固相反应法制备磷钼酸(H3PMo12O40)掺杂聚苯胺对其电化学活性的影响

利用固相反应法制备了磷钼酸(H3PMo12O40,简称PMA)掺杂聚苯胺,并以红外光谱(FT-IR)、X-射线衍射(XRD)、循环伏安(cyclic voltamm ogram)等测试方法对聚苯胺进行了表征。结果表明,无论是液相法还是固相法,磷钼酸掺杂于聚苯胺中,仍保持自身结构特征,与传统液相合成的磷钼酸掺杂聚苯胺相比,固相反应法合成的磷钼酸掺杂聚苯胺的晶化率和电活性略差。固相反应法制备的磷钼酸掺杂聚苯胺在对抗坏血酸(AH2)电催化氧化中,表现出比液相合成更好的电催化活性。     

不同掺杂酸对纤维聚苯胺电化学性能的影响

采用界面聚合法通过不同质子酸掺杂分别制备了平均直径约为50,62,95nm的纤维聚苯胺。通过傅里叶变换红外光谱(FT-IR)、扫描电子显微镜(SEM)、透射电镜(TEM)对其化学组成和微观形貌进行了表征,采用循环伏安、恒流充放电和交流阻抗研究了不同质子酸掺杂纤维聚苯胺的超级电容器电容行为,并利用X射线衍射(XRD)、氮气吸脱附及X射线光电子能谱(XPS)等方法对纤维聚苯胺的微观结构进行了深入研究。结果表明:高氯酸(HClO4)掺杂制备的聚苯胺在0.5A/g电流密度下的比容量可以达到397F/g,高于盐酸(HCl,334F/g)和樟脑磺酸(HCSA,383F/g)掺杂聚苯胺的测试结果,纤维的电化学性能主要受其规整度、孔隙率及掺杂度的影响。     

固相反应法制备樟脑磺酸掺杂聚苯胺

固相合成;固相反应法制备樟脑磺酸掺杂聚苯胺     

低温合成樟脑磺酸掺杂聚苯胺微管的电化学电容行为

在低温条件下合成了长约为2-3 μm, 外径约为300-400 nm 的樟脑磺酸掺杂聚苯胺微管. 扫描电镜(SEM)和透射电镜(TEM)显示, 生成的聚苯胺微管管径受樟脑磺酸浓度的影响, 高浓度的掺杂剂有利于管状聚苯胺的形成. 采用交流阻抗、循环伏安、恒流充放电等测试技术对不同产物的电化学电容行为进行了研究, 结果表明, 苯胺单体与樟脑磺酸的摩尔比为1:1时所得掺杂态聚苯胺电极具有较好的循环稳定性, 单电极比电容达到522 F·g-1.     

β-萘磺酸掺杂聚苯胺纳米粒子的固相反应法制备及其表征

利用固相反应法制备了 β 萘磺酸掺杂的聚苯胺纳米粒子 ,并以红外光谱 (FTIR) ,扫描电子显微镜(SEM) ,透射电镜 (TEM) ,X 射线衍射 (XRD)以及粉末微电极等测试方法对其进行了表征 .结果表明 ,固相反应法合成的 β 萘磺酸掺杂聚苯胺粒子直径为 30～ 5 0nm ,聚苯胺分子链排列有序 ,晶化率较好 .粉末微电极的循环伏安测试表明 ,β 萘磺酸掺杂聚苯胺有较好的电化学活性 .     

盐酸掺杂制备导电性聚苯胺的工艺优化研究

掺杂是获得高导电性聚苯胺的重要手段.本文采用盐酸进行掺杂,通过实验研究了不同条件下盐酸掺杂对聚苯胺基本性能的影响,优化了制备聚苯胺的工艺条件.当过硫酸铵与苯胺比为1时,聚合产率高达66.14%;当盐酸浓度为1.5mol/L时,室温下反应12h导电性最好.制备了聚苯胺样品,并对样品进行了FT-IR、SEM、XRD测试.结果均表明盐酸掺杂聚苯胺的反应主要发生在醌环上,掺杂后聚苯胺有一定的结晶性,且呈微纳米颗粒状、分布均匀,电导率达到1.29S·cm~(-1).正交试验得出的优化工艺为:盐酸浓度为1.0mol·L~(-1),氧化剂与苯胺单体摩尔比为1∶1,室温条件下反应4h.     

