不同状态下聚吡咯膜的电化学阻抗

用恒电流法分别聚合了掺杂对甲苯磺酸根(pTS-)和十二烷基磺酸根(DS-)的聚吡咯膜(PPy/pTS和PPy/DS),通过循环伏安法(CV)和电化学阻抗法(EIS)测试了聚吡咯膜在NaCl溶液中‘过电位’电化学过程前后及不同电位下聚吡咯膜的电化学性能.同时,通过嵌入和脱出Na+和Cl-离子的聚吡咯膜在特定溶液中电化学阻抗图谱,研究了离子的嵌入对聚吡咯膜电化学性能的影响.结果表明‘过电位’现象可以提高聚吡咯膜的离子电导率和膜电容,Cl-离子的嵌入能提高PPy/pTS的电导率,而Na+离子的嵌入对聚吡咯膜的电导率影响不大.另外,嵌入离子对聚吡咯膜形貌的改变会对聚吡咯膜的离子传导率有一定影响,从而导致膜的电化学阻抗的变化.     

掺杂离子对聚吡咯膜的电化学容量性能的影响

用电化学方法制备了分别以对甲基苯磺酸根(TOS-), 高氯酸根(ClO-4)和氯离子(Cl-)掺杂的聚吡咯(PPy)膜. 用循环伏安(CV)、恒电流充放电和电化学阻抗谱(EIS)等测试了它们的电化学容量性能. 用扫描电镜(SEM)和X射线衍射(XRD)分别研究了这三种PPy膜的形貌和结构. 研究发现, 由于具有疏松多孔的形貌和更有序的分子链结构, PPy-TOS和 PPy-Cl膜具有较好的充放电能力, 在深度充放电时仍具有很小的电化学电阻, 其离子扩散接近理想电容器的离子扩散机理. PPy-Cl(聚合电量2 mAh·cm-2)的比容量在扫描速率为5 mV·s-1时高达270 F·g-1, 扫描速率200 mV·s-1时仍高达175 F·g-1, 特别是, 其比能量高达35.3 mWh·g-1. PPy-TOS由于有质量较大的掺杂离子(TOS-)因而比容量略低(146 F·g-1, 扫描速率5 mV·s-1), 但具有超快速充放电能力, 在扫描速率为200 mV·s-1时, 比容量为123.6 F·g-1, 其比功率高达10 W·g-1. 并且, 两种电极材料均具有稳定的电化学循环性能.     

多功能性聚吡咯复合膜

聚吡咯具有较高的电导率与良好的环境稳定性,被视为继聚苯胺之后最有工业化应用前景的导电高分子材料之一。聚吡咯与常规聚合物基体如聚乙烯醇、聚氯乙烯等形成的复合膜不仅可以综合聚吡咯奇异的多功能性与常规聚合物的易成膜性和低成本性于一体,而且可望发挥两者的协同效应,从而大大拓宽其应用领域。该研究已经成为导电聚合物研究领域中的又一新热点。作者系统论述了制备这类功能复合膜的两种典型制备方法,并在分析各自特点的基础上提出了改进与发展方向,指出聚吡咯复合膜具有广泛可调的电导率、快速的电学响应性以及稳定的电致变色性等多种功能,在透明导电膜、化学传感器、生物分离膜、电致变色膜领域具有诱人的应用前景。     

Electrochemical Synthesis of Polypyrrole Nanowires

Through a hole in a poly(ethyl acrylate) (PEA) layer that is electrochemically grafted to the surface of a vitreous carbon electrode–that is the route that must be taken by a growing polypyrrole nanowire in the electropolymerization of pyrrole. Chain growth is controlled by diffusion of the monomer through the DMF-swollen PEA layer, which acts as a template for the formation of nanowires (shown in the picture) with diameters of 400–1000 nm and lengths of up to 300 μm.     

Electrochemical Preparation of Polypyrrole/Graphene Films on Titanium Mesh as Active Materials for Supercapacitors

Films of polypyrrole/graphene on titanium mesh were prepared by electrochemical reduction of the fresh dried foam films of graphene oxide followed by an electrochemical polymerization of pyrrole. The as-obtained composite had highly surface area, conductivity, and could be used as the electrode for supercapacitors, especially directly used as the active materials in free of binders while the Ti mesh worked as the collector. Plenty of polypyrrole nanoparticles formed on the surface of reduced graphene film, and some fiber-like aggregates could be formed during the polymerization, which worked as the material for pseudo-capacitance. The specific capacitance of the supercapacitor reached 400 F/g and showed high stability with retaining capacitance of 82% after 5000 cycles, indicating that the nanocomposite is a suitable active material for supercapacitors.     

