L-纈氨酸輔助合成聚苯胺花狀納米結(jié)構(gòu)的機(jī)理研究
發(fā)布時(shí)間：2018-09-18 19:59
【摘要】：有機(jī)導(dǎo)電高分子材料在太陽(yáng)能電池、發(fā)光二極管、氣敏傳感器以及可控電極方面有廣泛的應(yīng)用。和無(wú)機(jī)材料相比,它們具有優(yōu)良的加工性,質(zhì)子酸的可摻雜性以及環(huán)境穩(wěn)定性的特點(diǎn),而且它的物理和化學(xué)穩(wěn)定性又可以通過(guò)其分子層面的設(shè)計(jì)來(lái)調(diào)控。但是目前用有機(jī)導(dǎo)電高分子材料組裝的器件它的性能表現(xiàn)次于用無(wú)機(jī)材料組裝的,其主要原因就是由于在分子、原子層面上研究高分子聚合原理的匱乏。本論文主要是以導(dǎo)電高分子聚苯胺(PANI)為模型,采用自組裝法合成三維花狀納米結(jié)構(gòu)的聚苯胺并利用核磁共振原位追蹤技術(shù)(NMR)追蹤整個(gè)反應(yīng)過(guò)程,同時(shí)再利用透射電子顯微鏡(TEM)和掃描電子顯微鏡(SEM)進(jìn)行直觀的佐證,深入分析形成三維花狀納米結(jié)構(gòu)聚苯胺的機(jī)理和可能原因。本論文不僅充實(shí)了從分子層面研究聚合物聚合體系,而且還為利用核磁共振技術(shù)從分子層面研究材料的形成機(jī)理奠定了基礎(chǔ)。本論文主要開(kāi)展了以下幾方面的工作:1)以L-纈氨酸為摻雜酸,用自組裝法制備三維花狀納米結(jié)構(gòu)聚苯胺,研究主要內(nèi)容為反應(yīng)條件對(duì)產(chǎn)物結(jié)構(gòu)的影響規(guī)律。研究表明,隨反應(yīng)中L-纈氨酸的含量增加,所制備的納米聚苯胺依次呈現(xiàn)薄片狀,花狀以及帶絨毛的片狀形貌;采用甘氨酸(與L-纈氨酸分子結(jié)構(gòu)相比缺少疏水鏈)作摻雜酸,對(duì)比研究發(fā)現(xiàn)了氨基酸和苯胺在未加APS時(shí)的初始締和狀態(tài)。2)為進(jìn)一步理解三維花狀納米聚苯胺的成核機(jī)理,利用核磁共振原位追蹤技術(shù)和二維核磁實(shí)驗(yàn)技術(shù),并結(jié)合TEM和SEM表征手段,對(duì)比花狀與非花狀納米聚苯胺形成過(guò)程中原位追蹤核磁共振氫譜及聚合后產(chǎn)物形貌的變化最終表明花狀納米聚苯胺的形成過(guò)程具有如下幾個(gè)典型特點(diǎn):①反應(yīng)初期由于L-纈氨酸具有酸堿兩性,作為緩沖試劑可以有效調(diào)節(jié)苯胺單體的質(zhì)子化程度,從而實(shí)現(xiàn)苯胺單體鄰、對(duì)位電子云密度與間位的電子云密度接近,最終有利于聚合反應(yīng)主要生成具有吩嗪結(jié)構(gòu)的寡聚物;②反應(yīng)前苯胺單體首先與纈氨酸形成較為穩(wěn)定的膠束體系,繼而反應(yīng)產(chǎn)生的寡聚物在膠束內(nèi)發(fā)生聚集,隨后通過(guò)膠束融合過(guò)程進(jìn)一步導(dǎo)致寡聚物聚集體成長(zhǎng)為基本結(jié)構(gòu)組裝單元,在這些過(guò)程中處于膠束外層的纈氨酸分子始終起到穩(wěn)定膠束與協(xié)調(diào)膠束融合的作用,導(dǎo)致組裝過(guò)程最終形成熱力學(xué)穩(wěn)定產(chǎn)物。3)考慮到片狀以及花狀聚苯胺的堆積方式,具有較大的比表面積,而且通過(guò)機(jī)理研究發(fā)現(xiàn)寡聚物結(jié)構(gòu)中存在大量的π-π重疊的共軛結(jié)構(gòu),電子離域程度較高,故推測(cè)其電化學(xué)性能較好。所以對(duì)合成的片狀和花狀結(jié)構(gòu)的聚苯胺進(jìn)行了電化學(xué)性能測(cè)試,主要運(yùn)用了循環(huán)伏安法(CV)測(cè)試和充放電性能測(cè)試,研究結(jié)果表明花狀結(jié)構(gòu)的聚苯胺比片狀具有更優(yōu)越的電化學(xué)性能,并也有一定的電容性能但仍還需改性進(jìn)一步優(yōu)化提升。
[Abstract]:Organic conductive polymer materials are widely used in solar cells, light-emitting diodes, gas sensors and controllable electrodes. Compared with inorganic materials, they have excellent processability, proton acid doping and environmental stability, and their physical and chemical stability can be regulated by their molecular design. However, the performance of the devices assembled with organic conductive polymer materials is inferior to that of inorganic materials. The main reason is the lack of research on the principle of polymer polymerization on the molecular and atomic level. In this thesis, three dimensional Polyaniline with flower-like nanostructure was synthesized by self-assembly using conductive Polyaniline (PANI) as a model, and the whole reaction process was traced by (NMR). At the same time, transmission electron microscope (TEM) and scanning electron microscope (SEM) were used to prove the mechanism and possible causes of the formation of three-dimensional flower-like nanostructure Polyaniline. This thesis not only enriches the study of polymer polymerization system at molecular