纳米金/碳纳米管复合材料的研究进展

综述了制备纳米金/碳纳米管复合材料的基本原理,详细讨论了这种复合材料的具体制备方法,如自组装法、化学镀法和浸渍法,并对其基本的光、电、催化性质和应用作了简要的介绍,同时展望了这种复合材料的应用前景.     

碳纳米管/聚乙烯咪唑纳米复合材料的制备与表征

采用化学改性手段制备了一类新型的碳纳米管／聚乙烯咪唑(CNTs／PVI)纳米复合材料。并通过红外光谱、扫描电镜、透射电镜和X射线衍射等手段表征CNTs／PVI产物。有机杂环聚合物引入碳纳米管材料体系以后,会显著改善碳纳米管在有机溶剂中的分散均匀性和可加工性,并将碳纳米管具有的优异力学、热稳定性能和杂环聚合物具有的优良溶解性等结合起来,得到一种新型的综合性能优异的光电功能材料。     

铜/碳纳米管复合材料的制备与表征

报道了在多壁碳纳米管(MWNTS)表面修饰聚丙烯酸(分子量为 500~1000)作为亲水层,改善纳米管在水溶液中的溶解性,减少碳管自身团聚,顺利实现碳纳米管表面化学镀铜。同时也考察了温度、时间、搅拌速度等因素对镀层的影响,确定中性条件在碳纳米管表面镀铜的最佳条件。     

碳纳米管/聚苯乙烯复合材料的制备及流变行为

强酸氧化法对多壁碳纳米管(CNTs)进行了纯化,用FT-IR和TEM对CNTs的纯化效果和形态进行了表征。制备了CNTs/PS纳米复合材料,在ARES-RFS型旋转流变仪上对复合材料的动态流变行为进行了研究。结果表明,与纯聚合物相比,CNTs的加入使复合材料熔体呈现出由类液体粘弹行为向类固体粘弹行为的转变,表现为在低剪切速率作用下,纳米复合材料的黏度和储存模量对频率的依赖性变小。     

聚偏氟乙烯/碳纳米管纳米复合材料的制备和表征

采用超声波分散法制备了聚偏氟乙烯(PVDF)/多壁碳纳米管(MWCNT)复合材料。利用扫描电子显微镜、差示扫描量热法和傅立叶变换红外光谱等方法研究了复合材料的形态,考察了MWCNT用量对复合材料结晶行为和力学性能的影响。结果表明,通过超声处理,PVDF和MWCNTs之间产生了相互作用,复合体以球状的形式存在。MWCNTs的引入导致具有压电性的β相形成和屈服强度的提高。根据实验结果,对PVDF/MWCNT复合球体和β相的形成机理提出了可能的解释。     

聚合物/碳纳米管纳米复合材料研究进展

碳纳米管及其聚合物基纳米复合材料的研究是材料科学领域一个重要的研究方向,本文介绍了近年来碳纳米管的表面改性方法以及聚合物/碳纳米管复合材料的制备方法、力学性能、导电性等方面的研究进展。     

碳纳米管/聚苯胺复合材料的制备及电性能

利用超声波将多壁碳纳米管(CNTs)分散于苯胺盐酸溶液体系中,以过硫酸铵((NH4)2S2O8)为氧化剂,原位聚合法制备碳纳米管/聚苯胺纳米复合材料(CNTs/PANI)。采用扫描电子显微镜(SEM)、傅立叶变换红外光谱(FT-IR)、四探针电导率测试仪对复合材料进行表面观察、结构测定和电性能表征。结果表明,复合材料为核-壳结构,碳纳米管和聚苯胺间存在相互作用,其电导率随碳纳米管含量的增加而增加。     

