一种新颖结构的煤基定向碳薄膜的制备与表征

以宏源精选煤为原料在微波等离子体条件下制备出一种新颖结构的碳材料,运用场发射扫描电子显微镜、透射电子显微镜和能量色散谱技术对产物进行表征.结果表明：产物形状似莴笋状,外层石墨化程度较好,其最大宽度约为170 nm,长度则为4～5 μm,且呈定向排列.这种新颖结构的纳米碳材料有望在场发射、增强材料等方面显示出巨大的应用潜力.     

α-Fe2O3纳米晶自组装磁性微球的制备及性能研究

以硝酸铁(Fe(NO3)3·9H2O)和氨水(NH3·H2O)为原料,以聚乙烯吡咯烷酮(PVP)为表面活性剂,采用沉淀法制备了α-Fe2O3纳米晶自组装的磁性微球.利用X射线衍射仪和扫描电镜对所得产物进行了表征分析,并在室温下测量其磁学性能.结果表明,所制备的磁性微球由α-Fe2O3纳米晶自组装而成,其粒径大小在0.9～1.3 μm范围.在室温下测试了微球的磁学性能,其剩余磁感应强度为0.31 emu/g,矫顽力为4100 Oe,表现出较强的铁磁性.     

纳米片组装钴铁氧体微球的制备及其性能

采用超声溶剂热法,成功地制备了由片状钴铁氧体(CoFe₂O₄)自组装的微球。采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)对样品的结构和形貌进行了表征。结果表明,所制备的CoFe₂O₄微球为立方晶相结构,其粒径分布在20～30μm之间,是由二维纳米片组装而成。用振动样品磁强计(VSM)和网络矢量分析仪分别对纳米片组装微球样品及自制的CoFe₂O₄粉体的室温磁性和吸波性能进行了测试,结果显示,纳米片组装微球比自制粉体的磁性和微波吸收性能更好,其饱和磁化强度和矫顽力分别达到76.15emu/g和227.89Oe。此外,纳米片组装CoFe₂O₄微球在频率为6000MHz波段附近有一个明显的吸收峰,回损值大于-18dB,并有继续增大的趋势。说明产物的结构和形貌对其磁性和吸波性都有很大影响。     

洋葱状碳纳米颗粒转化为碳纳米管的研究

以热固性酚醛树脂为碳源,以硝酸铁为催化剂前驱体制备洋葱状碳纳米颗粒。采用酸化方法使洋葱状纳米颗粒变成不稳定的球冠状态,在高温下使球冠进行重新组装,转化为形状不规则的碳纳米管,实现了材料转化。并详细分析了洋葱状碳纳米颗粒形成与转化为碳纳米管的机理。     

空气气氛中碳纳米管抗氧化性能研究

以乙炔为原料气,采用Ni粉为催化剂,在923K下,由化学气相沉积法(CVD)制得了碳纳米管。通过微波辅助硝酸溶解除去炭材料中的Ni,并通过热重分析确定了纳米碳管在空气中的氧化温度,同时,通过空气氧化法对所获得的碳纳米管抗氧化性能进行研究。热重分析结果表明,微波辅助硝酸溶解可以明显除去炭材料中的催化剂Ni。扫描电镜测试结果表明,850K左右可以使碳纳米管完全氧化。空气氧化结果表明,本实验中CVD法合成的碳纳米管抗氧化性能低于碳颗粒。     

微波法制多孔石墨烯及对亚甲基蓝的吸附性能

以改进的Hummers法合成的氧化石墨烯为自组装原料,通过微波加热的方式制备三维多孔石墨烯材料.并采用场发射扫描电子显微镜、傅立叶红外光谱仪、X射线衍射仪对石墨、氧化石墨烯、三维多孔石墨的微观形貌和内部结构进行表征分析.以亚甲基蓝为吸附质、三维多孔石墨烯为吸附剂,研究其吸附性能.结果表明,三维多孔石墨烯材料的最大吸附量...     

以碳球为模板合成氧化铈纳米空心球

以直径约为300nm的碳球为模板,通过无机物前驱体颗粒的自组装制备出CeO2/碳球复合物,煅烧去除碳球模板后,得到CeO2纳米空心球.借助透射电子显微镜、选区电子衍射、场发射扫描电子显微镜、X射线衍射、X射线光电子能谱和热重分析仪等测试手段对复合物的形貌和结构进行了表征.结果表明:产物空心球由面心立方相CeO2颗粒构成...     

