Electrical conductivity of paper

This paper describes some recently completed work on the electrical conductivity of paper. A reliable method of measuring bulk conductivity of paper, where the contact resistance is reduced to negligible values, has been developed. A study of the effect of some papermaking variables, such as the type of pulp, the degree of refining and the fiber orientation, on the bulk conductivity of paper is reported. Finally, an investigation has been made into the current transient phenomena exhibited by paper upon the application of an electric field. These transient currents were interpreted as the transport of ionic species within a water associated fibrous network making up the paper. 

JOSF.FOWICZ AND deslandes Electrical Conductivity of Paper 497... 

Reproducible and accurate measurements of electrical conductivity of paper are of great importance in a number of technologies. Two commonly measured electrical parameters of paper are its surface and bulk conductivity. A method for measuring surface conductivity has been reported by Greismer 13, and his recommendations were incorporated in D.C. surface conductivity measurements reported by Howlett and Landheer 14. ... 

Table 7.15 Magnetic susceptibility and electrical conductivity of paper samples...

In paper [141] it was shown that the change in electric conductivity in case of chemisorption of various alkyl radicals on the same oxide is notably dependent on chemical nature of free radicals. In this case the arrangement of simplest radicals in the order of decreasing degree of effect of electric conductivity of ZnO given in [132, 186] will be the following ... 

In order to interpret correctly the results of electrophysical measurements conducted on vacuum - sintered ZnO semiconductor films one should answer the question concerning the origin of contacts between specific crystallites controlling the electric conductivity of the material. This was accomplished in paper [37] using the method of prerelaxation VAC to run a comparative analysis of mechanisms of charge transfer in thin sintered (in vacuum) films and pressed polycrystalline ZnO samples. 

The efficient electric conductivity of such specially-inhomogeneous medium can be calculated in various limiting cases differing by tiie ratio between the local electric conductivity and its average value using methods developed in papers [70-72]. Namely, if the local electric conductivity o(r) slightly differs from the average one [Pg.127]

As it was mentioned in paper [48], expressions (2.44) and (2.45) perfectly describe experimental situation with kinetics of tiie change of electric conductivity of sintered and partially reduced ZnO film during adsorption and desorption of molecular oxygen. Expression (2.44) describes the kinetics of the change of a during adsorption of O2 on ZnO with the surface rich in donors due to photolytic decomposition of ZnO in vacuum fairly well [74]. 

The fair agreement of expressions (2.67) and (2.71) with experimental data as well as agreement of independently obtained experimental data concerning kinetics of the change of a with the data on equilibrium enabled the author of paper [89] to conclude that the proposed mechanism of effect of hydrogen on electric conductivity of semiconductors can be one of active mechanisms. The heat of total reaction (2.63) calculated from the values found was about 4.6 kcal. 

However, the comparison of the whole series of experimental facts involving IR-spectroscopy of adsorption of molecular and atomic hydrogen as well as the change in electric conductivity of adsorbent is indicative of a more complex phenomenon. For instance, in paper [97] both the spectra of adsorption of adsorbed molecular hydrogen were studied together with those of hydrogen atoms adsorbed from gaseous phase. In case when H2 are adsorbed in a dissociative manner one would have expected a manifestation of the same bands 3498 and 1708 cm or at least one of them inherent to adsorption of H-atoms in the spectrum of ZnO. 

In the present work, a somewhat different approach was chosen in order to produce conducting polymers the basic idea was to start with a cheap material, like PVC, and try to remove all the hydrogen and chlorine atoms from the polymer chain. The purely carbon material thus obtained was expected to exhibit the electrical conductivity of a semimetal, while being insensitive to the atmospheric oxygen. In this paper, we report for the first time how PVC can be completely dehydrochlorinated by simple exposure to a powerful laser beam that combines both the photochemical and the thermal effects. 

The increasing importance of multilevel interconnection systems and surface passivation in integrated circuit fabrication has stimulated interest in polyimide films for application in silicon device processing both as multilevel insulators and overcoat layers. The ability of polyimide films to planarize stepped device geometries, as well as their thermal and chemical inertness have been previously reported, as have various physical and electrical parameters related to circuit stability and reliability in use (1, 3). This paper focuses on three aspects of the electrical conductivity of polyimide (PI) films prepared from Hitachi and DuPont resins, indicating implications of each conductivity component for device reliability. The three forms of polyimide conductivity considered here are bulk electronic ionic, associated with intentional sodium contamination and surface or interface conductance. 

Extract the electrodes and drop a small piece of pure metallic sodium thoroughly dried with filter paper into the liquid ammonia. What happens What explains the colouring of the liquid Again introduce the electrodes into the liquid ammonia. How did the electrical conductance of the solution change ... 

The conference was opened with a speech by Lorentz on the theory of electrons he had developed about 20 years before, followed by papers by Joffe on the electrical conductivity of crystals, Kamerlingh Onnes on superconductivity, and Hall on the metallic conduction and the transversal effects of the magnetic field. This last speech was followed by a discussion in which Langevin and Bridgman injected a few interesting remarks. 

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