超重力强化制备纳米聚苯胺及其功能化复合材料研究

发布时间：2018-03-07 10:00

本文选题：超重力旋转床　切入点：聚苯胺　出处：《北京化工大学》2015年博士论文　论文类型：学位论文

【摘要】：纳米聚苯胺因具有原料易得、合成简便、良好的导电性、独特的氧化还原特性、相对较好的溶解性等特点,引起了人们的广泛重视和研究。化学氧化聚合法是可规模化制备纳米聚苯胺的重要方法之一,而超重力是重要的化工过程强化新技术。建立在这两种技术基础之上,本课题组成功首创了超重力化学氧化聚合法(简称超重力法),成为可规模化合成高性能纳米聚苯胺纤维的一个新方法。为了进一步优化工艺并提高产品性能,本论文研究了不同工艺对超重力法制备聚苯胺过程和产品性能的影响及影响机理,确定以超重力间歇工艺为主要研究对象,并以此为基础,研究添加剂对该制备过程和所得产品性能的影响和机理,得到了形貌和性能优异的聚苯胺纳米纤维及聚苯胺复合材料。主要研究内容如下：1.考察了超重力法制备聚苯胺工艺对产品的影响,结果表明：采用超重力间歇工艺得到了聚苯胺纳米纤维,与机械搅拌法所得产品相比,该产品的组成、结构、分子量以及电化学稳定性等区别不大,但比表面积(49.1 m2/g)和电导率(108.1 S/m)分别增大了26.2%和15.2%,提高了聚苯胺在电化学反应时的有效利用率和电子传导速率,使比电容(667.6 F/g)增大了77.6%。采用了超重力循环工艺制备出了边长为100-150 nm的立方体聚苯胺纳米颗粒,随温度升高该颗粒有向纤维转变的趋势。在干燥的过程中该颗粒会发生二次团聚,形成聚苯胺纤维。这种立方体颗粒的形成可能是由于超重力旋转床中强烈的混合作用打破了聚苯胺颗粒组装成聚苯胺纤维的过程。由于间歇工艺的重复性和产品的比表面积较高,对聚苯胺导电性和电化学性能有直接影响,因此选择超重力间歇法作为后续研究的基础。2.为改善聚苯胺纳米纤维的形貌及性能,采用N-苯基对苯二胺(AD)和对苯二胺(AP)作为添加剂,考察了添加剂用量、反应温度、旋转床转速等对产品性能的影响。结果表明：AD和AP均能促进聚苯胺纤维的生长,所得聚苯胺的平均长径比最高分别可达19.4和37.4,比电容最高分别为527.5和552 F/g。比电容增大的原因是这两种添加剂的氧化电势较低,先于苯胺成核,加速反应的进行,使超重力旋转床中的聚合反应更趋近于均相成核,得到高长径比的聚苯胺纤维,从而提高聚苯胺在电化学反应中的有效利用率和电子传输速率。此外,添加剂的分子结构对产品的形貌也有重要影响。3.以多壁碳纳米管为添加剂,研究它对超重力法制备纳米聚苯胺过程的影响和影响机理,考察了多壁碳纳米管含量、碳纳米管表面官能团等因素对产品形貌及导电性能的影响,得到了聚苯胺/多壁碳纳米管复合材料。结果表明：聚苯胺在多壁碳纳米管上可包覆形成均匀的核壳结构(直径30-50 nm)。接枝在多壁碳纳米管上的苯胺基团参与了苯胺的聚合,并与聚苯胺之间形成共价键。多壁碳纳米管的加入形成了导电通道,可使聚苯胺的电导率增大9倍。与机械搅拌法相比,超重力法由于其良好的微观混合作用,有利于获得包覆均匀的产品。4.以石墨烯为添加剂,研究它对超重力法制备纳米聚苯胺过程的影响和影响机理,考察了石墨烯含量、苯胺浓度、氧化剂／苯胺摩尔比等因素对产品性能的影响,得到了聚苯胺／石墨烯复合材料。结果表明：聚苯胺在石墨烯片层上可形成均匀的包覆层,厚度可在20-40nm之间调节。由于聚苯胺和石墨烯之间的协同效应,所得产品的比电容达到403 F/g,较纯聚苯胺提高了26%。在保证石墨烯分散良好的情况下,提高苯胺浓度对产品性能影响不大。在适当的氧化剂用量下,产品的比电容最高可达542 F/g。产品的形貌对比电容有较大影响,是因为均匀且薄的包覆层能暴露出更多的聚苯胺表面,提高聚苯胺在电化学反应中的有效利用率。
[Abstract]:Because nanopolyaniline has easy to obtain material, easy synthesis, good conductivity, unique redox properties, relative solubility characteristics such as good, has attracted wide attention and research. Chemical oxidative polymerization is one of the important methods for large-scale preparation of nano polyaniline, and super gravity is a new technology of chemical process an important enhancement. Based on these two kinds of technology foundation, the research group successfully pioneered the high gravity chemical oxidative polymerization (referred to as hgcop), has become a new method for large-scale synthesis of high performance nano polyaniline fiber. In order to further optimize the process and improve the performance of the products, we have investigated the mechanism of different effect of process parameters on the super gravity polyaniline prepared process and product performance and effect, in order to determine the high gravity batch process as the main research object, and based on this, the research on the preparation process of additive preparation Influence and mechanism and the performance of the product, the morphology and performance of polyaniline nanofibers and polyaniline composite materials. The main contents are as follows: 1. the effects of polyaniline process on the impact of products, the results showed that super gravity method: using high gravity batch process by polyaniline nanofibers, compared with mechanical mixing method of the product the product, composition, structure, molecular weight and electrochemical stability of the difference is not big, but the specific surface area (49.1 m2/g) and electrical conductivity (108.1 S/m) were increased by 26.2% and 15.2%, improve the effective utilization rate of poly aniline and electronic conduction in the electrochemical reaction, the specific capacitance (667.6 F/g). 