Electrochemical Properties of Polypyrrole-Coated Microelectrode Array and the Fabrication of Polypyrrole-Based Microelectronic Devices

Conducting polymers have been studied extensively. An interesting property of the conducting polymer is that the conductivity of some polymers, such as polypyrrolc, polyaniline, poly(3-methylthiophene) etc. , is affected by the voltage applied to them. For polypyrrole, the oxidized state is an electronic conductor and the reduced state is essentially insulating. Using this property, one can fabricate the polymer-based electronic devices. Experimental results of Pickun

Electrochemical Formation of Polypyrrole-carboxymethylcellulose Conducting Polymer Composite Films

The electrochemical preparation of polypyrrole-carboxymethylcellulose （PPY-CMC） conducting polymer composite films on indium tin oxide （ITO） glass electrode from an aqueous solution containing pyrrole monomer, ptoluenesulfonate electrolyte and carboxymethylcellulose insulating polymer is reported. The characterization by Fourier transform infrared spectroscopy （FT-IR） shows that carboxymethylcellulose （CMC） has been successfully incorporated into polypyrrole structure forming PPY-CMC polymer composite films. The conductivity of the prepared composite films was found to increase with increaseing CMC concentration in pyrrole solution, The optical microscopic results show the influence of CMC concentration in the pyrrole solution over the morphological changes of the prepared films. The dynamic mechanical analysis （DMA） on the prepared PPY-CMC film reveals the higher plastic property of the PPY-CMC composite film.

Polypyrrole-coated styrene-butyl acrylate copolymer composite particles with tunable conductivity

A series of near or monodisperse styrene-butyl acrylate (SBA) copolymer latex particles with different butyl acrylate contents were coated with polypyrrole. The struc- ture of the SBA/PPy composites was characterized by trans- mission electron microscopy (TEM), scanning electron mi- croscopy (SEM), diffuse reflectance infrared Fourier trans- form spectroscopy (DRIFT), X-ray photoelectron spectros- copy (XPS), differential scanning calorimetry (DSC) and standard four-probe method. The core-shell morphology of the SBA/PPy composite particles was confirmed. The result of DSC showed that Tg of the composite is mainly determined by the core component. The effects of the concentration of polypyrrole, the butyl acrylate content in SBA copolymer and the nature of the counter-anion on the electrical conduc- tivity of compression-moulded samples were studied. It was first found that the electrical conductivity of the samples can be tuned by varying the butyl acrylate content in SBA co- polymer and the highest conductivity of the core-shell com- posite was 0.17 S·cm?1.

STUDY ON POLYPYRROLE-VISCOSE CONDUCTING FIBER

The conductivity of Polypyrrole-viscose conducting fiber prepared with author’s method can be shown up to as high as 2.106x10-2 S/cm. The main factors influencing the conductivity are the concentration of FeCl3 used as dopant and initiator, the treatment time of viscose fiber as base material in FeCl3 solution, temperature and polymerization time. It is found that the orientation and crystallization degree of viscose fiber keep constant before and after conducting treatment and the mechanical properties of conducting fiber is the same as that of base material. In addition, the distribution of polypyrrole in viscose fiber, and its effect on the conductivity were investigated in details by TEM.

Polypyrrole Coated PET Fabrics for Thermal Applications

Polypyrrole can be chemically synthesized on PET fabrics, giving rise to textiles with high electric conductivity. These textiles are suitable for several applications from antistatic films to electromagnetic interference shielding devices. Here we discuss the thermal-electric performance and the heat generation of polypyrrole coated PET fabric samples, previously studied because of their electric conductivity and electromagnetic interference shielding effectiveness. The measured Seebeck effect is comparable with that of metallic thermocouples. Since polypyrrole shows extremely low thermal diffusivities regardless of the electrical conductivity, the low thermal conductivity gives significant advantage to the thermoelectric figure-of-merit ZT, comparable with that of some traditional inorganic thermoelectric materials. The heat generation is also investigated for possible heating textile devices. The results confirm polypyrrole as a prom- ising material for thermal electric applications due to its easy preparation in low cost processing.