蒙脱土基氮掺杂多孔碳@聚苯胺复合材料的制备及电化学性能

分别在盐酸和樟脑磺酸-盐酸混酸溶液中,在蒙脱土基新型氮掺杂多孔碳表面原位聚合苯胺,以制备氮掺杂多孔碳@聚苯胺复合电极材料,采用红外光谱(FTIR)、X射线衍射(XRD)和扫描电子显微镜(SEM)表征复合材料的组成和形貌。 盐酸掺杂的复合材料呈短棒状形貌,樟脑磺酸-盐酸掺杂材料形貌呈颗粒状及交联片状,樟脑磺酸-盐酸掺杂的结晶性能优于盐酸掺杂。 电化学测试结果表明,樟脑磺酸-盐酸掺杂的复合材料在0.5 A/g电流密度下的质量比电容为412.5 F/g,比盐酸掺杂的(332.4 F/g)高24.1%,等效串联电阻(R_s)和电荷迁移电阻(R_ct)小;但盐酸掺杂的复合材料在大电流下电容保持率为81.4%,高于混酸掺杂的58.4%。     

新型质子酸掺杂聚苯胺的合成及其电化学电容行为

用化学氧化聚合法制得了草酸掺杂聚苯胺(H2C2O4-PANI)和柠檬酸掺杂聚苯胺(C6H8O7-PANI),并与盐酸掺杂聚苯胺(HCl-PANI)做了对比研究.用红外光谱(FT-IR)、X射线衍射(XRD)和透射电镜(TEM)对掺杂聚苯胺的结构和形貌进行了表征.用循环伏安,恒流充放电和交流阻抗测试对材料在1 mol/L HCl溶液中的电化学电容行为进行了研究.结果表明:3种酸掺杂的聚苯胺具有不同的空间结构,电化学性能也有差异.与盐酸和柠檬酸掺杂的聚苯胺相比,草酸掺杂制备的聚苯胺表现出更优良的电化学电容行为,单电极比电容可达670 F/g.     

聚苯胺/顺丁橡胶复合导电膜的制备与性能(Ⅱ)

采用再掺杂方法制得了樟脑磺酸掺杂的聚苯胺(PAn-CSA),用溶液共混法制备PAn／BR导电复合膜．研究了聚苯胺与顺丁橡胶(BR)复合膜在间甲酚二次掺杂前后电导率的变化。实验表明:CSA对聚苯胺有较好的掺杂作用;二次掺杂使PAn复合膜电导率明显提高,其导电渗滤阈值略有降低,使卷曲的二次掺杂PAn链展开并通过分子链间的相互作用而自行组成导电通路．     

盐酸掺杂聚苯胺的制备及性能研究

本文用溶液聚合法制备盐酸掺杂聚苯胺,测定了体系酸度对聚苯胺电导率的影响,及盐酸掺杂聚苯胺在不同条件下经过热处理后的电导率,采用TGA、XRD等方法,研究了热处理过程对聚苯胺结构的影响。结果表明,当热处理温度为90℃时,电导率高于初始值,当热处理温度高于100℃时,电导率开始下降,到达220℃时,电导率下降了约4个数量级。在氮气中聚苯胺电导率的衰减比空气中小,聚苯胺经热处理后在浓硫酸中的溶解性会明显降低。本文还探讨了去掺杂、氧化和化学交联等盐酸掺杂聚苯胺的热降解机理。     

Dielectric properties of conducting polyaniline films by THz time-domain spectroscopy

The dielectric function of composite polyaniline (PANI)/polyurethane (PU) is studied in the terahertz range. Different free-standing films of composite PANI-CSA/PU with different PANI concentrations are measured by terahertz time-domain spectroscopy (THz-TDS). The Fourier transmission spectrum, the permittivity and conductivity are then precisely obtained between 0.1 and 4 THz. The behaviour of the dielectric function does not follow Drude theory and the extracted data are well fitted by Jonscher’s universal dielectric response. Furthermore, the percolation threshold is also deduced from the insulating to conducting transition extracted for several doping level at very high frequency.     

