聚吡咯薄膜中茜素红S的电化学特性

利用循环伏安法研究了聚合电位和聚合电量对茜素红S掺杂聚吡咯薄膜修饰玻碳电极性质的影响,考察了不同电位范围内修饰电极的电化学特性.发现在茜素红S的氧化还原过程中存在着茜素红S分子与聚吡咯链的相互作用,且这一相互作用敏感于扫描正电位限.基于实验结果,提出了可能的茜素红S在电极表面聚吡咯膜内的氧化还原机理.     

聚吡咯膜的电氧化形成和伏安特性

本文对铂电极上聚吡咯膜电氧化形成进行了探讨。获得了均匀、有透明感并显现电钯特性的聚吡咯膜。新生成的聚吡咯膜在一些电解液中表现电氧化-还原活性。但长期往复极化后会逐渐退化到高阻的惰性状态。应用聚吡咯膜保护烧结n-CdS光阳极的尝试未取得满意的效果。     

可溶性聚吡咯复合导电薄膜的研制

聚吡咯具有容易合成、导电率较高、稳定性较好等优点,已经对其进行了广泛而深入的研究,并且逐渐向工业应用方向发展^[1].但其不溶不熔性使得难于对其进行分子结构表征和加工.     

导电高分子薄膜修饰电极的研究I. 聚吡咯薄膜电极的电化学合成及行为

利用在水溶液中的电化学聚合制备了聚吡咯烷、薄膜修饰电极. 讨论了对电化聚合的影响因素及薄膜修饰电极在不同电解质中的伏安特性, 从X-射线光电子能谱推测, 在吡咯的电化聚合过程中氧的参加引起在聚吡咯烷膜的结构中有羰基和羟基的生成.     

电聚合导电聚吡咯的合成研究

用电化学法将吡咯单体聚合在电极上，于不同支持电解质的水溶液中得到聚吡啶薄膜。研究了电解质浓度、电解质阴离子种类及聚合时间对聚吡咯薄膜导电性能的影响。     

导电高分子薄膜修饰电极的研究 Ⅰ.聚吡咯薄膜电极的电化学合成及行为

聚吡咯(PPy)是发展较早的一种杂环导电高分子,有关其制备、电化学形为和表征已有文献报道.PPy 不仅具有良好的导电性和较高的稳定性,而且易于制备.利用在电化学聚合过程中可能掺入目的功能团的特点,PPy 作为一种修饰电极对电催化和电分析方面的研究已引起了注意.目前,PPy 的制备主要集中于有机体系,而在水溶液中的研究还较少.本文用电     

磷钼酸掺杂的聚吡咯薄膜电极的表征

对离子在导电聚合物修饰电极中起着很重要的作用．因止匕自从导电聚合物薄膜修饰电极的研究开始以来，A们尝试了在导电聚合物膜中掺杂各种各样的离子［‘一句，以使导电聚合物膜向功能化方向发展．在这些众多的掺杂离子中，人们无感兴趣的是将那些电活性阴离子作对离子掺杂人导电聚合物膜中，如时C叫6【‘，司、杂多酸根离子”河等·将电活性阴离子作为对离子掺杂人导电聚合物膜修饰电极中，有助于人们对这种修饰电极的研究，因为这些对离子可以作为一种探针来检测对离子在腰中的传输情况．杂多酸掺杂的导电聚合物电极还具有电催化性能，对…     

Keggin型磷钼酸-聚吡咯薄膜修饰电极及其电催化特性的研究

本文采用电化学方法在玻碳电极上制备了keggin型磷钼酸(PMo12)-聚吡咯(Ppy)薄膜修饰电极,并探讨了该电极电催化机理。实验结果表明,该电极对水中的溴酸盐具有响应速度快,检测灵敏度高,稳定性好,能实现快速准确测定。BrO-3在0.005~0.1 mmo.lL-1浓度范围内,与修饰电极上的电流响应信号值呈线性关系,检出限为2μmol.L-1。该方法为研制水中溴酸盐的检测仪器提供了理论基础。     