Fabrication and Mechano-sensing Characteristics of Bending Polypyrrole Actuator

To prepare a conductive polymer actuator with decent performance,a self-built experimental platform for the preparation of polypyrrole film is employed.One of the essential goals is to examine the mechanical characteristics of the actuator in the presence of various combinations of process parameters,combined with the orthogonal test method of"four factors and three levels".The bending and sensing characteristics of actuators of various sizes are methodically examined using a self-made bending polypyrrole actuator.The functional relationship between the bending displacement and the output voltage signal is established by studying the characteristics of the actuator sensor subjected to various degrees of bending.The experimental results reveal that the bending displacement of the actuator tip almost exhibits a linear variation as a function of length and width.When the voltage reaches 0.8 V,the bending speed of the actuator tends to be stable.Finally,the mechanical properties of the self-assembled polypyrrole actuator are verified by the design and fabrication of the microgripper.

The Gas Sensitivity of Polypyrrole Film Fabricated by in Situ Polymerization

1 Results Polypyrrole (PPy) is a typical conducting polymer with high conductivity and good stability,and has been widely used for detection of gases including ammonia and nitroxide[1].However the reversiblity and selectivity of the response to these gases are always not satisfying.In the paper,conductive PPy film was deposited on the interdigital electrode modified by one bilayer of poly(diallyldimethylammonium chloride) and poly(sodium styrenesulfonate),by in-situ polymerization with FeCl3 as oxidizin...

Polypyrrole as an ultrafast organic cathode for dual-ion batteries

Organic electrode materials based on the chemical bond cleavage/recombination working principle usually produce unimpressive reaction kinetics and stability.In this work,polypyrrole(PPy)is investigated as an ultrafast(87%retention at 20 A g^(-1))and stable(83%retention across 3000 cycles)cathode material in PPy|graphite dualion batteries.The fast intrinsic reaction kinetics,coupled with a capacitance-dominated mechanism,enable PPy to bypass the sluggish chemical bond rearrangement process.Electrochemically induced secondary doping improves the ordered aggregation of polymer chains and thus has a profound impact on anion diffusion and electrical conductivity.The excellent rate capability presented here changes our understanding of organic electrode materials and could prove useful for designing ultrafast rechargeable electrochemical devices.

INFRARED EMISSIVITY OF CONDUCTING POLYMERS

The infrared emissivity of conducting polymers in 8—20μm and at 50—150℃ in the direction of normal line has been measured as a function of wavelength, conductivity at room temperature, counterion, doping levels, measuring temperature and thickness of sample.

Study on the High Conductive Polymer as the Miniaturized Reference Electrode

The polypyrrole is the high conductive polymer which was coated onto indium tin oxide (ITO) glass substrate by electroplated technique to fabricate a miniaturized reference electrode.Besides,the morphology of the ITO glass reference electrode electroplated with pyrrole has been studied through the instrumental analysis utilizing cyclic voltammetry (CV). Furthermore,the sensing characteristics of the reference electrode have been measured by using commercial instrumental amplifier as the readout circuit.Using the high conductive polymer as miniaturized reference electrode has many advantages such as easy fabrication of coating polymer,without any expensive fabricating equipment,easy carry by the miniaturized technique.Hence,it is suitable for the reference electrode production.

Highly Sensitive Functionalized Conducting Copolypyrrole Film for DNA Sensing and Protein-resistant