Preparation of highly conductive, self-assembled gold/polyaniline nanocables and polyaniline nanotubes

One-dimensional gold/polyaniline (Au/PANI-CSA) coaxial nanocables with an average diameter of 50-60 nm and lengths of more than 1 mum were successfully synthesized by reacting aniline monomer with chlorauric acid (HAuCl(4)) through a self-assembly process in the presence of D-camphor-10-sulfonic acid (CSA), which acts as both a dopant and surfactant. It was found that the formation probability and the size of the Au/PANI-CSA nanocables depends on the molar ratio of aniline to HAuCl(4) and the concentration of CSA, respectively. A synergistic growth mechanism was proposed to interpret the formation of the Au/PANI-CSA nanocables. The directly measured conductivity of a single gold/polyaniline nanocable was found to be high (approximately 77.2 S cm(-1)). Hollow PANI-CSA nanotubes, with an average diameter of 50-60 nm, were also obtained successfully by dissolving the Au nanowire core of the Au/PANI-CSA nanocables.     

Comparative studies of solid‐state synthesized poly(o‐methoxyaniline) and poly (o‐toluidine)

Poly(o‐methoxyaniline) (POMA) and poly(o‐toluidine) (POT) salts doped with different acids (methanesulphonic acid (MeSA), trifluoroacetic acid (TFA), and hydrochloric acid (HCl)) were synthesized by using solid‐state polymerization method. The polymers were characterized by Fourier transform infrared (FTIR) spectra, ultraviolet–visible (UV–Vis) spectrometry, X‐ray diffraction (XRD), cyclic voltammetry (CV), and conductivity measurements. Transmission electron microscopy (TEM) was done to study the morphologies of POMA and POT salts. The FTIR and UV‐Vis absorption spectra revealed that the reduced phase was predominant in POMA salts, and the pernigraniline phase was predominant in POT salts. It was found that POMA salts displayed higher doping level and conductivity. In contrast, POT salts were lower at doping levels and conductivity. In accordance with these results, the electrochemical activity was also found to be lower in POT salts. The XRD patterns showed that the POMA salts displayed higher crystallinity than POT salts. The results from TEM revealed that the morphologies of POMA salts were different from those of POT salts. Copyright © 2008 John Wiley & Sons, Ltd.     

In-situ Apparent Mobility of Charge Carriers in Polyaniline Films Measured with a New Four-band Electrode

The in‐situ apparent mobility in polyaniline films was accurately measured in a wide doping region using a new four‐band electrode. It was found the apparent mobility in polyaniline films rises with increasing the doping level or carrier density. The influence of film thickness on the conductivity and apparent mobility of charge carriers was also investigated. The relative higher conductivity observed in a thinner film under low and intermediate doping potentials is assigned to the higher inter‐chain mobility related to the more ordered structure of the film. The mobility variations provide experimental evidence to confirm the inter‐chain path for hopping transport of polarons and the intra‐chain path for evolution of metallic conduction.     

PHOTO-INDUCED DOPED POLYANILINE BY THE VINYLIDENE CHLORIDE AND METHYL ACRYLATE COPOLYMER AS PHOTO ACID GENERATOR

The emeraldine base form of polyaniline (PANI) can be doped by a photo-induceddoping method. In this method a copolymer of vinylidene chloride and methyl acrylate(VCMAC) was used as photo acid generator which can release proton when it is exposedto ultraviolet light (λ= 254 nm). The structure of PANI-VCMAC system before and afterirradiation was characterized by elemental analysis, IR, XPS, and SEM images. Resultsobtained indicate that the photo-induced doping characteristics, such as doping positionand type of charge carriers, are similar to that of PANI doped with HCl. The poor room-temperature conductivity (～10~(-5)S/cm) of PANI-VCMAC system after irradiation maybe due to low doping degree (～pH= 3) and the difference in morphology as compared withPANI-HCl film.     