ZnO/eosin-Y混合薄膜的生长机理和形态

Thin hybrid films of ZnO/eosin-Y were prepared by electrodeposition at-0.8 and-0.9 V in aqueous and non-aqueous baths at temperatures ranging from 40 to 90 ℃ with dye concentrations of 100 and 400 μmol·L-1.The films were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM),energy-dispersive X-ray analysis (EDX),and absorption spectroscopy.The films prepared in a non-aqueous bath were non-porous and did not adsorb dye molecules on their surface.However,the films grown in aqueous media were porous in nature and adsorbed dye during the deposition of ZnO.Preferential growth of the film along the (002) face was observed,and the highest crystallinity was achieved when the film was deposited at 60 ℃.The maximum absorption was achieved for the films grown at 60 to 70 ℃,a deposition potential of-0.9 V,and a dye concentration of 100 μmol·L-1.     

聚吡咯薄膜在超临界CO_2与离子液体两相体系中的电化学合成

首次在超临界CO2与离子液体两相体系中实现了聚吡咯（PPyr）薄膜的电化学合成.与纯离子液体相比,该体系中合成的PPyr膜具有均匀平滑的表面.随着CO2压力的增加,膜的生长速度减慢,膜的表面变得更加均匀平滑.     

Bio‐Inspired Dopamine Functionalization of Polypyrrole for Improved Adhesion and Conductivity

We report the functionalization of polypyrrole (PPy) with a “sticky” biomolecule dopamine (DA), which mimics the essential component of mussel adhesive protein. PPy is one of the most promising electrically conductive polymers with good biocompatibility. The research findings reveal that the DA functionalization enhances the dispersibility and stability of PPy in water and its film adhesion to substrate surface significantly. The electrical conductivity of PPy increases to a maximum value and then decreases with the increasing DA concentration. An optimal DA to pyrrole (Py) mole ratio is found to be between 0.1 and 0.2, at which both conductivity and adhesion of DA‐functionalized PPy has been improved.

     

Bifunctional Adhesion Promoter for Grafting Polypyrrole Films on Metal/Metal Oxide Surfaces

A new class of pyrrole derivatives, ω-[(3-phenyl) pyrrol-1-yl] alkyl phosphonic acids with long chains of 10 and 12 carbon atoms were synthesised to graft polypyrrole layers on metal/metal oxide surfaces. These compounds are bifunctional containing two reactive moieties, pyrrole as the polymerisable group and phosphonic acid as the anchoring group. Contact angle measurements and X-ray photoelectron spectroscopy (XPS) confirmed adsorption with phosphonic acid group attached to the surface. Surface plasmon resonance (SPR) spectroscopy indicated that adsorption starts in seconds and is completed in few hours. Adsorption is followed by surface induced polymerisation with further monomer. We obtained dense and homogeneous polypyrrole films, which were characterised for their morphology and thickness by atomic force microscopy (AFM). The derivatives form a strongly bonded composite of metal with polymer.     

水浴法制备CdS薄膜产生的本征缺陷对光电学性质的影响

采用化学水浴沉积法(CBD)在钠钙玻璃衬底上制备硫化镉(CdS)薄膜,研究不同硫酸镉(CdSO_4)浓度下产生的本征缺陷对CdS薄膜光电学性质的影响。采用光致发光光谱、紫外-可见分光光度计及霍尔效应测试系统对薄膜的本征缺陷、光学及电学性质进行分析,发现CdS薄膜主要存在镉间隙(Cdi)及硫空位(VS)等本征缺陷,且VS随CdSO_4浓度的降低而逐渐减少。同时,VS缺陷的减少有利于薄膜透过率的提高,但在一定程度上降低了薄膜的电导率。根据透过率及其相关公式可知,半导体材料中透过率与电导率成e指数反比关系,适当减小薄膜的电导率可以使其透过率得到大幅度的提高,理论解释与实验结果相一致。     

