Metallic doped polymers

Metallic Doped Polymers and Unidentified Organic Superconductors. 101... 

Figure 1.41. Projected equatorial structure (perpendicular to the c-axis) for (a) nominal p4mm symmetry of stage-1 alkali-metal-doped polymers (b) stage-1 alkali-metal-doped polyacetylene (c) stage-1 Cs-doped PPV (Reproduced from ref 104 with kind permission. Copyright (1992) American Physical Society.)...

Formerly, Bradley and Hammes [152] studied dc conductivity phenomma on a number of metal-free and some metal-containing plasma polymers. They foimd plots of Igdc resistivity versus 1/T to be generally linear and concluded that a single activation process is responsible, with activation energies of 1.36 eV for metal-free polymers and < 1 eV for metal-doped polymers. For evaporated Cu/poly-ethylene films [129] the Ig sheet resistance revealed a linear dependence on The conduction process was explained in terms of hopping of electrons between traps in localized states dose to the Fermi level. 

Several workers published memory switching effects in metalfree [85, 156-159] and metal-doped polymer or carbon films [117,158] made in the form of a sandwich metal-polymer-metal. Recently, it has been found that these effects are not likely related to the intrinsic properties of the organic (dielectric) film [157]. More details on composite metal/polymer films can be found elsewhere [159]. 

There have been numerous studies of the electrical and emission properties of conjugated polymer-, small molecule-, and molecularly doped polymer-based OLEDs. The current-voltage and radiance-voltage characteristics have been nica sured as a function of thickness of the organic layer, temperature, different metal electrodes, etc. in an attempt to understand the device physics. A major factor in hibiting progress is the purity of the organic impurities that are incorporated dur-... 

Hur et al. (252,277,278) reported the use of alkali metal-doped MgO to catalyze the synthesis of acrylonitrile and propionitrile (278). Acrylonitrile is an important chemical, especially in the polymer industry it is generally synthesized by the ammoxidation of propene catalyzed by multicomponent bismuth molybdates (279). An alternative method of synthesis of acrylonitrile is the reaction between methanol and acetonitrile (Scheme 42). 

Tetracoordinated copper(H) enhances electron hopping but of the cobalt(II) doped polymers it appears that only those cationic sites adjacent to the metal surface are active. 

Recent band structure calculations have confirmed that the increase in electrical conductivity of doped polymer phthalocyanines is the result of both the existence of partially filled bands and the decrease of the M—M distance.104 They also confirm that the conduction process for the doped polymers changes from metal-centred (M = Cr, Mn, Fe and Co), to ligand and metal (M = Ni) and to ligand-centred (Cu and Zn) with increasing electronegativity of the metal atom along the first transition series. 

FT-Raman will not completely eliminate fluorescence background. Materials that absorb strongly in near-NIR region will present problems (e.g., transition metal complexes, transition metal complex doped polymers, charge-transfer conductors, polycyclic aromatic compounds). Other methods of combatting fluorescence will be discussed in Section 2.7. 

Friedrich JF, Retzko I, Kuhn G, Unger W, Lippitz A (2001) Metal doped plasma polymer films. In Mittal KL (ed) Metallized Plastics, vol 7. VSP, Utrecht p 117-142... 

For PPY-PF6 and PAN-CSA the microwave dielectric constant remains negative in the far IR even at 10-3 K, which shows that there are free carriers even at these low temperatures. These values of the dielectric constants give small values of plasma frequency which shows that only a small fraction of conduction electrons participate in plasma response. Scattering times come out to be 2 orders of magnitude larger than the values for alkali and noble metals. It is predicted that if technology improves, the conductivity of the doped polymers may become larger than that of metals. 

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