77.6%. uses a super gravity circulation process to fabricate the polyaniline nanoparticles cube side length of 100-150 nm, with the increase of the temperature of the particles to the fiber change trend in the dry. Two of the particles will reunite in the process of forming polyaniline fiber. Formation of this cube particles may be due to the strong mixing effect in RPB has broken the polyaniline particles assembly process of polyaniline fiber. Because of the repeated batch process and product of the high specific surface area, has a direct effect on the conductivity of Polyaniline and the electrochemical properties, so the choice of super gravity batch method as the basis for further research of.2. morphology and improve the performance of polyaniline nanofibers, using N- phenyl-p-phenylene two amine (AD) and two of benzene amine (AP) as additive, effects of additive dosage, reaction temperature, influence of rotating speed on the properties of the product. The results showed that AD and AP could promote the growth of polyaniline fibers, the average length of the PANI diameter ratio respectively 19.4 and 37.4, the highest specific capacitance were 527.5 F/ and 552 g. capacitance The reason is the increased oxidation potential of the two kinds of additives is low, prior to aniline nucleation, accelerate the reaction, the polymerization reaction is more close to the high gravity rotating bed in homogeneous nucleation, high aspect ratio of the polyaniline fiber, thereby improving the electrochemical reaction of Polyaniline in the effective utilization rate and electron transport rate. In addition, the molecular structure of additives on the morphologies of the products also have an important influence on.3. multi walled carbon nanotubes as additives and study its effect on the preparation of nano polyaniline super gravity process and influence mechanism, effects of multi walled carbon nanotubes content, effect of carbon nanotubes surface functional groups on the product morphology and conductive properties, get polyaniline / multi walled carbon nanotubes composites. The results showed that polyaniline in multi walled carbon nanotubes can be coated to form a core-shell structure with uniform (30-50 nm diameter). The grafted multi walled carbon nanotubes Tube in the aniline radical polymerization of aniline, the formation of a covalent bond between and polyaniline. The addition of MWNTs to form a conductive channel, the conductivity of polyaniline increased 9 times. Compared with mechanical mixing method, high gravity method due to its good micromixing effect, is beneficial to obtain evenly coated products.4. with graphene as additives to study its effect on the preparation of nano polyaniline super gravity process and influence mechanism, effects of the content of graphene, the concentration of aniline, oxidant / aniline molar ratio on the performance of the product, the polyaniline / graphene composite materials. The results showed that polyaniline can form a uniform coating on graphene layers, the thickness can be adjusted between 20-40nm. Due to the synergistic effect between polyaniline and graphene, the specific capacitance of 403 F/g, increased by 26%. in a pure Polyaniline Ensure the graphene dispersion is good, increase the concentration of aniline has little effect on the performance of the product. The amount of oxidant under the proper ratio of the product morphology contrast capacitance up to 542 F/g. products have a greater impact, because the coating layer is uniform and thin to expose the surface of polyaniline more, improve the effective use of Polyaniline in the electrochemical reaction rate.

【学位授予单位】：北京化工大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TQ340.1;TB33

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