新型定向碳纳米管/炭复合材料的制备与表征

采用化学气相沉积（CVD）方法制备了厚度超过4mm的定向碳纳米管（ACNTs）阵列，并以此为骨架，利用化学气相渗（CVI）工艺制备了新型的定向碳纳米管／炭（ACNT／C）复合材料。利用SEM、PLM、XRD、TGA和Raman光谱对ACNT／C复合材料进行了表征。结果表明：ACNT／C复合材料中的热解炭主要为类粗糙层（RL）结构，而在相同工艺条件下制备的炭／炭（C／C）复合材料的热解炭为典型的光滑层（SL）结构。ACNT／C复合材料晶化程度明显优于相同工艺条件下的C／C复合材料。同时，ACNT／C复合材料在空气中的热失重转变温度比相同工艺条件下制备的C／C复合材料提高了约50℃左右。     

壳聚糖/硫化汞纳米复合材料制备与表征

用Hg(NO3)2和TAA为原料,以壳聚糖为模板于室温条件下在水溶液中合成了粒度分布均匀、分散性好的HgS纳米粒子。产物为球形的多晶粒子,平均粒径为20nm,属于立方闪锌矿结构。合成的纳米晶具有良好的光学性能,与体相材料相比表现出明显的量子尺寸效应。用XRD、TEM-SAED、HRTEM、Uv-vis、FT-IR和PL等实验手段对产物进行了分析和表征,并对HgS纳米晶的形成机理进行了初步探讨。     

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。     

多元醇方法制备SnO2包覆碳纳米管复合材料

本文采用SnC2O4.2H2O为Sn源和乙二醇(ethylene glycol,EG)为反应介质的多元醇法,制备得到SnO2包覆多壁碳纳米管复合材料(SnO2/MWNTs),其中SnO2是通过EG中溶解的O2氧化Sn2+反应生成的.没有加入MWNTs的情况下,SnC2O4.2H2O的水解反应生成Sn6O4(OH)4,SnC2O4.2H2O与EG之间的聚合反应生成聚羟基乙酸锡,由于水解反应降低了EG中Sn2+的浓度,使得聚羟基乙酸锡产量较低.加入MWNTs后,仅有少量聚羟基乙酸锡生成,且没有Sn6O4(OH)4生成,主要产物为包覆在MWNTs表面的SnO2.这是由于SnO2在EG中的溶解度极低,随O2氧化Sn2+反应进行,EG中的Sn2+浓度不断降低,Sn6O4(OH)4的溶解结晶平衡不断向溶解的方向进行,并最终转化为SnO2.以上对多元醇法制备SnO2/MWNTs合成机理的理解,将有助于采用类似的方法设计合理条件制备得到其他种类金属氧化物包覆碳纳米管的复合材料.     

碳纳米管/导电聚苯胺纳米复合纤维的合成与表征

为实现碳纳米管在树脂内形成一体化导电网络，从而制备出透明导电性能最优的有机透明导电涂层，必须把导电性的碳纳米管纤维在树脂内有效地组装成一体化导电结构网络。本文报道运用在树脂内可以自组装的导电苯胺来实现碳纳米管纤维自组装的方法．合成出了导电聚苯胺纳米薄膜均匀包覆的碳纳米管/导电聚苯胺纳米复合纤维．并运用透射电镜、傅立叶红外光谱以及四探针法表面电阻测试仪对合成出的具有精细微观结构的纳米复合纤维进行了表征．发现合成出了理想的碳纳米管/导电聚苯胺纳米复合纤维，并且其导电性较碳纳米管和导电聚苯胺自身都有大幅度的提高。这种特殊结构的纳米复合纤维的制备为组装高性能的聚合物基透明导电涂层奠定了坚实基础，而且这种自组装方法为各种纳米纤维的组装提供了可能。     

化学气相沉积法制备多壁碳纳米管

以带程序升温装置的管式电阻炉为实验装置,采用化学气相沉积法,在一定的工艺条件下裂解二茂铁与双鸭山精煤的混合物制备出多壁碳纳米管.采用透射电镜、Raman光谱以及X射线衍射技术对碳纳米管产物进行表征,同时研究了碳纳米管的生长机理.     

