高聚物碳黑复合体化学传感器的研究及其在电子舌中的应用

用碳黑和不导电高聚物复合体制备化学传感器阵列,在检测、量化和识别各种有机气体和液体成分上,最近已受到相当重视.本文介绍了复合体导电机理,制备了两种新型的基于复合体薄膜的化学传感器,并将其应用于实验室开发的电子舌系统,采用阻抗法测量传感器在不同样本液体中的响应,最后用主成分分析法对数据加以识别,初步实验结果表明传感器能够较好的区别酸、甜、苦、咸等味道,且该传感器生命周期长,重复性好,在实时、在线的电子舌系统中具有很好的应用前景.     

基于随机共振的纳米碳管气体传感器的研究

基于气体电晕放电原理,利用纳米碳管独特的物理结构和尖端发射效应,提出了一种新型的纳米碳管离子型气体传感器.采用阳极氧化铝模板法生长的定向纳米碳管阵列所构成的传感器,纳米碳管和电极是一体的,简化了器件结构和工艺.在外加直流电压激励下,纳米碳管顶部形成很强的非均匀电场,在电压相对低的情况下能很容易地电离气体,根据气体的击穿电压和放电电流来实现对单一气体和确定性混合气体的检测.为了提高检测混合气体的灵敏度,创新地在检测回路中引入随机共振发生装置,有效地提高了混合气体浓度检测的范围.实验中还分析了温度、湿度对传感器的影响,对该传感器的性能也作了评价.实验结果表明该传感器具有选择性好、体积小、响应时间快、灵敏度高、稳定性好,室温操作等优点,而且实现方便,操作简单,有较大的实用价值.     

纳米钯基氢传感材料

介绍了纳米Pd基氢传感材料的研究进展.根据传感材料和结构的不同,对Pd/Pd合金膜,Pd/Pd合金纳米线状结构氢传感器的制备和传感性能进行了总结,介绍了Pd-碳管氢传感器的研究成果.使读者较为全面地了解纳米Pd基氢传感材料的现状与研究动向.     

基于多壁碳纳米管负载镍的无酶葡萄糖传感器

文中采用水热法合成负载镍纳米碳管(MWCNTs)复合材料,以Nafion为固定剂将复合材料修饰于玻碳电极的表面制备了一种新型葡萄糖传感器,并用于血清样品中葡萄糖的测定。实验发现,合成在纳米碳管表面的镍为纳米级,并分散均匀。复合材料修饰的电极对葡萄糖响应电流明显大于镍圆盘电极,而且受抗坏血酸和尿酸干扰较小。实验采用安培法测定葡萄糖,线性范围为2×10-6mol/L～1.2×10-3mol/L,检测下限达到了5×10-7mol/L。     

纳米碳管的若干动力学问题

以单壁纳米碳管为例,建立了其分子动力学模型,并对(5,5)和(10,10)扶手椅型纳米碳管与刚性壁的正碰撞过程和简谐纵波传播过程进行了模拟.在此基础上,探讨如何用弹性杆模型来研究纳米碳管的动力学问题。研究表明,弹性杆模型可以描述单壁扶手椅型纳米碳管与刚性壁高速碰撞的动力学行为;对于纵波传播中的色散描述,则需在弹性杆模型中计入纳米碳管微结构引起的非局部弹性效应.     

基于高分子聚合物的柔性传感器研究进展

对基于高分子聚合物的柔性传感器的研究进展进行了概述.从传感器的种类、材料、结构设计、制备工艺、传感原理等多个角度进行分析,并对这些传感器的主要性能(灵敏度、稳定性与重复性、响应时间、迟滞性等)进行评估.重点讨论基于高聚物的柔性传感器在可穿戴设备、柔性驱动以及疾病预防等领域内的应用,总结了当前国内外传感器技术研究所面临的...     

催化裂解简单合成离散的短纳米碳管

研究了一种简单催化裂解生长离散纳米碳管技术.不需要使用基底,于700℃,直接催化裂解Fe(NO3)3·9H2O和无水乙醇的混合溶液,反应30分钟,合成了长度较短的纳米碳管.需要指出的是,该研究与已有的催化裂解无水乙醇生长纳米碳管的区别在于:实验设备简单,工艺参数易于实现,反应温度较低,时间较短,碳源和催化剂间的反应在均相中发生.所得产物的扫描电镜、透射电镜表征显示,合成的纳米碳管呈开口状,相互缠绕程度较小,离散度较大.拉曼光谱检测表明产物为单壁纳米碳管和多壁纳米碳管混合物.文章还对纳米碳管的生长过程进行了探讨.     