Polypyrrole Grafts Synthesized via Electrochemical Polymerization

Abstract

Electrically conducting polypyrrole grafts with poly[(methyl meth-acrylate)-co-(2-(N-pyrrolyl) ethyl methacrylate)] (PMMA-co-PEMA) were synthesized by constant potential electrolysis. Cyclic Voltammetry, DSC, TGA, SEM and elemental analysis were used in order to characterize the free standing films. Conductivities of the polymers were measured by a four-probe technique.     

Chemical Reactivity of Polypyrrole and Its Relevance to Polypyrrole Based Electrochemical Sensors

One of the most frequently used conducting polymers, polypyrrole, can take part in chemical processes with typical components of ambient media: oxygen, acids, bases, redox reactants, water, and organic vapors; it can also incorporate nonreactive ions and surfactants from solutions. The influence of such processes on changes of the polymer structure, composition and on possible degradation is analyzed. The benefits and disadvantages of such processes for analytical characteristic of polypyrrole based electrochemical sensors are considered. This discussion is focused on potentiometric ion sensors, where polypyrrole is either a receptor membrane or an ion‐to‐electron transducer placed between a solid state electrode support and a typical ion‐selective membrane.     

聚吡咯薄膜的电特性

含有不同的链长的w-吡咯烷基二甲基氯硅烷作为粘合剂通过自组装（SAMs）吸附于二氧化硅表面,然后聚吡咯膜化学沉积于该粘合剂修饰的表面。化学沉积的聚吡咯膜的表面形貌用扫描电镜（SEM）及原子力显微镜（AFM）表征。除短链外不同链长的粘合剂对聚吡咯膜的厚度影响不大。聚吡咯膜的电特性用电流-电压表征。结果显示电流与粘合剂的链长无关。电特性表明载流子迁移率为1.4 ´ 10-4 cm2×V-1.s –1。     

The Electrochemical Behavior of Polypyrrole under Ultrasound

Polypyrrole (PPy) is one of the most important conducting polymers. It has been widely studied for the uses of chemical sensors, electrocatalysis, rechargeable batteries and protective layers on semiconductor electrodes^[1].     

聚吡咯改性电沉积Sn负极材料的电化学性能

本工作采用直接在铜箔表面恒电流电沉积的方法制备Sn负极,以NiCl₂为沉积电解液的添加剂得到了Sn空心管,提高了单纯Sn负极的可逆比容量,60次循环后仍剩余184.3 mAh·g^-1。进一步引入聚吡咯进行表面修饰改性,有效地提高了沉积电极的电化学循环性能,60次循环后仍剩余440.6 mAh·g^-1可逆比容量,同时具备良好的循环稳定性。沉积电极可直接用作锂离子电池负极,无需任何粘结剂,电极装配操作简单。     

多次聚合法制备多孔聚吡咯厚膜及其电化学容量性能

为了得到高面积比容量的聚吡咯(PPy)膜超级电容器电极材料, 用多次聚合法合成了PPy厚膜, 聚合电量分别为8、10和12 mAh·cm-2, 掺杂离子分别为氯离子和对甲基苯磺酸根离子(TOS-). PPy膜的电化学性能采用恒电流充放电、循环伏安(CV)和电化学阻抗谱(EIS)等方法测试. 研究表明, 多次聚合法可以制备表面平整且内部均匀多孔的PPy厚膜. 在聚合电量为12 mAh·cm-2时, 用Cl-、TOS-两种离子掺杂的PPy厚膜的面积比容量高达5 F·cm-2, 并表现出理想的电化学容量性能. 同时PPy-Cl厚膜的质量比容量达到330 F·g-1, PPy-TOS厚膜的质量比容量略低(191 F·g-1), 但具有更快的充放电速率. 与一次聚合法合成的PPy 薄膜相比, 多次聚合法合成的PPy厚膜的质量比容量没有降低. 通过场发射扫描电镜(SEM)观察了一次聚合法和多次聚合法制备的PPy厚膜的截面形貌, 并讨论了多次聚合法的合成机理.     

