十六烷基三甲基溴化铵修饰的羧基化单壁碳纳米管的细胞毒性

采用十六烷基三甲基溴化铵（CTAB）作为表面活性剂修饰羧基化的单壁碳纳米管（SWNT-COOH/CTAB）,并对原始单壁碳纳米管（SWNTs）与羧基化修饰的单壁碳纳米管（SWNT-COOH）进行材料学特征比较。通过细胞活力和细胞凋亡实验对SWNTs、SWNT-COOH和SWNT-COOH/CTAB的细胞毒性进行比较。结果表明,羧基化修饰的单壁碳纳米管比原始单壁碳纳米管的毒性小,单壁碳纳米管经羧基化后其毒性降低;浓度及时间曲线显示SWNT-COOH/CTAB的毒性与表面活性剂CTAB相关,CTAB和 SWNT-COOH/CTAB的细胞毒性在低浓度范围内（0.5-25μg/mL）是可接受的。十六烷基三甲基溴化铵修饰的羧基化单壁碳纳米管在低浓度范围（0.5-25μg/mL）内可以较安全地用于生物医学领域。     

纳米羟基硅酸镁的原位表面修饰和二次表面修饰

对纳米羟基硅酸镁粉体分别采用原位表面修饰和二次表面修饰进行表面化学修饰,在其表面引入众多有机短链和有机长链,使纳米羟基硅酸镁粉体在有机介质中有较好的相容性和分散稳定性。利用透射电子显微镜和傅立叶红外光谱仪分别表征了表面修饰改性前后纳米粉体的表面形貌和红外吸收光谱。结果表明:修饰剂与粉体表面发生化学吸附。未经表面修饰处理的纳米粉体呈纳米颗粒和纳米管/棒的团聚体;经过原位表面修饰处理的纳米粉体的分散性得到很大改善,呈局部分散的表面形貌;经过原位表面修饰和二次表面修饰,纳米羟基硅酸镁粉体在有机溶剂中得到有效分散。     

多孔镁表面生物活性β-TCP涂层的制备及其细胞相容性研究

采用化学沉积法在镁支架表面制备生物活性的β-TcP(磷酸三钙陶瓷)涂层,利用X射线衍射,扫描电子显微镜研究β-TCP涂层的相结构和表面形貌.并对表面改性的镁支架与类成骨细胞UMR106的体外生物相容性进行了详细研究.结果表明,表面改性后的镁支架浸提液细胞毒性为1级,即无细胞毒性;材料浸提液无细胞DNA毒性,对细胞周期无改变,也无异倍体细胞出现.实验结果证明,表面改性后的多孔镁具有良好的细胞相容性,是一种很有前景的新型骨组织工程支架材料.     

单链DNA/表面活性剂与单壁碳纳米管的亲合力及荧光检测性能(英文)

研制一种基于单链DNA与单壁碳纳米管荧光变化的新型荧光探针用于表面活性剂物质的检测方法。考察了温度对探针稳定性的影响,通过观察实时荧光光谱变化来评估单壁碳纳米管与5种常见表面活性剂物质的亲和性,观察镁离子及pH对探针检测表面活性物质的影响,通过观察荧光发射光谱变化来考察加入不同浓度表面活性物质曲拉通X-100后荧光探针的荧光恢复情况。结果表明,在5~80°C的温度范围内,探针十分稳定;单壁碳纳米管与5种常见表面活性物质的亲和力由强至弱依次为曲拉通X-100、十二烷基苯磺酸钠、吐温-20、吐温-80、十二烷硫酸钠;荧光探针检测的最佳Mg2+浓度为10mmol/L,pH为7.4;当加入不同浓度的表面活性剂物质曲拉通X-100时,探针体系的荧光逐渐得到恢复。     