In order to exploit the applications ofpolypyrrole （PPy） derivatives in biosensors and bioelectronics, the different immobilization mechanisms of biomolecules onto differently functionalized conducting PPy films are investigated. Pyrrole and pyrrole derivatives with carboxyl and amino groups were copolymerized with ω-（N-pyrrolyl）-octylthiol self-assembled on Au surface by the method of the chemical polymerization to form a layer of the copolymer film, i.e., poly[pyrrole-co-（N-pyrrolyl）-caproic acid] （poly（Py-co-PyCA）） and poly[pyrrole-co-（N-pyrrolyl）-hexylamine] （poly（Py-co-PyHA））, in which the carboxyl groups in poly（Py-co-PyCA） were activated to the ester groups. Based on the structure characteristics, the immobilization/hybridization of DNA molecules on PPy, poly（Py-co-PyCA） and poly（Py-co-PyHA） were surveyed by cyclic voltammograms measurements. For differently functionalized copolymers, the immobilization mechanisms of DNA are various. Besides the electrochemical properties of the composite electrodes of PPy and its copolymers being detected before and after bovine serum albumin （BSA） adsorption, the kinetic process of protein binding was determined by surface plasmon resonance of spectroscopy. Since few BSA molecules could anchor onto the PPy and its copolymers surfaces, it suggests this kind of conducting polymers can be applied as the protein-resistant material.

Wafer-scale quasi-layered tungstate-doped polypyrrole film with high volumetric capacitance

Layered materials are particularly attractive for supercapacitors because of their unique physical,electrical and chemical properties.Here,we demonstrate a facile and scalable electrochemical deposition method for wafer-scale synthesis of quasilayered tungstate-doped polypyrrole films(named TALPy)with controllable thickness and size.The as-prepared TALPy film exhibits a high gravimetric density and excellent volumetric capacitance,exceeding many high-performing carbon-and polymerbased film electrodes.Based on combined results of ex-situ X-ray diffraction(XRD),Raman and X-ray photoelectron spectroscopy(XPS),it is determined that TALPy stores charge through an ion intercalation process accompanied by change in oxidation states of polypyrrole backbone,which is referred as intercalation pseudocapacitance.All these results suggest the great promise of electrochemical deposition as a scalable and controllable bottom-up approach for synthesizing quasi-layered conductive organic-inorganic hybrid films for electrochemical energy storage applications with high volumetric performance.

Electrochemical behaviors of novel composite polymer electrolytes for lithium batteries

A novel composite polymer electrolyte was prepared by blending an appropriateamount of LiClO_4 and 10 percent (mass fraction) fumed SiO_2 with the block copolymer of poly(ethylene oxide) (PEO) synthesized by poly (ethylene glycol) (PEG) 400 and CH_2C1_2 The ionicconductivity, electrochemical stability, interfacial characteristic and thermal behavior of thecomposite polymer electrolyte were studied by the measurements of AC impedance spectroscopy, linearsweep voltammetry and differential scanning calorimetry (DSC), respectively. The glass transitiontemperature acts as a function of salt concentration, which increases with the LiClO_4 content.Lewis acid-base model interaction mechanism was introduced to interpret the interactive relationbetween the filled fumed SiO_2 and the lithium salt in the composite polymer electrolyte. Over thesalt concentration range and the measured temperature, the maximum ionic conductivity of thecomposite polymer electrolyte (10^(-4.41) S/cm) appeared at EO/Li=25 (mole ratio) and 30 deg C, andthe beginning oxidative degradation potential versus Li beyond 5 V.

Conductive core/shell polymer nanofibres as anode materials for direct ethanol fuel cells

A conductive polymer-supported electrocatalyst in the form of fibrous mat has been developed that can be employed as a polymer-based electrode for direct ethanol fuel cells(DEFCs)with promoting effects to the state-ofthe art Pd based catalysts.A series of conductive polyaniline(PANI)-containing polymer fibres-supported Pd electrocatalytic electrodes were successfully prepared and tested for the ethanol electro-oxidation reaction(EOR)in alkaline medium.The polymer support was a robust fibrous mat,where the fibres possessed a core-shell configuration.The core part was produced via electrospinning using a mixture of polyacrylonitrile(PAN)and 1-butyl-3-methylimidazolium chloride[BMIm]Cl ionic liquid(IL).The shell was a PANI layer deposited via the chemical polymerisation of aniline monomer.Pd was then electrodeposited on the fibres and the catalysts were tested for the EOR via cyclic voltammetry(CV)in a half-cell configuration and in a temperature range between 25 and 60C.The activity of the catalysts tested was measured in terms of activation energy and forward peak current density in the CV and compared to that of glassy carbon(GC)-supported Pd/PANI/PAN/IL fibrous catalysts.The polymer fibre-catalyst samples showed a higher active surface area and significantly lower activation energy than the GC-based ones.Even though the GC-supported catalysts showed a higher activity in terms of current,the Pd/(PAN/IL)-core/PANI-shell fibrous mats were active as well and,in some cases,demonstrated a promoting effect of PANI on Pd for EOR and a much better stability and robustness compared to the former.Furthermore,a series of promoting metals were investigated for these mats,such as Ag,Bi and Cu,with Ag and Bi demonstrating promoting effects compared to monometallic Pd/(PAN/IL)-core/PANI-shell mats in terms of both activation energy and peak current density.This work demonstrates a promising strategy in the arena of development of polymeric mats as anode electrodes for DEFCs,exploiting the benefits of PANI in terms of ease of synthesis,catalyst poisoning prevention,cost and promoting effects.

