted much attention for their applications in micro-supercapacitors.Although various methods have been investigated to improve the performance of pyrolyzed carbons,such as conductivity,energy storage density and cycling performance,effective methods for the integration and mass-production of pyrolyzed-carbonbased composites on a large scale are lacking.Here,we report the development of an optimized photolithographic technique for the fine micropatterning of photoresist/chitosan-coated carbon nanotube (CHIT-CNT) composite.After subsequent pyrolysis,the fabricated carbon/CHIT-CNT microelectrode-based micro-supercapacitor has a high capacitance (6.09 mF.cm-2) and energy density (4.5 mWh.cm-3) at a scan rate of 10 mV.s-1.Additionally,the micro-supercapacitor has a remarkable long-term cyclability,with 99.9％ capacitance retention after 10,000 cyclic voltammetry cycles.This design and microfabrication process allow the application of carbon microelectromechanical system (C-MEMS)-based micro-supercapacitors due to their high potential for enhancing the mechanical and electrochemical performance of micro-supercapacitors.     

卵磷脂改性磁性碳纳米管的制备及生物相容性

采用生物活性两亲性分子卵磷脂(PC), 对制备的磁性碳纳米管(Fe₃O₄/CNTs)进行非共价修饰, 得到了内部为疏水端、外部为带电亲水基团的类膜结构包覆的改性复合材料Fe₃O₄/CNTs-PC。在溶液中带电基团通过溶剂化作用及亲水作用, 在复合材料表面形成水化层, 提高复合材料的自由水含量。在蛋白质吸附实验与复钙化凝血时间评价中, Fe₃O₄/CNTs-PC对蛋白质吸附量仅为0.1368 mg/mg, 复钙化凝血时间延长至324 s, 具有很好的生物相容性。     

用单壁纳米碳管制备葡萄糖生物传感器的研究

以单壁纳米碳管为代表材料,对利用纳米碳管制备葡萄糖生物传感器中纳米碳管的作用和纳米碳管修饰电极的方法、酶的固定化方法及电极种类等因素对传感器性能的影响进行了研究.研究结果表明,纳米碳管的加入能有效地改善传感器的电化学性能,利用二茂铁和单壁纳米碳管共同修饰电极所制得的传感器的性能要好于仅用单壁纳米碳管修饰电极制得的传感器.在酶的固定化方法中,戊二醛交联法要略好于明胶包埋法;而利用铂电极制备出的生物传感器对葡萄糖的响应电流要明显高于利用金电极和玻碳电极制备出的生物传感器.这些结论对于开发纳米碳管在生物传感领域及生命科学相关领域的应用有参考价值.     

PMMA/Cu碳纳米管复合材料热学特性实验

CNT的准一维中空特性和优异的长径比让其成为优异的导热材料。利用酸化的多壁碳纳米管,分别采用原位聚合和粉末冶金的方法制备MWCNTs/聚甲基丙烯酸甲酯(PMMA),MWCNTs/铜(Cu),以及MWCNTs/Cu/PMMA复合样品。实验结果表明,1.3%(质量分数)MWCNTs/PMMA和1.3%(质量分数)MWCNTs/1.3%(质量分数)Cu/PMMA相比纯PMMA的导热率分别提高8%和29.14%;2%(体积分数)MWCNTs/Cu相比纯Cu的导热率提高8.47%。利用SEM图观察到MWCNTs分散在基底中,并从Raman光谱得到MWCNTs的G带和D带峰。     

Curing behavior and kinetic analysis of epoxy resin/multi-walled carbon nanotubes composites

The effect of multi-walled carbon nanotubes (MWNTs), both amino-functionalized (f-MWNTs) and unfunctionalized (p-MWNTs) on the curing behavior of epoxy resin (EP) cured with triethanolamine (TEA), was investigated using differential scanning calorimetry (DSC). Because the triethylenetetramine (TETA) grafted on the f-MWNTs could act as curing agent and the produced tertiary amine as negative ionic catalysts of curing reaction of EP, so the activation energy of the EP/TEA system was decreased by the addition of f-MWNTs. Viscosity played a key role in the curing behavior of the EP/TEA/MWNTs system, for high viscosity of the EP/TEA/MWNTs system could hinder the motion of the functional groups. The curing heat in EP/TEA/f-MWNTs (weight ratio 1/0.1/0.01) system was higher than the neat EP/TEA (weight ratio 1/0.1) system, while the curing heat in EP/TEA/p-MWNTs (weight ratio 1/0.1/0.01) was lower than the neat system. When the content of f-MWNTs was increased to 2 phr (weight ratio of 1/0.1/0.02), the curing heat became lower than that of the neat EP/TEA system, which was the result of the higher viscosity of the EP/f-MWNTs/TEA system. Since the curing heat indicated the curing degree of the system generally, the addition of the f-MWNTs was thought to increase the curing degree of the epoxy matrix at a relatively low content.