金纳米颗粒的自组装修饰及其生物学效应

为了探究金纳米颗粒(Au NP)s的表面自组装亲疏水性修饰及其生物学效应,通过自组装技术制备SH-(CH2)11OH和SH-(CH2)11CH3不同配比修饰的Au NPs,并用透射电子显微镜(TEM)、纳米粒度仪和傅里叶变换红外光谱(FT-IR)检测修饰后的表面形貌与结构特征。用体视显微镜观察Au NPs修饰后对斑马鱼胚胎/幼鱼表型的影响。用MMT、NO含量试剂盒、总抗氧化能力(T-AOC)试剂盒检测Au NPs修饰后对人脐静脉内皮细胞(HUVECs)毒性和功能指标的影响。利用电感耦合等离子体发射光谱和TEM检测Au NPs修饰后被HUVECs摄入情况。结果表明,用SH-(CH2)11OH修饰比用SH-(CH2)11CH3修饰的Au NPs毒性大,当修饰Au NPs的SH-(CH2)11OH和SH-(CH2)11CH3配比为50:50时毒性最小。     

碳纳米管承载氧化锆纳米粒子的研究

在液相沉淀法制备超细粉的工艺中引入碳纳米管，作为ZrO2的承载体。TEM观察发现添加表面活性剂可以实现碳纳米管对ZrO2的有效承载，未加表面活性剂出现了两者的分离。液相中Zeta电位分布的变化表明表面活性剂的添加有利于碳纳米管在水相中的分散，对工艺机理的研究揭示了表面活性剂其疏水基吸附在碳纳米管表面，而其亲水基与ZrO2水合物结合，在碳纳米管承载氧化锆纳米粒子复合材料制备中起到了桥接作用。     

多壁碳纳米管/氧化铁复合粉体的制备

利用混合酸对催化裂解法制备的碳纳米管进行纯化,然后先后用氨水和柠檬酸对纯化后的多壁碳纳米管进行修饰,最后利用共沉淀法制备碳纳米管氧化铁前驱体,并于450℃下热处理2 h.通过X射线衍射仪、扫描电镜和透射电镜表征了复合粉体的结构和形貌.光谱结果表明:经过混合酸纯化后,碳纳米管表面拥有丰富的羟基和羧基等官能团,而且能够在纯化后的多壁碳纳米管表面引入氨基和柠檬酸分子.电子显微图像显示碳纳米管表面被α-Fe2O3纳米颗粒和纳米棒修饰.     

碳纳米管增强银复合材料的导热性(英文)

通过分子水平层级混合制备了碳纳米管增强银基复合材料。研究了碳纳米管的类型(单壁/多壁)及功能化模式(共价键/非共价键)对银复合材料导热性的影响。XRD及EDS结果表明,复合材料中存在银与碳。高分辨率扫描电镜和透射电镜结果表明碳纳米管均匀地嵌在银基体中。利用拉曼光谱和FTIR研究了共价键功能化对多壁碳纳米管的影响。共价键功能化后,碳纳米管中引入了功能团且保持结构完整。利用激光闪光技术以及有效介质理论研究了复合材料的导热性。实验结果表明:加入共价功能化的单壁和多壁纳米碳管后,材料的导热性降低。但加入非共价键功能化的多壁碳纳米管后,复合材料的有效导热性增强,这与不考虑界面热阻时的有效介质理论预测结果一致。     

苯甲酸修饰碳纳米管的制备及其负载Co(OH)2的电化学电容性能

以苯甲酸功能化碳纳米管为基底,制备Co(OH)2/苯甲酸化功能化碳纳米管复合材料.苯甲酸官能团在合成过程中发挥了双重作用:既明显改善碳纳米管在去离子水中的分散性,又使得碳纳米管管壁与Co2+表面结合能力大大加强.透射电子显微镜、扫描电子显微镜以及X射线衍射等表征表明,Co(OH)2在碳纳米管上的分散性得到很大改善;电化学实验结果表明,该复合材料拥有优良的电容行为,其比容量在电流密度为5 mA/cm2时达到322.3 F/g,较Co(OH)2/纯化碳纳米管复合材料以及纯Co(OH)2电极高出100 F/g左右.实验结果表明,以苯甲酸功能化碳纳米管为基底可以进一步有效提高Co(OH)2的利用率.     