氮化硼负载BT@PANI核壳粒子协同改善复合材料介电与导热性能

采用原位聚合法对氮化硼纳米片(BNNS)进行了聚多巴胺(PDA)的表面修饰,利用PDA的粘附性在BNNS表面负载钛酸钡@聚苯胺(BT@PANI)核壳粒子制备了分级结构复合填料。结果显示,BNNS单片的BT@PANI负载量对复合材料介电和导热性能影响显著;与BT@PANI/PVDF复合材料比较,所得复合材料的介电性能随频率变化的稳定性得到明显改善。BNNS单片BT@PANI负载量最大的复合材料界面极化最弱,介电性能表现出更好的频率稳定性,20%(质量分数)的复合材料介电常数和损耗值分别是14.8和0.082(10^(5)Hz),热导率降到了最低的0.64 W/mK。频率高于10^(3)Hz,这种新型复合材料介电损耗下降幅度是介电常数的2倍以上。该工作同步实现了聚合物基复合材料的介电常数提高、介电损耗抑制及导热性能提升,为储能聚合物基复合电介质的发展提供了新思路。

锂离子电池硅基负极用功能粘结剂的研究进展

硅(Si)具有超高的理论比容量、较低的嵌锂电位及丰富的储量等优势,是发展高比能锂离子电池的关键负极材料。同纳米Si相比,低成本、高振实密度和低界面反应的微米Si应用于高体积能量密度器件独具优势。然而其300%体积形变产生的巨大应力,使得颗粒破碎粉化、电极结构退化以及导电网络失效等问题更为严峻,极大制约了其商业化进程。粘结剂是适应Si体积变化,提供稳定导电网络的重要手段。开发高容量、高稳定微米Si基负极对粘结体系设计提出了更大的挑战。本文首先阐明了粘结剂的基础功能与粘结机制,然后从自愈合、电子导电、离子导电以及参与固态电解质层构建四个方面,总结了Si基负极用功能粘结剂的设计策略和作用原理,最后展望了面向实用化的Si基负极功能粘结剂面临的挑战和未来发展方向。

聚吡咯在电化学中的应用研究进展

介绍了导电聚合物聚吡咯的主要制备方法及其在电化学中的应用进展,并分析了存在的问题,最后对未来的研究方向进行了展望。

填充型聚合物基导热复合膜的研究进展

随着柔性电子器件的飞速发展和应用,传统的热管理材料无法满足高导热、高韧性、良好机械适应性的应用需求。具有高导热系数的柔性导热薄膜材料在下一代器件的热管理应用中显示出巨大的潜力,因此引起了广大学者的关注。目前,导热薄膜材料在智能手机、超薄笔记本、柔性可穿戴设备和智能家电设备中均展现巨大的应用潜能。本文从提升填充型导热复合膜的导热性能出发,介绍了填充型导热复合膜的分类和填充型导热复合膜的导热机理。由设计填料构筑低热阻高导热通路和构筑三维导热网络两种思路提升复合膜的导热性能,阐明了填充型导热复合薄膜的研究进展。