Hybrid organic/inorganic films of conducting polymers modified with phthalocyanines. II. EIS studies and film characterization

Conducting polymers were modified with Cu-phthalocyanine or Co-phthalocyanine embedded in a sol–gel matrix. The resulting films were characterized using electrochemical impedance spectroscopy, Fourier transform infrared spectroscopy and scanning electron microscopy. Electrochemical impedance spectroscopy data showed that the application of the sol–gel layer to the conductive polymer caused a noticeable increase in the impedance of the film across the frequency ranges studied. The hydrophobic character of the film was greatly influenced by the sol–gel and caused an increase in its capacitance. A modified ‘Randles’ equivalent cell was used to correlate the electrochemical parameters of the films. Elemental analysis and infrared data confirmed the presence of the phthalocyanine moieties in the film and the empirical formula of the film was estimated. The surface morphology of the sol–gel-modified conducting polymer was distinctly amorphous compared to the poly(3-methyl thiophene).     

Hybrid organic/inorganic films of conducting polymers modified with phthalocyanines. I—Film preparation and voltammetric studies

Conducting polymers were deposited on the surface of platinum and glassy carbon electrodes. The monomers used were N-methyl pyrrole and 3-methyl thiophene. The electrochemical synthesis of the polymer was achieved using constant applied potential or cyclic polarization techniques in acetonitrile as a solvent and tetra-alkyl ammonium salts as supporting electrolyte. The resulting conducting polymeric film was modified with an inorganic metal complex, namely, Cu–phthalocyanine or Co–phthalocyanine. Two different approaches were adopted for the modification: (1) the first was to directly apply the metal–phthalocyanine layer on the surface of the polymer, and (2) the second was by the inclusion of the metal–phthalocyanine in a sol–gel matrix that was in turn applied to the conducting polymer film. In the first part of this work, we studied the effect of changing the type of polymer matrix and the central metal of the inorganic complex on the electrochemical behavior of the resulting film. We also found that changing the method of metal–phthalocyanine application to the polymer film affected the electrochemical response and kinetics at the electrode surface. The new electrode was tested for the reduction of hydrogen peroxide and showed better conversion efficiency compared to conventional surfaces, which suggests its use in fuel cell applications.     

Immobilization of substituted metall phthalocyanines by nonwoven polypropylene

The specifics of immobilization of water-soluble phthalocyanines on a nonwoven polypropylene (PP), depending on the nature of substitutents and the metal, was studied. The spectral characteristics of the phthalocyanines adsorbed on PP were analyzed.     

Spin dynamics in conducting polymers

It is demonstrated that spin dynamics study is useful for what kinds of systems, on what theoretical basis of analysis, with what kinds of techniques and to get what kinds of information, showing a nice example of polyacetylene. Usefulness of electron spin resonance (ESR) study is stressed especially in a wide frequency range from 5 to 24000 MHz.     

Rigid rod polymers from liquid crystalline phthalocyanines

A number of alkoxy-substituted silicon-dihydroxy-phthalocyanines have been synthesized which form discotic mesophases depending on the side chain length. Metal salt catalyzed polycondensation only gives oligomers while polymer synthesis from activated monomers leads to reasonable high molecular weigths. Indications for the existence of mesophases in this polymer are given.     

纳米结构导电聚合物材料研究进展

具有纳米结构的导电聚合物因其诱人的应用前景越来越引起人们的重视。本文综述了聚苯胺、聚吡咯以及聚噻吩等导电聚合物的零维、一维、二维以及三维纳米结构的合成方法,并介绍了聚合物纳米结构的表征以及研究现状和应用前景。参考文献60篇。     

Prospects of conducting polymers in biosensors

Applications of conducting polymers to biosensors have recently aroused much interest. This is because these molecular electronic materials offer control of different parameters such as polymer layer thickness, electrical properties and bio-reagent loading, etc. Moreover, conducting polymer based biosensors are likely to cater to the pressing requirements such as biocompatibility, possibility of in vivo sensing, continuous monitoring of drugs or metabolites, multi-parametric assays, miniaturization and high information density. This paper deals with the emerging trends in conducting polymer based biosensors during the last about 5 years.     

导电聚合物中的孤子态

指出SSH理论的不足，提出改进与扩充的模型Hamilton量．并对聚乙炔中单双键交替与孤子态的形成机制等作出分析与讨论，提出若干看法，有助于低维电导聚合物理论的完善．     

Spectroscopic studies of conducting polymers

Electronic and vibrational spectra of poly(p-phenylenevinylene) doped with donors or acceptors have been studied, together with the spectra obtained for the radical ions and divalent ions of its oligomers. The electronic absorption spectra of doped poly(p-phenylenevinylene) in the region from visible to near-infrared show two bands for the H₂SO₄-doped species and one very broad band for the Na-doped species. On the basis of the analyses of resonance Raman spectra, the two electronic absorption bands of the H₂SO₄-doped species are attributed to a polaron-lattice structure, whereas the broad band of the Na-doped species is attributed to overlapping absorptions associated with localized electronic levels of polarons and bipolarons. A Pauli spin susceptibility of the H₂SO₄-doped species is explained by the polaron-lattice structure.     