化学镀铜法制备 Cu-CNTs 复合粉体的预分散工艺研究

利用离子型表面活性剂(十二烷基苯磺酸钠)和非离子型表面活性剂(TX10)对碳纳米管进行了预分散,不通过活化、敏化处理,直接采用化学镀方法在CNTs表面包覆金属铜。对比了两种分散剂的分散效果,研究了镀液pH值、温度及施镀时间对包覆效果的影响。结果表明:十二烷基苯磺酸钠的分散效果更好,更有利于镀铜;在镀液温度为30℃,pH为11~12的条件下施镀30 min,可以获得被铜完全包覆的碳纳米管。     

Synthesis of aligned carbon nanotube with straight-chained alkanes by nebulization method

Aligned carbon nanotubes (CNTs) were synthesized by nebulized spray pyrolysis of solutions of organometallics in carbon precursor solvents. Four types of straight-chained alkanes including n-pentane, n-hexane, n-heptane and n-octane were used as precursor solvents for synthesis of aligned CNTs. The results from scanning electron microscopy, transmission electron microscopy and Raman spectroscopy show that the CNTs obtained from them have different diameters and degrees of graphitization. It is found that the n-heptane is the most suitable for the growth of aligned CNTs with high quality and yield. The thermodynamic properties of precursory carbon sources such as boiling point and formation enthalpy are considered to play a decisive role in the synthesis of CNTs. It will be very helpful for the controllable preparation of aligned CNTs at relatively low cost.     

钟罩浸块铸造法制备的CNTs/AZ31镁基复合材料的力学性能

将Al粉、Zn粉、碳纳米管(CNTs)混合料按照质量比为3:1:X(X=0,0.5,1.0,1.5)压块,并用钟罩压入法将这些预先制备的压块加入到合金熔体中制备AZ31/CNTs复合材料。测试该复合材料的力学性能,利用扫描电子显微镜(SEM)、能谱分析仪(EDS)、X射线衍射仪和光学显微镜对AZ31/CNTs复合材料的金相试样、断口形貌进行表征和分析。结果表明:钟罩压块法可以有效地将碳纳米管分散到镁合金熔体中;CNTs对AZ31镁合金的力学性能有较强的增强效果,与本研究中的铸造AZ31合金相比,AZ31/CNTs复合材料的最大抗拉强度和伸长率分别提高41.3%和119.4%,弹性模量和显微硬度分别提高67.8%和66.9%;CNTs对AZ31镁合金基体晶粒的细化作用显著,与镁基体界面结合较好;复合材料试样断口形貌由韧窝和撕裂棱组成,呈现准解理断裂特征。     

Electrochemical production of Sn-filled carbon nanotubes in molten salts

Sn-filled carbon nanotubes(CNTs) were prepared in situ by electrolysis of graphite in molten LiCl/SnCl2 mixtures. Transmission electron microscopy(TEM) investigation shows that the as-made products contain abun-dance of carbon nanotubes and most of them are filled with metal nanoparticles or nanorods. Some nanotubes are e-ven inserted with long continuous nanowires more than several micrometers in length. Selected area electron diffrac-tion(SAED) patterns and energy dispersive X-ray spectroscopy(EDS) of the filled nanotubes confirm the presence of Sn inside the nanotubes. The encapsulated Sn was further identified as β-Sn with tetragonal structure. Based on the experimental results, a possible growth mechanism of the Sn-filled nanotubes was also discussed.     

Polypyrrole/MWNT nanocomposites synthesized through interfacial polymerization

Polypyrrole/carbon nanotubes (CNTs) composites were synthesized by dispersion of organically modified multiwall carbon nanotubes during an interfacial polymerization of pyrrole. During the polymerization, the carbon nanotubes are entrapped by the polymer chains and the nanocomposite is formed in the interphase between two immiscible solvents. The method favours a better dispersion of the nanotubes in the polypyrrole offering enhanced electrical properties. The characterisation of the composite material has been established by XRD, TGA analysis and electron microscopy techniques.     