Synthesis of multi-walled carbon nanotube/silver nanocomposite powders by chemical reduction in aqueous solution

Carbon nanotube (CNT)/silver nanocomposite powders with different volume fractions of CNTs 2.5, 5 and 10?vol.% were prepared by chemical reduction in solution. Multi-walled CNTs underwent surface modifications for functionalisations by acid treatments. The acid-treated CNTs were investigated by FT-IR and X-ray photoelectron spectroscopy. The spectroscopic investigations of the acid-functionalised CNTs detected that several kinds of functional groups attached with the graphene structure as well as produced short and de-caped CNTs. Acidic stannous chloride solution was used to sensitise the surface of the functionalised CNTs. Silver was deposited on the surface of sensitised CNTs with chemical reduction reaction of alkaline silver nitrate solution by formaldehyde at room temperature and pH?～?9. The morphology of the produced CNT/silver nanocomposite powder was investigated by high-resolution SEM and TEM. It was observed that the produced CNT/silver nanocomposite powders have decorated type of spherical silver particle size 2–5?nm deposited on the surface of CNTs as well as the CNTs were implanted in large spherical silver nanoparticles of particle size ～200?nm. The chemical analysis of the produced powder indicates that some oxygen content is included in the prepared powders which can be reduced by heat treatment at temperatures between 300°C and 400°C under hydrogen atmosphere.     

碳纳米管的催化裂解聚苯乙烯法的制备及其表征研究

利用流动催化裂解法以聚苯乙烯为碳源,二茂铁为催化剂前躯体制备出了碳纳米管.用扫描电子显微镜,透射电子显微镜,拉曼光谱和X射线衍射对碳纳米管的结构进行了表征.再者,通过导入噻吩,合成了一种有很多细碳纳米管分支的碳纳米管.该制备过程工艺简单,碳源价格低廉.利用这个方法,通过控制条件,可得到不同结构的碳纳米管.     

Synthesis, characterization, and photocatalytic activities of titanate nanotubes surface-decorated by zinc oxide nanoparticles

Nanoscaled zinc oxide (ZnO) particles with different amounts are coated on titanate nanotubes (TNTs) by a facile chemical method at room temperature. The characterizations of XPS, TEM, XRD and UV-vis spectra confirm that pure hexagonal wurtzite ZnO nanoparticles with an average size of about 9nm are distributed on the surfaces of TNTs evenly and attached strongly. The photocatalytic activities of the ZnO-TNTs nanocomposite are superior to those of P25, ZnO, TNTs and ZnO-anatase TiO2 (TNP) nanocomposite in the oxidation of rhodamine B under UV light irradiation. A comparison of the photocatalytic activities between different catalysts is discussed. Furthermore, we also find that the ZnO-TNT nanocomposite shows very favorable recycle use potential, because they have a high sedimentation rate and their photocatalytic activity is only slightly decreased even after five times of repeated uses.     

Titania-carbon nanotubes nanocomposite coating on Mg alloy: microstructural characterisation and mechanical properties

Atmospheric plasma spraying was carried out to deposit a bilayered NiCrAlY/nTiO₂-CNT composite coating. Initially, NiCrAlY, as an under-layer with a thickness of around 100?µm, was deposited. Afterwards, nanostructured TiO₂ (nTiO₂), as an over-layer with a thickness of 135?μm, was deposited with and without the incorporation of carbon nanotubes (CNTs) on the Mg alloy surface. In contrast to NiCrAlY and NiCrAlY/nTiO₂, the NiCrAlY/nTiO₂-CNT nanocomposite coating displayed a higher bonding strength. The wear behaviour of the coatings was examined by the pin-on-disc test and the results revealed that the incorporation of CNTs into the nTiO₂ coating considerably enhanced the tribological behaviour of Mg alloy due to the CNT’s bridging mechanism.     