纳米碳管气体放电气敏传感器中随机共振现象的研究

在对某些非线性动力学系统中,存在着随机共振现象,它不是通过消除噪声而是利用噪声来达到检测微弱信号的目的,随机共振是非线性动力系统中的普遍现象,它向人们展示了噪声在非线性体系中的积极作用.本文对纳米碳管气体放电气敏传感器中的随机共振现象进行了研究,利用纳米碳管电极作为气敏传感器阳极,在以空气为目标气体的传感器检测系统中观察到二重随机共振现象.提取放电周期脉冲信号,利用高斯白噪声调制放电周期脉冲信号,输出信噪比的仿真结果与实际观察到的二重随机共振现象一致.     

SnO_2纳米结构气体传感器制备与气敏特性研究

由于二氧化锡(SnO_2)稳定的理化性质与优越的导电性能,制备的气体传感器具有灵敏度高、寿命长、稳定性好等特点。利用水热法制备了纳米结构SnO_2材料,进而制作旁热式气体传感器。通过调节氢氧化钠(Na OH)的量,研究不同浓度下纳米结构SnO_2材料的形貌,搭建实验平台,测试不同形貌下敏感材料的灵敏度、选择性、重复性,并分析其敏感机理。     

纳米碳管在HyperChem中的自动生成及其力学性能探究

HyperChem是当今国际上知名的物理化学软件之一。本文作者使用Visual Basic 5．0计算机语言环境，结合HyperChem的Tcl、Hcl语言及DDE功能，开发了HyperChem中自动生成纳米碳管的软件模块。然后，采用HyperChem及其提供的MM 力场，分别对自动生成的纳米碳管及另外一种富勒烯／纳米管的拉伸力学性能进行了尝试性的分子动力学模拟。本文的纳米碳管生成模块及纳米碳管拉伸力学性能探究对HyperChem用户进一步深入研究纳米碳管的性能具有实际的参考价值。     

Surface acoustic wave gas sensors based on polyisobutylene and carbon nanotube composites

Surface acoustic wave (SAW) gas sensors based on polyisobutylene (PIB) and composites (PIB and carbon nanotubes) as sensitive layers were investigated for the detection of octane and toluene (volatile organic compounds) and other atmospheric pollutants (H₂, CO, NO₂ and NH₃) at room temperature. In order to study the effect of nanotubes in the response of SAW sensors, several composites based on PIB with different percentages of multiwalled carbon nanotubes (MWNTs) were tested and compared to the response obtained from PIB SAW sensors. Sensors exhibit high responses and selectivity to volatile organic compounds (VOCs) with fast response and recovery times as well as good repeatability and reproducibility. Experimental results show as small percentages of nanotubes improve the response to octane.     

碳纳米管/PDMS复合材料柔性阵列压力传感器制备与实验

以碳纳米管（CNTs）作为导电填料,聚二甲基硅氧烷（PDMS）为基体材料,采用溶液法制备出CNTs/PDMS导电复合材料。研究了碳纳米管浓度对复合材料的电学特性和压阻特性的影响规律,得到碳纳米管在PDMS中的渗滤区域。通过复合材料的压力灵敏度优化碳纳米管浓度。以制备的复合材料为敏感材料,FPCB工艺加工的柔性基板为电极,设计制备了一种简单结构和工艺的柔性阵列压力传感器。用零电势法设计了阵列电阻读出电路与LabVIEW实现的上位机配合,实现信号读取和显示。最后通过一个应用实例表明,该柔性阵列压力传感器及信号处理系统可以实现压力分布与大小的实时监测,可为柔性阵列压力传感器设计与制备提供参考。     

Rapid-manufacturing of micro-structured devices based on MWCNTs/PP composites by using hot embossing replication process

Carbon nanotubes have attracted the fancy of many scientists since their first discovery in 1991. Their small dimensions, strength and remarkable physical properties make them a very unique material with a whole range of promising applications. The most important application of carbon nanotubes based on their important mechanical properties will be as reinforcements in composite materials, especially nanotube-filled polymer composites are an obvious materials application area. In this work, the micro-structured devices in range of micro meter have been manufactured based on polymer/carbon nanotubes composites by using hot embossing replication process. Firstly, the carbon nanotubes with different loading rate (0.1, 1 and 10 %) have been mixed with polypropylene (PP) in molten state to obtain the composite, the rheological properties of MWCNTs/PP composites with different CNT loading ratios were investigated by means of rheometer with a cone-and-plate geometry, the improvement of dispersion of the CNT particles in polypropylene matrix were observed by scanning electronic microscopy. Afterwards, the obtained composite were granulated in particles and used in hot embossing process to realize the replication of micro structured; in this step, a Al mould with micro-motif on surface obtain by machining with computer numerical control machine tools has been used. Finally, the micro-structured motifs on the mould have been successfully transferred with the details on the MWCNTs/PP substrate under the embossing pressure.     