碳纳米管-草酸锌/聚氨酯泡沫的制备与性能

采用溶胶-凝胶法合成了碳纳米管-草酸锌粉体(CNT-ZnOD),扫描电子显微镜照片表明,其含有三种典型的结构:ZnOD包覆在CNT表面上形成的"核/壳"结构,针叶状结构的ZnOD以及由ZnOD自组装形成的类金字塔结构。通过浸渍法制备了阻燃软质聚氨酯/CNT-ZnOD泡沫材料;通过热分析仪和锥形量热仪等对材料的热稳定性和燃烧性能进行了研究。热分析结果表明,CNT-ZnOD有利于提高软质聚氨酯泡沫在280℃以上的热稳定性;锥形量热仪结果表明,CNT-ZnOD能够同时降低泡沫材料的热释放速率和总烟释放量。     

微波与碳基催化剂协同促进果糖制5-羟甲基糠醛

生物质转化为高附加值的化学品是替代石化产品的有效途径,微波与催化剂的协同作用有助于提升糖类的转化效率。碳材料具有良好的化学稳定性和介电性,是微波反应过程中理想的催化剂载体和吸波剂。为了探究碳基催化剂对微波场的响应能力,本文以4种碳材料为载体应用于果糖转化过程,包括碳纳米管（CNT）、碳纳米纤维（CNF）、炭黑（CB）和活性炭（AC）。以果糖转化率和5-羟甲基糠醛（5-HMF）收率为评价指标,对比不同催化剂在常规和微波加热条件下的催化性能,探究微波与不同载体的耦合作用对反应的强化效果。在微波场中测量不同碳材料悬浮液的温度曲线,评价碳基催化剂在微波场中的加热能力。通过表征样品结构和介电参数,解释载体与微波间耦合作用差异的原因。结果表明,碳基催化剂的微波诱导热效应可以有效提升反应转化率和收率,拥有高损耗角正切值和电导率的催化剂把微波能转化为热量的能力较强,更有助于将微波能量传递至反应表面。高比表面积、高长径比、低密度和高石墨化度的碳基催化剂也有利于产生微波热效应。另外,由于显著的微波热效应,碳纳米管基催化剂CNT-SA在4类催化剂中催化性能最优,以110℃微波辐射10min,5-HMF收率可达96.30%,且催化剂具有良好的循环使用性能。     

α-Fe_2O_3空心微米球的制备及储锂性能研究

以异丙醇-丙三醇为反应溶剂,利用溶剂热法制备出α-Fe_2O_3空心微米球。采用X-射线粉末衍射光谱(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)对产物的形貌和结构进行表征,结果表明,产物是由平均厚度约为5 nm的纳米片自组装而成的α-Fe_2O_3空心球。将产物组装为锂离子电池,并对其储锂性能进行研究,实验结果表明,α-Fe_2O_3空心微米球具有较大的充放电容量和良好的循环稳定性。本研究为发展高容量的锂离子电池负极材料提供了可行的途径。     

Facile approach to prepare multi-walled carbon nanotubes/graphene nanoplatelets hybrid materials

A facile approach was developed to prepare multi-walled carbon nanotubes/graphene nanoplatelets hybrid materials through covalent bond formation. First, poly(acryloyl chloride) was grafted onto oxidized multi-walled carbon nanotubes through the reaction between the acyl chloride groups of poly and the hydroxyl groups of oxidized multi-walled carbon nanotubes. Second, the remaining acyl chloride groups of poly were allowed to react with the hydroxyl groups of hydroxylated graphene nanoplatelets. Scanning electron microscopy and transmission electron microscopy data showed that the multi-walled carbon nanotubes and graphene nanoplatelets were effectively connected with each other. And Fourier transform infrared spectroscopy data indicated the formation of covalent bonds between carbon nanotubes and graphene nanoplatelets. Conformational changes were monitored by Raman spectroscopy. This novel kind of carbon hybrid materials may have the potential application in a wide field, especially in increasing the toughness and strength of the matrix resin.     

Electrochemical properties of double wall carbon nanotube electrodes

Electrochemical properties of double wall carbon nanotubes (DWNT) were assessed and compared to their single wall (SWNT) counterparts. The double and single wall carbon nanotube materials were characterized by Raman spectroscopy, scanning and transmission electron microscopy and electrochemistry. The electrochemical behavior of DWNT film electrodes was characterized by using cyclic voltammetry of ferricyanide and NADH. It is shown that while both DWNT and SWNT were significantly functionalized with oxygen containing groups, double wall carbon nanotube film electrodes show a fast electron transfer and substantial decrease of overpotential of NADH when compared to the same way treated single wall carbon nanotubes. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

碳纳米管改性填料对氟碳涂料性能的影响

采用混合酸和表面活性剂对碳纳米管表面进行改性处理,利用改性碳纳米管与不同的填料构造复合填料,并与FEVE氟碳树脂合成了碳纳米管改性复合氟碳材料,并将其涂覆在陶瓷基底上形成氟碳涂层。采用红外光谱（FTIR）对表面改性后的碳纳米管进行了表征分析,用扫描电镜（SEM）、接触角测量仪等仪器观察和测试了纳米复合氟碳涂层表面的微观结构及疏水性。研究结果表明：用混合酸和表面活性剂改性碳纳米管,碳纳米管的缠绕、团聚现象得到明显的改善,提高了其在氟碳树脂体系中的分散性能;当改性碳纳米管的量为0.75 g时,涂层的憎水性能较好。     

