聚苯胺@碳纳米管复合材料的制备与功能特性研究

发布时间：2018-03-18 20:38

  本文选题：聚苯胺　切入点：碳纳米管　出处：《西南交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：以聚苯胺(Polyaniline, PANi)、多壁碳纳米管(Multi-walled Carbon Nanotubes, MWCNTs)以及螺旋碳纳米管(Helical Carbon Nanotubes, HCNTs)为研究对象,采用原位聚合制备了系列聚苯胺@碳纳米管复合结构(PANi@CNTs),探索组分含量以及掺杂酸类型等因素对产物形貌和结构的影响；研究了PANi@CNTs的电磁学性能和电磁波损耗特性,以及聚苯胺与两类碳纳米管复合结构的气敏特性。主要研究内容及结果如下：以HCl为掺杂酸,过硫酸铵作为氧化剂,通过苯胺原位聚合制备了一维PANi复合CNTs复合结构；表征结果表明,PANi以纳米棒形式覆盖在CNTs表面,且二者之间存在特殊相互作用。通过改变反应条件,可以得到不同内外径和壁厚的PANi@CNTs复合结构,其直径随CNTs的质量百分比的增加而降低；PANi与CNTs之间的相互作用随CNTs质量百分比增加而增加。手性樟脑磺酸掺杂下的PANi@CNTs,其PANi的氧化程度更高,HCl掺杂PANi@CNTs产物表面形貌相对更均匀。分别测试了PANi@CNTs复合结构的电导率,其中PANi@MWCNTs的电导率随MWCNTs的含量增加而增加,手性酸掺杂PANi会降低PANi@MWCNTs的电导率；PANi@HCNTs的电导率在HCNTs含量小于5 wt%时随HCNTs含量增加而增加,高于10 wt%时随HCNTs含量增加而降低。当MWCNTs含量为10 wt%时,PANi@MWCNTs复合结构具有最好的微波损耗性能,相应的电磁波损耗主要集中在相对低频的2-6 GHz区域,最强反射率衰减(-23 dB)位于4.7 GHz处。分析认为,PANi@MWCNTs复合结构对微波的损耗机制主要为低频涡流损耗；手性酸掺杂PANi使得复合结构的微波损耗由低频向高频区移动。当HCNTs含量为20 wt%时,复合结构具有最好的微波吸收性能,最强反射率衰减(-31 dB)位于17.2 GHz；PANi@HCNTs复合结构对微波的损耗机制主要为界面极化引起的介电弛豫损耗,以及HCNTs手性特性引起的电磁交叉极化和多重极化引起的弛豫损耗,使材料在中频区域表现出磁损耗；手性酸掺杂PANi使得复合结构的微波损耗由低频向中高频区域移动。测试了PANi@CNTs复合结构在NH3浓度为10-100 ppm范围内的气敏传感器性能,结果显示PANi@CNTs复合结构对NH3有较好的电导率响应,且随NH3浓度的增加而增加。CNTs含量可以影响PANi@CNTs复合结构对NH3的响应灵敏度。复合结构中,MWCNTs含量5wt%、HCNTs质量百分比为20wt%时,传感器对NH3响应的灵敏度整体最佳。手性酸掺杂PANi可显著提升PANi@MWCNTs对NH3响应的灵敏度,但是会降低PANi@HCNTs对NH3响应的灵敏度感。
[Abstract]:Polyaniline, PANiN, Multi-walled Carbon Nanotubeses (MWCNTs) and Helical Carbon Nanotubeses (HCNTs) were studied. A series of Polyaniline @ carbon nanotube composite structures were prepared by in-situ polymerization to explore the effects of composition content and the type of doped acid on the morphology and structure of the products, and to study the electromagnetic properties and electromagnetic wave loss characteristics of PANi@CNTs. The main contents and results are as follows: one dimensional PANi composite CNTs structure was prepared by in situ polymerization of aniline with ammonium persulfate as oxidant and HCl as doping acid. The characterization results show that the CNTs surface is covered with nanorods, and there is a special interaction between them. By changing the reaction conditions, the PANi@CNTs composite structures with different inner and outer diameters and wall thickness can be obtained. The diameter decreases with the increase of mass percentage of CNTs, and the interaction between CNTs and Pani increases with the increase of mass percentage of CNTs. The oxidation degree of PANi is higher than that of PANi@CNTs products doped with chiral camphor sulfonic acid (camphor sulfonic acid). The conductivity of PANi@CNTs composite structure was measured. The conductivity of PANi@MWCNTs increased with the increase of MWCNTs content, and the conductivity of PANi@MWCNTs increased with the increase of HCNTs content when the content of HCNTs was less than 5 wt%. When the MWCNTs content is 10 wt%, the microwave loss of the composite structure is the best, and the corresponding electromagnetic wave loss is mainly in the 2-6 GHz region of relatively low frequency. The strongest reflectivity attenuation is at 4. 7 GHz. It is considered that the loss mechanism of PANiR MWCNTs composite structure to microwave is mainly low frequency eddy current loss. Chiral acid doped PANi makes the microwave loss of the composite structure move from low frequency to high frequency. When the content of HCNTs is 20 wt%, the composite structure has the best microwave absorption performance. The mechanism of microwave loss of the strongest reflectivity attenuated band (-31 dB) is mainly caused by interfacial polarization, electromagnetic cross-polarization caused by chiral properties of HCNTs and relaxation loss caused by multiple polarization. Chiral acid doped PANi makes the microwave loss of the composite structure move from low frequency to middle high frequency. The gas sensor performance of PANi@CNTs composite structure in the range of 10 to 100 ppm NH3 concentration is tested. The results show that the composite structure of PANi@CNTs has a good conductivity response to NH3, and the content of. CNTs can affect the sensitivity of PANi@CNTs composite structure to NH3 with the increase of NH3 concentration. When the content of PANi@CNTs in the composite structure is 5 wtts, the mass percentage of PANi@CNTs is 20 wt%. The overall sensitivity of the sensor to NH3 response is the best. Chiral acid-doped PANi can significantly enhance the sensitivity of PANi@MWCNTs to NH3 response, but reduce the sensitivity of PANi@HCNTs to NH3 response.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB332

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