氧化钒—定向碳纳米管复合膜的制备与特性研究

发布时间：2018-01-17 13:28

  本文关键词：氧化钒—定向碳纳米管复合膜的制备与特性研究　出处：《电子科技大学》2015年硕士论文　论文类型：学位论文

  更多相关文章： 氧化钒 定向性碳纳米管 吹泡法 电学特性 光学特性

【摘要】：自然界中,偏振光广泛存在。利用偏振光可在沙尘、水下等特殊条件下成像、导航,甚至用于诊断癌细胞等。奇妙的是,很多动物进化出了感知入射偏振信号的能力,如蜜蜂通过感知紫外偏振光导航,螳螂虾利用偏振光在水下辨别方向等。可惜人类没有该感知力。然而,一些微纳功能薄膜有望赋予人类该感知力,如“面内”定向的碳纳米管薄膜。由于碳纳米管的分散及排列较难,而单根碳纳米管与光子弱相互作用,所以关于定向碳纳米管薄膜偏振成像的相关研究报道较少。然而,由于碳纳米管温度热敏系数较低等原因,所以本文希望通过其与热敏材料复合来实现偏振响应。在众多热敏材料中,氧化钒由于综合性能较好而备受业界关注。本论文的主要研究内容是氧化钒-定向碳纳米管的复合薄膜的制备与性能研究。首先,优化了制备氧化钒薄膜的工艺参数。采用溶胶-凝胶法,在不同反应温度和退火时间条件下制备了不同的氧化钒薄膜。对溶胶化学结构及相关薄膜的电学、光学性能等进行了系统研究。研究优化了两个工艺参数对所制备薄膜形态及性能的影响：(a)不同溶胶的反应温度：反应温度条件为110℃时,更利于氧化钒溶胶网络(O=V-O-V=O)的生成。与其它反应温度制得的薄膜相比,相应薄膜具有最低的电阻(5.5-8.5 MΩ),且TCR较高,有更低的红外波段透过率；(b)不同的退火时间：与其它退火时间制得的薄膜相比,退火时间1 h,电阻较低(13-32MΩ), TCR较高,且在红外波段吸收率较高。退火时间宜介于0.5-2小时。其次,在优化了氧化钒溶胶的制备工艺的基础上,通过溶胶-凝胶法,使功能化碳纳米管与氧化钒相复合,制备氧化钒-随机取向碳纳米管复合薄膜。与单纯的氧化钒薄膜相比,氧化钒-碳纳米管复合膜的方阻和光学带隙减小,而电阻温度系数和光吸收率相应增大,而且,复合膜还具有更高的载流子迁移速率。最后,采用新颖的吹泡法,将碳纳米管定向排列。然后,在基于前述已经优化了的氧化钒溶胶制备工艺及复合薄膜性能的基础上,结合传统的旋涂法将定向的碳纳米管转移至已经旋涂有氧化钒溶胶的基底上并进行退火处理,制备氧化钒-定向碳纳米管复合薄膜。结果显示,碳纳米管被很好地可控定向并与氧化钒均匀融合。特别是,该复合薄膜的电学、光学各向异性被首次实验观测到。基于上述实验结果,建立推导了光学吸收模型。该文揭示了有价值的新型氧化钒-定向性碳纳米管复合薄膜的制备及特异电学、光学性能,及其在偏振成像方面的潜在价值。
[Abstract]:In nature, polarized light widely exists. The use of polarized light can be used in dust, underwater and other special conditions imaging, navigation, and even for the diagnosis of cancer cells. Many animals have evolved the ability to sense incident polarized signals, such as the ability of bees to navigate by sensing ultraviolet polarized light, and mantis shrimp to use polarized light to identify directions under water. Unfortunately, humans do not have this perception. Some micro and nano functional thin films are expected to give the human perception, such as "in-plane" oriented carbon nanotube films. Because of the difficult dispersion and arrangement of carbon nanotubes, single carbon nanotubes interact weakly with photons. Therefore, there are few reports on the polarization imaging of oriented carbon nanotubes films. However, due to the low temperature sensitivity coefficient of carbon nanotubes and so on. Therefore, this paper hopes to achieve polarization response through its composite with thermosensitive materials, in many thermosensitive materials. Vanadium oxide has attracted much attention due to its good comprehensive properties. The main research content of this thesis is the preparation and properties of vanadium oxide / oriented carbon nanotubes composite films. The process parameters of vanadium oxide thin films were optimized. Different vanadium oxide thin films were prepared under different reaction temperature and annealing time by sol-gel method. The effects of two technological parameters on the morphology and properties of the films were studied and optimized. The reaction temperatures of different sols were optimized: the reaction temperature was 110 鈩，

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