A novel method to graft carbon nanotube onto carbon fiber by the use of a binder

A novel method is developed for grafting multiwall carbon nanotubes (MWNTs) onto the surface of polyacrylonitrile‐based high strength (T300GB) carbon fiber. Functionalized MWNTs were well dispersed in the PVA solution and the carbon fiber was dip‐coated in this solution. After heat treatment of the coated carbon fiber under a nitrogen atmosphere, MWNTs with carboxyl groups were grafted onto the functionalized carbon fiber via chemical interaction. The resulting materials were characterized by Fourier transform infrared (FTIR), X‐ray photoelectron spectroscopy (XPS), Field emission scanning electron microscopy (FESEM), Raman spectrum and mechanical testing. FESEM observations revealed uniform coverage of carbon nanotubes on carbon fiber. The carbon fiber grafted with MWNTs improved the tensile strength by 12% with respect to the pristine carbon fiber. These results are supportive of good interfacial bonding between the carbon nanotubes (CNTs) and carbon fiber. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

碳纳米管改性处理的研究

用不同的处理方法，对碳纳米管进行改性处理，结合碳纳米管的理论估算，通过BET法评价不同处理方法的改性效果。实验结果表明碳纳米管经过空气氧化或浓混酸回流处理后，由高倍透射电镜显示，其管长变短。管端端帽开口，从而显著增加了碳纳米管的比表面积和孔容。     

Carbon nanotube‐reinforced polyacrylonitrile nanofibers by vibration‐electrospinning

Carbon nanotubes (CNTs) are thought to be perfect enhancive materials for composites. Multi‐wall carbon nanotubes were directly electrospun into polyacrylonitrile (PAN) nanofibers via both traditional electrospinning and vibration‐electrospinning. The fibers obtained were examined by scanning electron microscopy and X‐ray diffraction. CNTs were aggregated heavily in the fibers obtained by traditional electrospinning while CNTs were well distributed and aligned in PAN fibers obtained by vibration‐electrospinning. Copyright © 2007 Society of Chemical Industry     

掺氮碳纳米管的结构、制备及其催化应用

将氮原子掺入到碳纳米管的晶格中,使碳纳米管表面碱性增强,从而改变了碳纳米管表面的吸附性能;掺杂在碳纳米管晶格中的氮原子的高电子云密度还导致碳纳米管在电子、材料和催化方面具有独特的性能.介绍了掺氮碳纳米管结构特征和制备方法,综述了近年来在催化中的应用.     

单壁碳纳米管的纯化研究

为了获得纯净的单壁碳纳米管,根据催化裂解法制备的单壁碳纳米管中所含杂质的性质和特点,运用综合纯化法,将液相氧化、超声和过滤等相结合对单壁碳纳米管进行纯化。利用透射电子显微镜、热重分析等对单壁碳纳米管进行表征。研究结果表明,使用该纯化流程可以得到一个好的纯化效果。     

Role of Carboxylic Acid-Functionalized MWCNTs in Potentially Biodegradable Poly(Amide–Imide) Nanocomposites Based on N,N′-(Pyromellitoyl)-bis-S-valine: Preparation,Thermal and Morphological Properties

A simple solution-blending process was used to efficiently disperse of carboxyl-modified multiwalled carbon nanotubes into a potentially biodegradable poly(amide–imide) to obtain poly(amide–imide)/carboxyl-modified multiwalled carbon nanotubes bionanocomposites. Carboxyl-modified multiwalled carbon nanotubes were utilized to better dispersion of multiwalled carbon nanotubes into the polymer matrix. The poly(amide–imide)/carboxyl-modified multiwalled carbon nanotube bionanocomposites were prepared with different carboxyl-modified multiwalled carbon nanotube contents (5–15 wt%). The resulting bionanocomposites are characterized by several techniques, powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy analysis, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Adding carboxyl-modified multiwalled carbon nanotube into polymer matrix significantly increased the thermal stability of bionanocomposites due to the increased interfacial interaction between the poly(amide–imide) matrix and carboxyl-modified multiwalled carbon nanotube.     

Hydrogen sulfide sensing properties of multi walled carbon nanotubes

This paper investigates the effect of functional groups on the hydrogen sulfide sensing properties of multi-walled carbon nanotubes using carboxyl and amide groups and Mo and Pt nanoparticles as decorated precursors in gaseous state at working temperature. Carbon nanotubes were synthesized by the CVD process and decorated with the nano particles; provide higher sensitivity for H₂S gas detection. The MWCNTs were characterized by scanning electron microscopy combined with energy dispersive X-ray (SEM/EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), ATR-IR absorption and Fourier transforms infrared (FT-IR) analyses. The MWCNTs were deposited as a thin film layer between prefabricated gold electrodes on alumina surfaces. The sensitivity of carbon nanotubes was measured for different H₂S gas concentrations and at working temperature. The results showed that the measured electrical conductance of the modified carbon nanotubes with functional groups is modulated by charge transfer with P-type semiconducting characteristics and metal decorated carbon nanotubes exhibit better performances compared to functional groups of carboxyl and amide for H₂S gas monitoring at room temperature.