基于碳纳米管场发射的压力传感器仿真与设计

碳纳米管是场发射阴极的极佳材料.基于碳纳米管和金属铜的复合电镀技术,采用有限元软件对压力传感器的碳纳米管布设进行了有限元仿真,使用模拟退火算法对阳极变形膜的尺寸进行了优化,并设计了实现压力传感器的工艺过程.碳纳米管的管径在不影响电镀质量的情况下可尽量小,选取的长度不影响直立,间距在500 nm时可获得最大电流.阳极膜的...     

碳纳米管及其修饰物对挥发性有机物气敏性的研究

通过化学气相沉积(CVD)方法合成单壁碳纳米管(SWCNTs)和多壁碳纳米管(MWCNTs),并经过硝酸酸化预处理.在缩合剂N,N‘-二环己基碳化二亚胺(DCC)作用下,多壁碳纳米管经过乙二胺、十二胺和联苯胺的修饰生产新的纳米颗粒.将五种材料的悬浮液喷涂于Al2O3基底的金叉指电极上,构成气敏传感器,以甲醛、苯、甲苯、二甲苯作为测试气体,通过电化学分析仪测试他们在不同气体种类和浓度下的导电率.实验表面传感器在常温下具有较高的灵敏度和重复性,传感器之间有一定的选择性差异,可以构成传感器阵列,应用于具有复杂组分的挥发性有机气体定性和定量检测中.     

碳纳米管制备及其复合材料导热性能研究进展

随着高集成、高功率电子器件的飞速发展,电子器件对高导热材料需求更加迫切。碳纳米管 因具有独特的一维纳米结构,同时兼具优异的导热、导电和机械性能等,近年来备受国内外科研工作 者广泛的研究关注。该文主要介绍了碳纳米管的 3 种制备方法：石墨电弧法、化学气相沉积法和激光 蒸发法,同时阐述了碳纳米管导热基本机理以及碳纳米管应用于复合材料热传导性能研究,并对碳纳 米管在进一步导热研究中进行了展望。     

Chemo-sensitivity of latex-based films containing segregated networks of carbon nanotubes

In contrast to conventional hydrophobic Conductive Polymer nanoComposites (CPCs) used to design vapor sensors, which are mostly soluble in organic solvents, monodispersed acrylate copolymer latexes present the double advantage of being more sensitive and selective towards polar vapors such as water. A hierarchically structured latex based CPC film was obtained by co-dispersion of an aqueous acrylic emulsion with multiwalled carbon nanotubes (CNTs), followed by spray layer by layer (sLbL) assembly. The analysis of CPC films morphology by AFM and TEM show that a segregated network of CNT as been achieved by partial coalescence of latex nanoparticles and homogeneously assembled in 3D. Transducer sensitivity was investigated as a function of CNT content, latex glass transition temperature (T_g), organic vapor nature and vapor concentration. The source of the high sensitivity and selectivity observed for these latex-based composites towards water vapor is assumed to mainly result from ionic interaction of SDS with water molecules offering interesting perspectives of development. The different diffusion regimes through the CPC transducer are visualized, modeled and interpreted with the Langmuir-Henry-Clustering (LHC) model, showing that only water is reaching a clustering mode at high vapor concentration. Finally it is believed that the unique hierarchical architecture of BA latex-CNT sensors is responsible for their quick, stable and reproducible responses to vapors.     

半经验方法用于不同尺寸单壁纳米管的稳定性研究

利用PM3方法对不同直径(1．6-40．7A)、长度(1．2-20．9A)和类型(扶手椅型、锯齿型及手性型)的开口单壁纳米管的热力学稳定性进行了系统研究。结果表明:直径大于10 A的比较稳定;扶手椅型比其他类型的稳定;直径相同时,长度长的比短的稳定;原子数相同时,具有适当长径比的结构较为稳定;扶手椅型的电子结构主要取决于纳米管的长度,而锯齿型则取决于管的直径。所得结论与其它量化计算结果以及实验观测相符合。     

Oxygen functionalisation of MWNT and their use as gas sensitive thick-film layers

Multi-wall carbon nanotubes (MWNT) were functionalised in an oxygen-based atmosphere by an inductively coupled RF-plasma at 13.56 MHz. X-ray photoelectron spectroscopy analysis showed that the chemical composition of the nanotube surface depends on the plasma conditions used. The MWNT were then deposited onto microhotplate gas sensor substrates by the drop coating method. A well-adhered thick-film of carbon nanotubes mesh (∼17 μm) was obtained after annealing in air. The influence of the different plasma conditions on the responsiveness of gas sensors fabricated with the functionalised MWNT was studied. The gas sensing properties were investigated both experimentally and theoretically for NO₂, and NH₃ at room temperature.