聚（3,4-乙烯二氧噻吩）纳米结构及碳纳米粒子热电材料的制备及其性能研究
发布时间：2018-08-14 15:16
【摘要】：随着能源短缺和资源利用率低等问题的日益突出,作为可以实现热能和电能直接相互转化的热电材料受到了广泛的关注。有机导电聚合物以及高性能的碳纳米粒子已经成为热电材料研究的重点对象。本论文主要研究了后处理对纳米结构导电聚合物热电性能的影响以及利用碳纳米粒子为原料制备高性能的热电材料。主要内容包括以下几点:1.以3,4-乙烯二氧噻吩(EDOT)为原料,利用水相表面活性剂法和反相胶束法制备了聚(3,4-乙烯二氧噻吩)(PEDOT)纳米棒,并研究其热电性能;然后利用不同浓度的硫酸对反相胶束法制备出的PEDOT纳米棒进行浸泡处理,接着用一定质量分数的亚硫酸钠溶液对硫酸浸泡处理过的PEDOT纳米棒进行不同时间的化学还原。研究发现:后处理有效地调节了PEDOT纳米棒的氧化水平和掺杂水平,并且改善了分子链的规整度和极化状态,从而实现了PEDOT纳米棒热电性能的显著提升。2.以氧化石墨烯和酸化单壁碳纳米管为原料,通过化学还原的方法制备杂化气凝胶材料,并测试不同原料配比下气凝胶材料的孔隙率和各项热电参数。研究发现:气凝胶的特殊网络结构为电子的传输提供了多重路径,从而提高了电导率;丰富的界面使气凝胶展现了更好的能量过滤效应,从而提高了Seebeck系数;超高的孔隙率有效地抑制了声子的传输,使得气凝胶材料具有极低的热导率;综上使得气凝胶热电材料具有较高的热电优值。另外,气凝胶对不同的有机溶剂具有较高的吸收效率,且对低沸点有机溶剂表现出较好的循环使用性,多次循环使用后吸收效率没有出现明显降低。3.通过对单壁碳纳米管进行酸化处理,在其表面引入羧酸基团;然后利用水合肼作为还原剂,以硫代钼酸铵作为MoS2纳米粒子的前驱体,经过有效的还原得到了性能稳定的MoS2/a-SWCNT N-型热电材料。由于有效地对单壁碳纳米管的表面修饰和掺杂,使单壁碳纳米管的导电类型由空穴导电变为电子导电,即由P型半导体转变为N型半导体。同时,MoS2/a-SWCNT N-型热电材料具有较高的性能稳定性,且在空气中,材料的热电性能几乎不会随时间的延长而出现衰减。
[Abstract]:With the shortage of energy and the low utilization of resources, the thermoelectric materials, which can realize the direct conversion of heat energy and electricity energy, have been paid more and more attention. Organic conductive polymers and high-performance carbon nanoparticles have become the focus of thermoelectric materials. In this paper, the effect of post-treatment on the thermoelectric properties of nanostructured conductive polymers and the preparation of high performance thermoelectric materials using carbon nanoparticles as raw materials were studied. The main content includes the following points: 1. ) (PEDOT) nanorods were prepared by using aqueous surfactant method and reverse micellar method from 3O4-ethylenedioxythiophene (EDOT). The thermoelectric properties of the nanorods were studied. Then the PEDOT nanorods prepared by reverse micellar method were soaked with different concentrations of sulfuric acid, and then the PEDOT nanorods soaked in sulfuric acid were chemically reduced for different time with sodium sulfite solution of a certain mass fraction. It is found that the oxidation level and doping level of PEDOT nanorods are adjusted effectively by the post-treatment, and the molecular chain regularity and polarization state are improved, so that the thermoelectric properties of PEDOT nanorods can be improved significantly. 2. Hybrid aerogel materials were prepared by chemical reduction from graphene oxide and acidified single-walled carbon nanotubes. The porosity and thermoelectric parameters of aerogel materials with different ratios were measured. It is found that the special network structure of aerogels provides multiple paths for electron transmission, which improves the conductivity of aerogels, and the rich interface makes aerogels exhibit better energy filtering effect, thus increasing the Seebeck coefficient. The high porosity effectively inhibits the phonon transport and makes the aerogel material have a very low thermal conductivity. In summary, the aerogel thermoelectric material has a higher thermoelectric value. In addition, aerogels have higher absorption efficiency for different organic solvents, and better recycling performance for low boiling point organic solvents. The absorption efficiency of aerogels does not decrease significantly after repeated recycling. Carboxylic groups were introduced on the surface of single-walled carbon nanotubes by acidification, and then hydrazine hydrate was used as reducing agent and ammonium thiomolybdate as precursor of MoS2 nanoparticles. A stable MoS2/a-SWCNT N-type thermoelectric material was obtained by effective reduction. Due to the effective surface modification and doping of single walled carbon nanotubes, the conduction type of single walled carbon nanotubes is changed from hole conduction to electron conduction, that is, from P type semiconductor to N type semiconductor. At the same time, MoS _ 2 / a-SWCNT N- type thermoelectric materials have high performance stability, and in air, the thermoelectric properties of the materials almost do not decay with the prolongation of time.