碳纳米管表面处理技术的研究

对催化裂解法制备的碳纳米管（CNTs)分别进行了酸处理，高温石墨化及酸处理结合高温石墨化的综合处理。利用透射电镜，拉曼光谱仪，红外光谱仪等手段对处理前后的CNTs进行了分析。结果表明，石墨化和酸煮对CNTs表面的去除非晶碳，提高晶态化程度的作用都具有明显的效果，而2种方法相结合则对碳纳米管晶化程度的提高作用效果更加显著。     

One-step synthesis of carbon nanotubes with Ni nanoparticles as a catalyst by the microwave-assisted polyol method

Carbon nanotubes (CNTs) were firstly synthesized by the microwave-assisted polyol method and magnetic Ni nanoparticles were employed as a catalyst in the process. The structures, morphologies and magnetic properties of the as-synthesized samples were investigated by using X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM), respectively. Our results indicated that CNTs can be synthesized after the observation of a small electric spark with Ni particles used as a catalyst. TEM showed that the length of the hollow carbon nanotubes was of the order of micron. VSM demonstrated that Ni/CNTs composite was ferromagnetic characteristic with hysteretic behavior at room temperature.     

Carbon nanotube/polyaniline core-shell nanowires prepared by in situ inverse microemulsion

By the in situ inverse microemulsion, we prepared multi-walled carbon nanotubes/polyaniline composites (MWNTs/PANI). Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) showed that the nanotubes were coated with a PANI layer. Fourier transform infrared (FT-IR) spectra suggested that the π-bonded surface of the carbon nanotubes (CNTs) interact strongly with the conjugated structure of the PANI shell layer. The thermal stability and electrical conductivity of the MWNTs/PANI composites were examined by thermogravimetric analysis (TGA) and conventional four-probe method. In comparison with the pure PANI, the decomposition temperature of the MWNTs/PANI (1 wt% MWNTs) composites increased from 360 to 400 °C and the electrical conductivity of MWNTs/PANI (1 wt% MWNTs) composites was increased by one order of magnitude.     

通过喷涂的方法使用单壁碳纳米管制备柔性透明导电薄膜

采用喷涂的方法将分散剂SDS和去离子水分散好的单壁碳纳米管（SWCNTs）喷到基底为聚对苯二甲酸乙二酯PET上制备柔性透明导电薄膜（TCFs）,这种柔性透明导电薄膜具有很高的柔韧性和透明度,当然这种柔性透明导电薄膜（TCFs）的面电阻和透明度与单壁碳纳米（SWCNTs）的长度、直径、缺陷、手征、纯度及分散度等相关,而且分散程度对于柔性透明导电薄膜（TCFs）的特性有很大的影响。     

Aligned multi-walled carbon nanotubes on different substrates by floating catalyst chemical vapor deposition: Critical effects of buffer layer

Aligned multi-walled carbon nanotubes (MWCNTs) were synthesized by floating catalyst chemical vapor deposition on two types of substrates, with emphasis on the effects of an aluminum buffer layer. It has been revealed that the presence of the aluminum buffer layer on insulating/semiconducting silicon oxide/silicon wafer resulted in a higher growth rate, narrower diameter distribution, neater morphology and improved crystalline quality of MWCNTs. When an aluminum buffer layer is deposited on electrically conductive carbon paper, high yield CNTs can be achieved while no CNTs can be observed without this buffer layer. Morphology, structure and chemical states of the products were examined by field-emission scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The generation of alumina from the aluminum buffer layer is thought to play an important role in promoting the nanotube growth. Detailed growth mechanism of MWCNTs was also discussed.     

Deposition rate and morphology of carbon nanotubes at different positions in a CVD reactor

Carbon nanotubes (CNTs) were synthesized through the catalytic decomposition of a ferrocene-xylene mixture in a horizontal chemical va- por deposition reactor. The deposition rate of CNTs along the axial direction was measured. The morphology of CNTs was observed by scan- ning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that the deposition rate of CNTs along the axial direction first increased and later decreased, the position achieving the maximum deposition rate was influenced by the operating conditions. The morphologies of CNTs also changed along the axial direction.