以膨胀石墨为基底的聚吡咯电化学免疫传感器

用恒电位法在膨胀石墨基底表面合成聚吡咯,聚吡咯上的亚氨基与戊二醛发生交联,制备成稳定的膨胀石墨/聚吡咯/戊二醛传感器界面.以此界面固定人IgG抗体,戊二醛作为交联剂,发展了一种新型的电化学免疫传感器.该传感器在IgG溶液中温育后,其表面结合的IgG和随后加入的辣根过氧化氢酶(HRP)标IgG二抗以及传感器表面的IgG抗...     

Study of the Properties of Electrodeposited Polypyrrole Films

Experimental and theoretical methods have been used for characterization of the properties of polypyrrole films. The AFM studies show that the morphology of polypyrrole (PPy) films on polycrystalline gold electrodes at the first stages of synthesis depends on the structure of the metal surface. It was established that mobility of anions depends remarkably on the rate of electrodeposition of the polymer film. If PPy film was deposited at relatively low current density, mobility of ClO^- ₄ anion was not high enough to guarantee electroneutrality during redox cycling and cations take part in this process especially when Li⁺ cations were replaced by more mobile ⁺ cations. Semiempirical (AM1 and PM3) quantum-chemical methods were used for theoretical studies. It was established that different size and charge of the anions together with the variation in doping levels give rise to a different optimal conformation of oligopyrrole cations which, in turn, define the resulting polymer to be either all-anti (common linear chains) or all-syn (formation of helical structures) or a combination of the two.     

聚吡咯改性电沉积Sn负极材料的电化学性能

本工作采用直接在铜箔表面恒电流电沉积的方法制备Sn负极,以NiCl2为沉积电解液的添加剂得到了Sn空心管,提高了单纯Sn负极的可逆比容量,60次循环后仍剩余184.3 mAh·g-1。进一步引入聚吡咯进行表面修饰改性,有效地提高了沉积电极的电化学循环性能,60次循环后仍剩余440.6 mAh·g-1可逆比容量,同时具备良好的循环稳定性。沉积电极可直接用作锂离子电池负极,无需任何粘结剂,电极装配操作简单。     

分段控温原位聚合沉积法制备苯胺-邻苯二胺共聚物薄膜

提出在玻璃基体表面原位聚合沉积制备苯胺-邻苯二胺(An-oPD)共聚物薄膜的一种方法:分段控温法,即高温预聚(高水浴温度)、低温聚合(冰水浴)。该法可在缩短聚合反应时间的同时避免暴聚现象,提高成膜效率,所得共聚物薄膜形貌特征优异、膜厚均匀;该法可制得饱和厚度120 nm,电导率9.16×10-2S/cm的An-oPD共聚物薄膜,具有与均聚PAn薄膜不同的电致变色性能。     

Electrochemical Synthesis and Characterization of Electroactive Conducting Polypyrrole Polymers

Conducting/electroactive polypyrrole polymers are synthesized electrochemically on glassy carbon in various electrolytes (counterions). The polymers' electroactivity is measured using cyclic voltammetry. The electrolytes are chloride, nitrate, p-toluene sulfonate, dodecyl sulfate, and dodecylbenzenesulfonate of sodium and potassium ferrocyanide. It is found that the electrolyte (dopant) markedly affects the redox behavior of the polypyrrole films.     

聚吡咯的合成与新型双离子电池性能研究

用反相微乳聚合法制备了十二苯磺酸(DBSA)掺杂的导电聚吡咯纳米材料, DBSA既作为表面活性剂又作为掺杂剂, 能够提高聚吡咯的导电性. 用制备出的DBSA-PPy 为正极材料, 石墨为负极材料组装双离子电池, 测试结果表明, C/DBSA-PPy 电池的电化学性能已达到传统锂离子电池的水平, 这是因其具有较高的导电性和特殊掺杂结构的聚吡咯使其电化学性能得到优化.     

Synthesis and Electrochemical Characterization of Modified Graphene/Polypyrrole Nanocomposites

Nanocomposites based on both modified/unmodified graphene and polypyrrole, were investigated as electrode materials for supercapacitor application. All the nanocomposites were prepared by in-situ oxidative polymerization method using ammonium persulfate as oxidant. The amine functionalization of Graphene was confirmed by FTIR and X-ray Photo Electron Spectroscopy (XPS). Field Emission Scanning Electron Microscopy (FESEM) and High Resolution Transmission Electron Microscopy (HRTEM) analysis were performed to study the morphology of the nanocomposites. The maximum capacitance value was found as 240 F/g for unmodified graphene based composite. Though the capacitance value was found to be lower for modified graphene based composite, the cyclic stability was found to be higher as compared to unmodified graphene/polypyrrole nanocomposite.