【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1;TB34
本文编号：2183270
[Abstract]:With the shortage of energy and the low utilization of resources, the thermoelectric materials, which can realize the direct conversion of heat energy and electricity energy, have been paid more and more attention. Organic conductive polymers and high-performance carbon nanoparticles have become the focus of thermoelectric materials. In this paper, the effect of post-treatment on the thermoelectric properties of nanostructured conductive polymers and the preparation of high performance thermoelectric materials using carbon nanoparticles as raw materials were studied. The main content includes the following points: 1. ) (PEDOT) nanorods were prepared by using aqueous surfactant method and reverse micellar method from 3O4-ethylenedioxythiophene (EDOT). The thermoelectric properties of the nanorods were studied. Then the PEDOT nanorods prepared by reverse micellar method were soaked with different concentrations of sulfuric acid, and then the PEDOT nanorods soaked in sulfuric acid were chemically reduced for different time with sodium sulfite solution of a certain mass fraction. It is found that the oxidation level and doping level of PEDOT nanorods are adjusted effectively by the post-treatment, and the molecular chain regularity and polarization state are improved, so that the thermoelectric properties of PEDOT nanorods can be improved significantly. 2. Hybrid aerogel materials were prepared by chemical reduction from graphene oxide and acidified single-walled carbon nanotubes. The porosity and thermoelectric parameters of aerogel materials with different ratios were measured. It is found that the special network structure of aerogels provides multiple paths for electron transmission, which improves the conductivity of aerogels, and the rich interface makes aerogels exhibit better energy filtering effect, thus increasing the Seebeck coefficient. The high porosity effectively inhibits the phonon transport and makes the aerogel material have a very low thermal conductivity. In summary, the aerogel thermoelectric material has a higher thermoelectric value. In addition, aerogels have higher absorption efficiency for different organic solvents, and better recycling performance for low boiling point organic solvents. The absorption efficiency of aerogels does not decrease significantly after repeated recycling. Carboxylic groups were introduced on the surface of single-walled carbon nanotubes by acidification, and then hydrazine hydrate was used as reducing agent and ammonium thiomolybdate as precursor of MoS2 nanoparticles. A stable MoS2/a-SWCNT N-type thermoelectric material was obtained by effective reduction. Due to the effective surface modification and doping of single walled carbon nanotubes, the conduction type of single walled carbon nanotubes is changed from hole conduction to electron conduction, that is, from P type semiconductor to N type semiconductor. At the same time, MoS _ 2 / a-SWCNT N- type thermoelectric materials have high performance stability, and in air, the thermoelectric properties of the materials almost do not decay with the prolongation of time.
【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1;TB34
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