Electrical Properties of Ag Thin Films Deposited by the Improved SILAR Method

Ag films were deposited on glass substrates using the successive layer adsorption and reaction (SILAR) method and characterized with XRD and AFM. The I‐V curves of the thicker Ag films obeyed ohmic law because of the formation of the continuous films. After annealing at 300°C in N₂, the conductance increased due to the removal of imperfections. Compared with the thicker film, the thinner Ag films showed nonlinear I‐V curves. After annealing, these films were inconductible. This may be ascribed to the destruction of the junction, that existed between the Ag islands. The absorption spectra of the films proved the formation of the Ag islands after annealing. With the thickness of the films further decreasing, the Ag films became insulated.     

Electrical and mechanical properties of the zone-drawn polypyrrole films

The zone-drawing method (ZD) was applied to electrochemically synthesized polypyrrole films containing tosylate (PPy/TsO) and the mechanical and electrical properties of the resulting films were investigated. It was found that the electrical conductivity of the zone-drawn film reached 365 S cm⁻¹ in the drawing direction, which was 4.7 times that of the original film. The tensile properties of the zone-drawn film were improved and Young's modulus and strength at break increased to 4.32 GPa and 90.1 MPa from 0.53 GPa and 40.4 MPa of the as-synthesized film, respectively. The dynamic storage modulus (E) increased by the zone-drawing over a whole experimental temperature range and attained 7.0 GPa at room temperature and 4.0 GPa even at 200°C. © 1996 John Wiley & Sons, Inc.     

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.     

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。     

Electrical Properties of Sol-Gel Processed Amorphous BaTiO3 Thin Films

BaTiO₃ thin films were prepared on single crystal silicon (1 0 0) and platinum substrates by sol-gel technique. Amorphous films with thickness uniformity were obtained by spinning the solution at 3000 rpm for 30 s and by post-deposition annealing at 400°C. The films exhibited good dielectric and insulating properties. The dielectric constant and dissipation factor at a frequency of 100 kHz were 17 and 0.20, respectively, for 1400 Å thick film on platinum substrate (MIM). The corresponding values were 16 and 0.015 for films on Si (MIS). Dielectric properties were also studied as functions of frequency and voltage. The C-V curve for MIS structure exhibited a hysteresis. The density of interface states recharged during the bias cycle in hysteresis measurement was estimated to be of the order of 2.10 × 10¹¹ cm^–2 and total oxide charge density was about 4.28 × 10¹¹ cm^–2. I-V measurements were performed on films of different thicknesses. The leakage current densities at 5 V for the films having thicknesses 1400 and 2800 Å were 0.86 and 0.11 A/cm² respectively. The conduction mechanism is found to be Poole-Frenkel and Schottky mechanisms at low and high fields, respectively.     

Synthesis and Characterization of Conductive Polypyrrole/Montmorillonite Nanocomposites via One-pot Emulsion Polymerization

A series of electrically conductive polypyrrole/clay nanocomposites were synthesized in this work by using one-pot emulsion oxidative polymerization of pyrrole in the presence of unmodified clay and using DBSNa as the surfactant. The effect of surfactant on the morphological and electrical properties of PPy also were investigated and discussed in some extent. Electrical conductivity of the samples was measured by using samples in which the conductive materials was sandwiched between two Ni electrodes at room temperature. PPy/MMT nanocomposites were characterized by using XRD, TEM, TGA and DSC means of investigation. Intercalated structures were determined for the nanocomposites as confirmed by XRD and TEM studies. Electrical conductivity of the nanocomposites was measured to be dependent to the clay content, and the methods of preparation. Measurement also showed that polymerization of pyrrole monomers pre-intercalated between the clay gallery spaces of the clay led to higher conductivity for the nanocomposite in the same level of clay content. Thermal property measurements showed a lower thermal decomposition rate for the PPy/MMT nanocomposites with respect to the PPy.