本文選題：熱電性質(zhì) + 單壁碳納米管　； 參考：《青島科技大學》2017年碩士論文

【摘要】：在化石能源即將枯竭的背景下,能源的有效利用顯得至關重要,然而人類工業(yè)生產(chǎn)和日常生活產(chǎn)生的熱能大部分以擴散形式被浪費掉。熱電材料是一種能將熱能直接轉(zhuǎn)化為電能的材料,吸引著人們研究它并將其用于能量回收。近年來,有機/無機復合的熱電材料相比較于無機熱電材料,具有柔性好、熱導率低、成本低、無移動相或流體,從而引起人們的極大關注。迄今為止p型有機/無機復合熱電材料的發(fā)展已經(jīng)取得巨大進步,然而發(fā)展n型有機/無機復合熱電材料依然面對巨大的挑戰(zhàn)。本文的研究工作主要集中在基于單壁碳納米管與有機小分子復合制備n型熱電材料,包括以下三部分內(nèi)容:1、我們利用SWCNT與有機小分子DETA通過溶液共混的方法制備了SWCNT/DETA復合材料,然后通過CaH2再次還原得到一種高性能的n型復合熱電材料。該材料Seebeck系數(shù)和電導率分別為-41.0±1.5μV K-1,160±10 S cm-1。我們利用掃描電子顯微鏡和吸收紅外光譜對復合材料的微觀形貌和組分進行了表征,并且闡釋了單壁碳納米管經(jīng)過摻雜由p型導電轉(zhuǎn)變?yōu)閚型導電的機理模型,用以指導材料的摻雜。最后我們基于該材料制備了性能優(yōu)異的熱電器件,經(jīng)過測試,由14個p-n結(jié)構(gòu)成的熱電器件在溫度梯度為55 K條件下,可產(chǎn)生62 mV的開路電壓和649 nW輸出功率。2、設計合成了有機導電小分子傒酰亞胺(PDINE)、萘酰亞胺(NDINE)并制備了具有n型特性的SWCNT/PDINE和SWCNT/NDINE納米復合材料。較高的電導率和Seebeck系數(shù)使得材料展現(xiàn)出非常高的PF值(135?14μW m-1 K-2),在當前n型有機熱電材料中最高的性能之一。然后我們利用該材料構(gòu)成五個p-n結(jié)的熱電器件,經(jīng)過測試,該器件在溫度梯度為50 K下,展現(xiàn)出很大的輸出功率3.3μW。同時我們還利用了熱重分析,測試了復合材料的熱穩(wěn)定性,相比較于其他有機熱電材料,這種n型有機熱電復合材料具耐高溫特性(≥200℃),極大拓展了材料的應用溫度范圍。3、簡單制備了基于氧化還原反應的SWCNT/PMMA復合水凝膠溫差熱電池材料,不僅僅避免了溫差熱電池液態(tài)電解液造成使用上的不方便,而且由于SWCNT的增強作用提供了復合材料的更好的機械性能。同時SWCNT給體系所帶來的網(wǎng)絡結(jié)構(gòu)滲透過濾效應、表面極化等促進了Sn2+/Sn4+氧化還原對遷移,使得熱電池材料展現(xiàn)出了較大的Seebeck系數(shù)(1200μV K-1)和電導率(0.11 S cm-1)。
[Abstract]:Under the background that fossil energy is about to be exhausted, the effective utilization of energy is very important. However, most of the heat energy produced by human industrial production and daily life is wasted in the form of diffusion. Thermoelectric material is a kind of material which can convert heat energy directly into electric energy, which attracts people to study it and use it for energy recovery. In recent years, compared with inorganic thermoelectric materials, organic / inorganic composite thermoelectric materials have the advantages of good flexibility, low thermal conductivity, low cost and no moving phase or fluid. So far, great progress has been made in the development of p-type organic / inorganic composite thermoelectric materials, but the development of n-type organic / inorganic composite thermoelectric materials still faces great challenges. In this paper, we mainly focus on the preparation of n-type thermoelectric materials based on single-walled carbon nanotubes and organic small molecules, including the following three parts: 1. We prepared SWCNT/DETA composites by solution blending with SWCNT and organic small molecules DETA. Then a high performance n-type composite thermoelectric material was obtained by CaH2 rereduction. The Seebeck coefficient and conductivity are -41.0 鹵1.5 渭 V K-1160 鹵10S cm-1, respectively. The microstructure and composition of the composites were characterized by scanning electron microscopy (SEM) and absorption infrared spectroscopy (IR), and the mechanism model of the transition from p-type conduction to n-type conduction of single-walled carbon nanotubes was explained. Used to guide the doping of materials. Finally, we have fabricated thermoelectric devices with excellent performance based on the material. After testing, the thermoelectric devices with 14 p-n structures are fabricated at a temperature gradient of 55 K. The open circuit voltage of 62mV and the output power of 649nW were obtained. The organic conductive small molecular molecules, SWCNT/PDINE and SWCNT/NDINE nanocomposites with n-type properties were designed and synthesized. The high conductivity and Seebeck coefficient make the material exhibit a very high PF value of 135V 14 渭 W m-1 K-2O, which is one of the highest properties in n-type organic thermoelectric materials. Then we use the material to form five p-n junction thermoelectric devices. The test results show that the device has a high output power of 3.3 渭 W at a temperature gradient of 50 K. At the same time, we also used thermogravimetric analysis to test the thermal stability of the composite, compared with other organic thermoelectric materials. The n-type organic thermoelectric composite has the characteristics of high temperature resistance (鈮，

本文編號：1813195