level, but also lays a foundation for studying the formation mechanism of materials at molecular level by nuclear magnetic resonance (NMR). In this paper, the following work was carried out: 1) Three-dimensional flower-like Polyaniline was prepared by self-assembly method with L-valine as the doped acid. The main content of this study was the influence of reaction conditions on the structure of the product. The results showed that with the increase of Lvaline content in the reaction, the prepared nano-Polyaniline showed flake, flower-like and fluffy morphology in turn, and glycine (lacking hydrophobic chain compared with Lvaline molecular structure) was used as the doped acid. It was found that the initial association and state of amino acid and aniline without APS) were used to further understand the nucleation mechanism of three-dimensional flower-like nano-Polyaniline. NMR in situ tracing technique and two-dimensional NMR technique were used to study the nucleation mechanism of aniline. Combined with TEM and SEM characterization, The in situ tracing of nuclear magnetic resonance (NMR) spectra and the morphologies of the polymerized products during the formation of flower-like and non-flower-like nano-Polyaniline showed that the formation process of the flower-like nano-Polyaniline was characterized by the following typical characteristics: 1: 1 initial reaction Because L-valine is acid-base amphoteric, As a buffer agent, the protonation degree of aniline monomer can be adjusted effectively, so that the para-potential electron cloud density is close to that of the m-position electron cloud, so that the oligomer with phenazine structure is mainly formed in the polymerization reaction. (2) aniline monomer first formed a stable micellar system with valine before the reaction, and then the oligomers produced by the reaction gathered in the micelle. Subsequently, through micellar fusion process, the oligomer aggregates grow into basic structural assembly units. In these processes, valine molecules in the outer layer of micelles always play the role of stabilizing micelles and coordinating micelle fusion. As a result of the final formation of thermodynamically stable product .3) considering the stacking patterns of floral and floral Polyaniline, it has a large specific surface area, and it is found that there are a large number of 蟺-蟺 overlapping conjugated structures in the oligomer structure. Due to the high degree of electron delocalization, it is assumed that its electrochemical performance is better. Therefore, the electrochemical properties of Polyaniline with floral and floral structures were tested, mainly by cyclic voltammetry (CV) and charge-discharge test. The results show that Polyaniline with flower-like structure has better electrochemical performance than flaky Polyaniline, and also has some capacitance properties, but it still needs to be optimized and upgraded by modification.
