Electro-conducting polymers

The authors thanks Dr. M. Katsitadze - for the synthesis of l,3-dimethyl-l,3-dioctyledisiloxane and 1.4-bis(dihydridcdimctylhyl)bcnzcnc, also Prof. Dr. Aneli and Dr. D. Gventsadze - for study of created electro-conducting polymer composites. 

Three types of blends belong to this group (1) molecular composites, i.e., the molecular LCP solutions, (2) immiscible blends of LCP, and (3) blends of electro-conductive polymers. 

It is well known that the extended coniugation of monommc residues is the fundamental property which determines the extent of electroconductivity of an organic polymer.58 The polymer precursor route used to improve the processability of electro-conductive polymers... 

Polysilanes have been investigated as the raw materials of new ceramics, photoresist polymers for high resolution lithography, semiconductors, electro-conductive polymers, etc. [46]. Polydimethylsilane is prepared by adding di-chlorosilane to the dispersed minute particles of sodium in toluene solution. 

Yoneyama, H., K. Kawai, and S. Kuwabata Light-Localized Deposition of Electro-conductive Polymers on n-Type Silicon by Utilizing Semiconductor Photocatalysis. J. Electrochem. Soc. 135, 1699 (1988). 

Electrochemical polymeriza tion of heterocycles is useful in the preparation of conducting composite materials. One technique employed involves the electro-polymerization of pyrrole into a swollen polymer previously deposited on the electrode surface (148—153). This method allows variation of the physical properties of the material by control of the amount of conducting polymer incorporated into the matrix film. If the matrix polymer is an ionomer such as Nation (154—158) it contributes the dopant ion for the oxidized conducting polymer and acts as an effective medium for ion transport during electrochemical switching of the material. 

In the field of soluble conducting polymers new data have been published on poly(3-alkylthiophenes " l They show that the solubility of undoped polymers increases with increasing chain length of the substituent in the order n-butyl > ethyl methyl. But, on the other hand, it has turned out that in the doped state the electro-chemically synthesized polymers cannot be dissolved in reasonable concentrations In a very recent paper Feldhues et al. have reported that some poly(3-alkoxythio-phenes) electropolymerized under special experimental conditions are completely soluble in dipolar aprotic solvents in both the undoped and doped states. The molecular weights were determined in the undoped state by a combination of gel-permeation chromatography (GPC), mass spectroscopy and UV/VIS spectroscopy. It was established that the usual chain length of soluble poly(3-methoxthythiophene) consists of six monomer units. 

Coutanceau C, El Hourch A, Crouigneau P, Leger JM, Lamy C. 1995. Conducting polymer electrodes modified by metal tetrasulfonated phthalocyanines Preparation and electro-catalytic behaviour towards dioxygen reduction in acid medium. Electrochim Acta 40 2739-2748. 

These results illustrate that electrochemical techniques can be employed to synthesize a vast range of [Si(Pc)0]n-based molecular metals/conductive polymers with wide tunability in optical, magnetic, and electrical properties. Moreover, the structurally well-defined and well-ordered character of the polymer crystal structure offers the opportunity to explore structure/electro-chemical/collective properties and relationships to a depth not possible for most other conductive polymer systems. On a practical note, the present study helps to define those parameters crucial to the fabrication, from cheap, robust phthalocyanines, of efficient energy storage devices. 

Some theoretical prerequisites for application of modified and expanded graphites, Si- and Sn-based composites and alloys, electroconducting polymers as active materials, catalysts and electro-conductive additives for lithium - ion batteries, metal-air batteries and electrochemical capacitors are considered. The models and the main concepts of battery-related use for such materials are proposed. 

Using synthesized diallylsilazanes modification of the properties of some important industrial polymer composites based on phenolformaldehide resins has been carried out. Preliminary investigations showed that synthesized polymers in combination with phenolformaldehyde resins were successfully used as binding-components for polymer/graphite and polymer/carbon black electro-conducting composites. 

Besides the aforementioned, preliminary investigations showed that synthesized oligomers and polymers, in combination with phenolformaldehyde resin, were successfully used as binding component for polymer/graphite electro-conducting composites (ECC) [15, 16], Obtained ECC were recommended for creation of electrode material for electrolytic section and the chemical (fuel) sources of electrical energy (on the basis of analogous material) [16],... 

Zawodzinski, T. A., Davey, J., Valerio, J. and Gottesfeld, S. 1995. The water-con-tent dependence of electro-osmotic drag in proton-conducting polymer electrolytes. Electrochimica Acta 40 297-302. 

Fig. 11.11. Evolution of the visible spectrum during anodic oxidation of 36 mM pyrrole in aqueous 1 M KN03 solution on stainless steel grid electrode at 0.7 V (SCE). Spectra were obtained at 60-s intervals. (Reprinted with permission from D. J. Fermin, M. Mostany, and B. Scharifker, Electronically Conducting Polymers Synthesis and Electrochemical Properties of Polypyrrole, Curr. Topics Electro-chem. 2 132-136,1993.)...

Nobel Prize Chemistry to Alan J. Heeger, Alan G. MacDiarmid and Hideki Shirakawa for their discovery and development of conductive polymers (i.e. electro-luminescent conjugated polymers)... 

In analysis of ionic analytes, SPME can be electro-chemically aided if a conducting fiber, like a -> carbon fiber, is used that is coated with a film of a -> conducting polymer, like -> polypyrrole. Electrostatic uptake and release of the analyte is governed by potential switching that results in oxidation and neutralization of the polymer accompanied by ingress and egress of the analyte ions from the polymer film. 

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