【作者】 张蕾；

【导师】 刘锦淮；

【作者基本信息】 中国科学技术大学 ， 无机化学， 2010， 硕士

【摘要】 纳米材料的有序微阵列体系的制备对于规模化功能器件如传感器等的研制具有重要的意义。阳极氧化铝模板(AAO)具有高度有序的阵列结构,而且制备工艺简单、易于工业化生产等特点,用氧化铝模板制备纳米材料有序阵列体系已被视为最有前途的方法之一。本文主要研究了采用AAO模板电化学合成聚吡咯纳米线阵列结构,将聚吡咯纳米线阵列利用半导体工艺制做成了气体传感器,用来检测氨气,并对其响应原理给出了解释。另外,本论文还探讨了聚吡咯阵列器件检测挥发性有机化合物的蒸气,初步探讨了聚吡咯纳米线阵列测试溶液中的挥发性有机物。论文第一章介绍了导电聚合物的发展、导电机制和应用,导电聚吡咯材料的发现和合成方法,以及在传感器方面的应用,最后介绍了挥发性有机化合物的危害及其检测方法。论文第二章主要研究了恒压下有序阳极氧化铝模板的制备,将氧化铝模板一面蒸金后作为工作电极,采用三电极,在不同溶剂中用电化学方法恒电位合成聚吡咯纳米线阵列结构。用扫描电子显微镜、红外光谱、XPS、XRD对水溶液中合成的聚吡咯纳米线进行了形貌、结构和结晶程度的表征和分析。论文第三章以聚吡咯纳米线为气敏材料,制备了阵列式气体传感器,测量了器件对氨气的响应,氨气是一种富电子气体,与聚吡咯纳米线作用后,聚吡咯结构中的空穴减少,引起电阻的变化。由于聚吡咯纳米线阵列中存在大量的气体扩散空间,而且纳米线直径较小,所以制备的传感器对气体的吸附和脱附速度快,响应和恢复时间短,灵敏度也有很大提高,而且在1.5 ppm-77 ppm范围内,氨气浓度的倒数与灵敏度的倒数成线性关系。对气体的响应机理也给出了合理的解释。第四章主要利用聚吡咯纳米线阵列结构的电阻变化检测了丙酮、间二甲苯挥发性有机化合物,利用电容信号的变化初步研究了聚吡咯纳米线阵列电容器对溶剂(正己烷)中邻二氯苯的检测。最后对论文的工作进行了总结,并对下一步工作提出了展望。更多还原

【Abstract】 The fabrication of ordered array nano structures is important for obtaining scaled-up functional devices such as sensors devices. Anodic aluminum oxide (AAO) templates have high ordered nanochannel array structures, easy preparation technology and industrial production. It is one of the promising strategies to use AAO templates to prepare ordered array nano structures.In this paper, polypyrrole (PPy) nanowire arrays were synthesized in AAO templates by elecctrochemical method. The PPy nanowire arrays sensor was fabricated by semiconductor technology and was used to detecte ammonia. In addition, this paper had a study on the vapor of volatile organic compounds (VOCs), such as acetone, m-xylene, by PPy nanowires arrays. A preliminary research on detecting the o-dichlorobenzene in n-hexane by arrays was also studiedIn the first chapter, we introduced the development of the conducting polymers, their conductive mechanism and their applications. We presented the discovery of the material of PPy, its synthesis methods and its applications, sensors for example. Moreover, we generalized the harm of volatile organic compounds and detecting ways.Chapter 2 mainly studied the preparation of AAO templates. The highly ordered AAO templates with hexagonal pore structures were fabricated by two-step anodization under constant temperature. Meanwhile, we studied the fabrication of highly ordered PPy nanowire arrays in AAO template by electrochemical method under constant potential in different solvent. One sides of AAO was deposited a thin layer of Au and it was used to working electrode. The morphology and structure of PPy nanowire synthesized in distilled water were analyzed by a field emmission scanning electron microscope (SEM), FT-IR spectrum, and X-ray Photoelectron Spectroscopy. The crystallinity was examined by X-ray Diffraction.In chapter 3, the gas sensor based on vertically aligned polypyrrole nanowire arrays was fabricated and investigated. The fastness of the device was improved by deposited Au. In ambient atmosphere, we have investigated the response of the sensor to low concentrations of ammonia. Ammonia exhibited some electron rich and PPy doped with ClO4ˉwhich carries many electron holes. When ammonia was absorbed on the nanowires, it can donate electrons to the initially oxidized PPy and change the resistance of PPy. Our results indicated that PPy nanowire arrays had high sensitivity, relatively short response time and recovery time for ammonia. The reciprocal of response degree has a linear relationship with the reciprocal of gas concentration (1.5 ppm-77 ppm). The possible mechanism of the response was also discussed.In chapter 4, we had a preliminary study on the detection of volatile organic compounds based on the arrays structure of PPy nanowire such as acetone, m-xylene. According to the change of capacitance signal, we detect the o-dichlorobenzene in n-hexane by PPy nanowires arrays preliminary.At the end of this paper, a short conclusion for the work and the goal of future research were made.更多还原