乳液法制备掺杂聚苯胺的微观结构研究

在众多的导电聚合物中,聚苯胺(PAn)被认为是最具应用前景的导电聚合物^[1].本征态PAn的电导率约10^-13S/cm数量级,呈电绝缘性.当用质子酸对PAn掺杂后,电导率达到5～10S/cm,可实现从绝缘体到导体的转变.     

Research on synthesis and conductivity of ferrocenyl Schiff base and its salt

Ferrocenyl Schiff base was synthesized through the condensation of ferrocenecarboxaldehyde and p‐phenylenediamine under neutral conditions, and then a new interesting category of organometallic charge transfer complex was obtained by the doping of ferrocenyl Schiff base with Fe³⁺, Al³⁺ and Ti³⁺ salts. The effects of the dosage of doping agent and doping temperature on the room‐temperature electric conductivity of samples were discussed; in addition, the temperature dependence of the electric conductivity of samples was studied, their structures and compositions were characterized by ¹H‐NMR spectra, infrared spectra, ultraviolet spectra and an electron probe X‐ray microanalyser. The results showed that the electric conductivity of sample can increase 4–5 orders of magnitude after doping with a metallic salt, and the electric conductivity has a positive temperature coefficient effect. The electrical activation energies of the complexes in the range 0.09–1.54 eV were calculated from Arrhenius plots, indicating their favourable semiconducting behaviour. Copyright © 2006 John Wiley & Sons, Ltd.     

Oxidative polymerization of anilinium 5-sulfosalicylate with peroxydisulfate in water

Anilinium 5-sulfosalicylate was prepared and characterized by elemental analysis, and FTIR and NMR spectroscopies. It was polymerized in an aqueous solution using ammonium peroxydisulfate as an oxidant. The precipitated polyaniline 5-sulfosalicylate exhibited high thermal stability and conductivity of 0.13 S cm⁻¹. Its mass-average molar mass and polydispersity index were determined by gel-permeation chromatography as 22,900 g mol⁻¹ and 2.7, respectively. Elemental analysis and FTIR spectroscopy study of polyaniline 5-sulfosalicylate revealed the doping level and the oxidation state between emeraldine and protoemeraldine salt while corresponding studies of the polyaniline base indicate a small extent of the covalent bonding of 5-sulfosalicylate anions to polyaniline chains.     

Electron Spin Resonanance Studies of Acid-Doped Polyaniline

The electron spin resonance spectra of various acid-doped polyanilines were studied. There are three significant changes in the ESR spectra upon acid-doping as the acid concentration of the doping solution is varied from pH<3 to pH>1: (1) The linewidth decreases by a factor of three. (2) The intensity increases. (3) The spin density increases by a factor of twenty. By comparing the variation of the electric conductivity with the variation of the spin density upon acid-doping, it is proposed that the polyaniline prepared by chemical oxidation consists of various oxidized and reduced units, and that the pi-electron rearrangement upon acid-doping results in highly conductive radical cations.     

PANI/La2O3复合纳米材料的合成及其电化学降解的抑制作用

作为离子型表面活性剂, 对-甲基苯磺酸可用于氧化镧的预超声分散处理, 同时还可作为质子酸对聚苯胺(PANI)进行掺杂, 从而赋予聚苯胺导电性. 采用化学法合成了聚苯胺/氧化镧复合纳米材料, 用四探针法测定了材料的电导率, 用扫描电镜、电子能谱、X射线衍射、红外光谱等检测分析手段对材料进行了表征. 结果表明, 聚苯胺及聚苯胺/氧化镧复合纳米材料的电导率分别为1.0•和1.9 S•cm^－1, 粒子直径分别约为200和50 nm. 氧化镧的掺杂未降低聚苯胺的电导率, 并使粒径减小. 循环伏安实验结果说明, 氧化镧的掺杂可提高氧化还原峰的电流密度, 并能有效抑制聚苯胺在0.25～2.0 mol•L^－1的H₂SO₄及H₃PO₄水溶液中的电化学降解.