Understanding volumetric capacitance in conducting polymers

Recent measurements in poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) films show that capacitance scales with film volume. We discuss the ramifications of this finding and propose a simple model that describes capacitance in terms of sites in which ions injected from the electrolyte replace holes that are extracted from the film by a metal contact. We propose that volumetric capacitance is inversely proportional to the average distance between these sites. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1433–1436     

Polyphosphonates as ionic conducting polymers

Polyphosphonates, a class of polymers with the generic formula –[P(R)(X)–OR'O]_n–, exhibit a high degree of modularity due to the range of R, R', and X groups that can be incorporated. As such, these polymers may be designed with a polyethylene oxide (PEO) backbone (R' group) and employed as solid polymer electrolytes (SPEs). Two PEO-containing polyphosphonate analogs (R = Ph; X = S or Se) were doped with LiPF₆ and their conductivities were measured. Conductivities were similar (X = S) to or exceeding (X = Se) those of standard PEO systems (just below 10⁻⁴ S/cm at 100°C). Binding models for Li⁺ were generated using ³¹P{¹H}NMR titration experiments. Binding of Li⁺ by these polyphosphonates followed a positive cooperativity model, and varying the X group (S or Se) affected the observed cooperativity (Hill coefficient = 1.73 and 4.16, respectively). The presence of Se also leads to an increase in conductivity as temperature is raised above the T_g, which is likely an effect of reduced Columbic interactions. Because of their modularity and ease with which cation binding can be evaluated using ³¹P{¹H} NMR titration experiments, polyphosphonates offer a unique approach for the modification of Li⁺ ion battery technology.     

Microactuators based on conducting polymers

In this contribution we report the use of polyaniline and polypyrrole for miniaturized actuators fabricated by microstructural and electrochemical technologies. The potential necessary to drive the actuator is typically less than 1 V, i.e. 2-3 orders of magnitude lower than that necessary for the widespread piezoelectric actuator devices. This low voltage is imperative for future application of actuators of micrometer dimensions. The volume variation of polymers substantially exceeds that of piezoelectric materials. Different contributions to the actuator characteristics are discussed and evaluated semi-quantitatively.     

Molecule-to-metal bonds: electrografting polymers on conducting surfaces.

Electrografting is a powerful and versatile technique for modifying and decorating conducting surfaces with organic matter. Mainly based on the electro-induced polymerization of dissolved electro-active monomers on metallic or semiconducting surfaces, it finds applications in various fields including biocompatibility, protection against corrosion, lubrication, soldering, functionalization, adhesion, and template chemistry. Starting from experimental observations, this Review highlights the mechanism of the formation of covalent metal-carbon bonds by electro-induced processes, together with major applications such as derivatization of conducting surfaces with biomolecules that can be used in biosensing, lubrication of low-level electrical contacts, reversible trapping of ionic waste on reactive electrografted surfaces as an alternative to ion-exchange resins, and localized modification of conducting surfaces, a one-step process providing submicrometer grafted areas and which is used in microelectronics.     

Structure and electronic properties of ladder polymers. A new class of conducting polymers

Theoretical calculations have been applied to design novel synthetic polymers which show metallic conductivity without doping. Some selected highly conjugated structures were calculated using a HUCKELMO method extended by introducing elastic sigma bonds. A group of highly conjugated aromatic ladder polymers is promising in this context. Another interesting group consists of laddered heteroaromatic structures in which carbon atoms are replaced by nitrogen. Ionization potentials, electron affinities, band widths, band gaps as well as oxidation and reduction potentials were calculated. Small, band gaps were obtained for polyacene, polyperinaphthalene and polypyridinopyridine. The values are in good aggreement with that obtained on the basis of the VEH method. This paper reports also some efforts to prepare polyacene, polyperinaphthalene and polypyridinopyridine, and to investigate their electronic properties. Concerning their electrochemical properties high specific capacities and good electrochemical stability has been found in aprotic lithium cells.     

Immobilization of invertase in conducting copolymers of 3-methylthienyl methacrylate

Immobilization of invertase in conducting copolymer matrices of 3-methylthienyl methacrylate with pyrrole and thiophene was achieved by constant potential electrolysis using sodium dodecyl sulfate (SDS) as the supporting electrolyte. Polythiophene (PTh) was also used in entrapment process for comparison. Kinetic parameters, Michaelis-Menten constant, K(m), and the maximum reaction rate, V(max), were investigated. Operational stability and temperature optimization of the enzyme electrodes were also examined.