Charge Of Poly Research Articles

Optical spectroscopy of field-induced charge in poly(2.5-dimethoxy- p-phenylene vinylene) metal-insulator-semiconductor structures

We have investigated metal-insulator-semiconductor structures fabricated with poly(2,5-dimethoxy- p-phenylene vinylene) as the active semiconductor. In accumulation, we have observed three charge-related absorption features at 0.7eV, 1.7eV and 2.0eV which scale in intensity with the field-induced charge present in the device accumulation layer. We note that the two lower transitions are due to the same state, which can be associated with the presence of long-lived bipolarons, observed in photo-induced absorption. We estimate a value for the optical cross-section associated with the bipolaron absorption at 0.7eV, of around 2 × 10 −15cm 2.

A comparison of the triboelectric charging of poly(tetrafluoroethylene) and an amine-cured fluoroepoxy resin

Abstract Poly(tetrafluoroethylene) and an amine-cured fluoroepoxy resin are compared with respect to the triboelectric charge generated when the surfaces are rubbed against four types of contacting surfaces. In all cases, the fluoroepoxy resin acquires a larger negative voltage than does the poly(tetrafluoroethylene).

Radiation-induced space charge in polymer film capacitors

A space-charge mapping technique was used to observe the formation of x-ray-induced space charge in poly(ethylene terephthalate) and polystyrene capacitor structures. Electronic transport processes, responsible for radiation-induced conductivity in these insulators, produced trapped space charge adjacent to the electrodes. These results were consistent with the conclusions of earlier photoconductivity measurements and revealed injection processes that limit the buildup of space charge.

Poly(dipeptamidinium)‐Salze: Definition und Methoden zur präparativen Herstellung

Poly(dipeptamidinium) Salts: Definition and Methods of PreparationPoly(dipeptamidines) are polypeptide derivatives in which the carbonyl oxygen of each second backbone amide group is replaced by an imine nitrogen (see A). So far, such derivatives have been unknown. Polyprotonated salts of them ( = poly(dipeptamidinium) salts) are of interest in view of their intrinsic constitutional relationship to the structure of polynucleotides: the number of covalent bonds between neighboring centers of positive charge in poly(dipeptamidinium) salts is identical to the number of covalent bonds between neighboring centers of negative charge in natural polynucleotides (see D). Poly(dipeptamidinium) polycations and polynucleotide polyanions are constitutionally and electrostatically complementary structures. Since poly(dipeptamidines) are (formally) polymers of dipeptide nitriles, and, since they can be expected to give polypeptides on hydrolysis, the relationship mentioned above deserves attention and experimental study in context with the problem of designing chemical models of biogenesis.This paper describes methods for the chemical preparation, the spectral characterization, and some chemical properties of homodipeptidic poly(dipeptamidinium) salts in the L‐alanyl‐glycyl and L‐phenylalanyl‐glycyl series. The methods of preparation include a stepwise construction of defined lower oligomers (up to hexamer) as well as, in the L‐alanyl‐glycyl series, a one‐operation poly‐condensation procedure leading to polymers containing an average of ca. 20 dipeptamidinium units (Schemes 4,6 and 7).