【學(xué)位授予單位】：南京理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：O633.21
本文編號(hào)：2248969
[Abstract]:Organic conductive polymer materials are widely used in solar cells, light-emitting diodes, gas sensors and controllable electrodes. Compared with inorganic materials, they have excellent processability, proton acid doping and environmental stability, and their physical and chemical stability can be regulated by their molecular design. However, the performance of the devices assembled with organic conductive polymer materials is inferior to that of inorganic materials. The main reason is the lack of research on the principle of polymer polymerization on the molecular and atomic level. In this thesis, three dimensional Polyaniline with flower-like nanostructure was synthesized by self-assembly using conductive Polyaniline (PANI) as a model, and the whole reaction process was traced by (NMR). At the same time, transmission electron microscope (TEM) and scanning electron microscope (SEM) were used to prove the mechanism and possible causes of the formation of three-dimensional flower-like nanostructure Polyaniline. This thesis not only enriches the study of polymer polymerization system at molecular level, but also lays a foundation for studying the formation mechanism of materials at molecular level by nuclear magnetic resonance (NMR). In this paper, the following work was carried out: 1) Three-dimensional flower-like Polyaniline was prepared by self-assembly method with L-valine as the doped acid. The main content of this study was the influence of reaction conditions on the structure of the product. The results showed that with the increase of Lvaline content in the reaction, the prepared nano-Polyaniline showed flake, flower-like and fluffy morphology in turn, and glycine (lacking hydrophobic chain compared with Lvaline molecular structure) was used as the doped acid. It was found that the initial association and state of amino acid and aniline without APS) were used to further understand the nucleation mechanism of three-dimensional flower-like nano-Polyaniline. NMR in situ tracing technique and two-dimensional NMR technique were used to study the nucleation mechanism of aniline. Combined with TEM and SEM characterization, The in situ tracing of nuclear magnetic resonance (NMR) spectra and the morphologies of the polymerized products during the formation of flower-like and non-flower-like nano-Polyaniline showed that the formation process of the flower-like nano-Polyaniline was characterized by the following typical characteristics: 1: 1 initial reaction Because L-valine is acid-base amphoteric, As a buffer agent, the protonation degree of aniline monomer can be adjusted effectively, so that the para-potential electron cloud density is close to that of the m-position electron cloud, so that the oligomer with phenazine structure is mainly formed in the polymerization reaction. (2) aniline monomer first formed a stable micellar system with valine before the reaction, and then the oligomers produced by the reaction gathered in the micelle. Subsequently, through micellar fusion process, the oligomer aggregates grow into basic structural assembly units. In these processes, valine molecules in the outer layer of micelles always play the role of stabilizing micelles and coordinating micelle fusion. As a result of the final formation of thermodynamically stable product .3) considering the stacking patterns of floral and floral Polyaniline, it has a large specific surface area, and it is found that there are a large number of 蟺-蟺 overlapping conjugated structures in the oligomer structure. Due to the high degree of electron delocalization, it is assumed that its electrochemical performance is better. Therefore, the electrochemical properties of Polyaniline with floral and floral structures were tested, mainly by cyclic voltammetry (CV) and charge-discharge test. The results show that Polyaniline with flower-like structure has better electrochemical performance than flaky Polyaniline, and also has some capacitance properties, but it still needs to be optimized and upgraded by modification.
【學(xué)位授予單位】：南京理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：O633.21
【參考文獻(xiàn)】
相關(guān)期刊論文 前3條
1 高瑩麗;王瑞娟;劉空;武曉東;;利用核磁共振技術(shù)研究聚苯胺納米棒的成核機(jī)理[J];廣州化工;2015年17期
2 ;Gas sensing performance of polyaniline/ZnO organic-inorganic hybrids for detecting VOCs at low temperature[J];Journal of Natural Gas Chemistry;2011年05期
3 許新華;姜?jiǎng)偬?劉新友;張國(guó)平;;酚與4,4′-聯(lián)吡啶π-π疊加作用的核磁氫譜研究[J];湖南大學(xué)學(xué)報(bào)(自然科學(xué)版);2007年06期
，本文編號(hào)：2248969
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