环己烷浮游催化法在碳纤维表面生长碳纳米管

以环己烷为碳源、二茂铁为催化剂前躯,采用浮游催化法成功的在碳纤维表面生长了碳纳米管(CNT),制备了多尺度杂化材料CNTs/CF。实验重点考察了反应温度、二茂铁浓度、载气等参数对CNT在纤维表面生长的影响,通过扫描电镜(SEM)、投射电镜(TEM)研究了CNTs/CF的形貌及产物CNT的微观结构。当固定反应温度为820℃、二茂铁-环己烷浓度为2g/100mL时,随着氢气在载气中含量在0～100%范围内变化,产物CNT直径亦有86nm降低至39nm。通过单丝拉伸测试发现,相比初始碳纤维,不同长度的CNTs/CF单纤维强度下降幅度均在10%以内。     

A biosensor based on Coriolopsis gallica laccase immobilized on nitrogen-doped multiwalled carbon nanotubes and graphene oxide for polyphenol detection

Abstract

The use of nanomaterials allows the design of ultrasensitive biosensors with advantages in the detection of organic molecules. Catechol and catechin are molecules that occur naturally in fruits, and their presence in products like dyes and wines affects quality standards. In this study, catechol and catechin were measured at the nanoscale by means of cyclic voltammetry. The oxidation of Coriolopsis gallica laccase immobilized on nitrogen-doped multiwalled carbon nanotubes (Lac/CN_x-MWCNT) and on graphene oxide (Lac/GO) was used to measure the concentrations of catechol and catechin. Nitrogen-doped multiwalled carbon nanotubes (CN_x-MWCNT) were synthesized by spray pyrolysis and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and x-ray photoelectron spectroscopy (XPS). Covalently bonded hybrids with laccase (Lac/CN_x-MWCNT and Lac/GO) were generated. Catalytic activity of free enzymes determined with syringaldazine yielded 14 584 UmL^?1. With Lac/CN_x-MWCNT at concentrations of 6.4 mmol L^?1 activity was 9326 U mL^?1, while enzyme activity measured with Lac/GO at concentration of 6.4 mmol L^?1 was 9 234 U mL^?1. The Lac/CN_x-MWCNT hybrid showed higher stability than Lac/GO at different ethyl alcohol concentrations. The Lac/CN_x-MWCNT hybrid can measure concentrations, not previously reported, as low as 1 × 10^?8 mol L^?1 by measuring the electric current responses.     

A biosensor based on Coriolopsis gallica laccase immobilized on nitrogen-doped multiwalled carbon nanotubes and graphene oxide for polyphenol detection

The use of nanomaterials allows the design of ultrasensitive biosensors with advantages in the detection of organic molecules. Catechol and catechin are molecules that occur naturally in fruits, and their presence in products like dyes and wines affects quality standards. In this study, catechol and catechin were measured at the nanoscale by means of cyclic voltammetry. The oxidation of Coriolopsis gallica laccase immobilized on nitrogen-doped multiwalled carbon nanotubes (Lac/CN_x-MWCNT) and on graphene oxide (Lac/GO) was used to measure the concentrations of catechol and catechin. Nitrogen-doped multiwalled carbon nanotubes (CN_x-MWCNT) were synthesized by spray pyrolysis and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and x-ray photoelectron spectroscopy (XPS). Covalently bonded hybrids with laccase (Lac/CN_x-MWCNT and Lac/GO) were generated. Catalytic activity of free enzymes determined with syringaldazine yielded 14 584 UmL⁻¹. With Lac/CN_x-MWCNT at concentrations of 6.4 mmol L⁻¹ activity was 9326 U mL⁻¹, while enzyme activity measured with Lac/GO at concentration of 6.4 mmol L⁻¹ was 9 234 U mL⁻¹. The Lac/CN_x-MWCNT hybrid showed higher stability than Lac/GO at different ethyl alcohol concentrations. The Lac/CN_x-MWCNT hybrid can measure concentrations, not previously reported, as low as 1 × 10⁻⁸ mol L⁻¹ by measuring the electric current responses.