Self-Organization and Analysis of the Morphology of Vacuum Evaporated Polyaniline Films

By using formal estimation methods, it is shown that heterogeneous redox structures, which are formed in the course of oxidation of vacuum evaporated thin polyaniline layers in the temperature range of 0–30°C, become more ordered with the increase in the oxidation temperature.     

The influence of polyacid nature on poly(3,4-ethylenedioxythiophene) electrosynthesis and its spectroelectrochemical properties

The present study is aimed to elucidate main structural features of polymeric sulfonic acids (the rigidity of main chain, the distance between sulfonic groups on the chain, the hydrophobicity of main chain or side fragments) on the course of 3,4-ethylenedioxythiophene (EDOT) electropolymerization and electronic and chemical structure of the poly(3,4-ethylenedioxythiophene) (PEDOT) films obtained. The films were prepared by electrochemical polymerization in cyclic voltammetry, potentiostatic, and galvanostatic regimes in aqueous solutions of different polyacids in the absence of supporting electrolyte. The effect of the chemical structure of polyacid on the course and rate of PEDOT synthesis was traced by electrochemical and in situ UV-Vis spectroscopic methods. It was shown that the highest rate of EDOT electropolymerization is achieved in the presence of flexible-chain polyacid having hydrophobic fragments (groups) in its structure, followed by hydrophobic rigid-chain polyacids. The lowest rate was observed in the presence of hydrophilic flexible-chain polyacid. The electronic and chemical structure of the PEDOT films obtained was studied by in situ UV-Vis-NIR and Raman spectroelectrochemistry. The films prepared in the presence of rigid-chain polyacids at high anodic potentials demonstrate decreased content of bipolaronic fragments in their structure, while PEDOT complexes with flexible-chain polyacids are very much like conventional polymer prepared in non-aqueous medium. The results are discussed in terms of conformational state (ability to form coils and thus concentrate the monomer) of different polyacids in aqueous solution and hydrophobic interactions between the polyacids and EDOT.     

Statistical test of a single semiempirical work function model

A semiempirical (regression) model of the dependence of the work function on the crystal-lattice parameter proposed by Surma is considered. Statistical analysis of data on the work function, whose values are obtained by the method of field electron emission, is carried out using tungsten, molybdenum, platinum, and iridium as examples. The homogeneity of the data is shown using parametric and nonparametric criteria. An algorithm for censoring the data is proposed and used; it allows the construction of confidence intervals for the parameters of the studied model within the framework of the normal distribution of its “residuals”. It is established that the regression model turns out to be statistically significant in all considered cases.     

Preparation of polyaniline in the presence of polymeric sulfonic acids mixtures: the role of intermolecular interactions between polyacids

Polyaniline (PANI) was synthesized by chemical oxidation of aniline in the presence of mixtures of water-soluble poly(sulfonic acids) of different nature. Under these conditions, the use of polyacid templates leads to the formation of interpolymer complexes of PANI and polyacid mixtures. The obtained PANI complexes were characterized by UV, visible, near IR, and Fourier transform infrared spectroscopy. It was shown that the rigidity of the polyacid backbone and the composition of a polyacid mixture affect the electronic structure of PANI complexes and the duration of the induction period of aniline oxidation. Domination of the more rigid-backbone template in the synthesis of PANI complexes with mixtures of the rigid- and flexible-backbone polyacids was observed. According to the viscometry and FTIR spectroscopic data, the reason of the domination is the existence of the intermolecular interaction between the polyacids in the mixture. In this case, duration of the induction period of aniline oxidation was between these values for pure polyacids.     

On the Edgeworth expansion and the <Emphasis Type="Italic">M</Emphasis> out of <Emphasis Type="Italic">N</Emphasis> bootstrap accuracy for a Studentized trimmed mean

We investigate the second order accuracy of the M out of N bootstrap for a Studentized trimmed mean using the Edgeworth expansion derived in a previous paper. Some simulations, which support our theoretical results, are also given. The effect of extrapolation in conjunction with the M out of N bootstrap for Studentized trimmed means is briefly discussed. As an auxiliary result we obtain a Bahadur’s type representation for an M out of N bootstrap quantile. Our results supplement previous work on (Studentized) trimmed means by Hall and Padmanabhan [13], Bickel and Sakov [7], and Gribkova and Helmers [11].      

Bootstrap Approximation of Distributions of the L-Statistics

We study consistency conditions of the bootstrap approximation for linear combinations of order statistics with coefficients determined by a weight function. Bibliography: 10 titles.     

Mechanical properties of plasticized chlorinated-polymer film formers

It is shown with reference to three chlorinated polymers (CPVC, VKhVD-40, and PCN) that in the case of structural plasticization the optimum of the physico-mechanical properties corresponds to small amounts (0.02–0.04%) of structural plasticizer in the system. This is associated with the development of relaxation processes at the supermolecular level.State Scientific-Research and Planning Institute of the Paint Industry, Moscow. Translated from Mekhanika Polimerov, Vol. 4, No. 5, pp. 945–948, September–October, 1968.     

Thermal conversions of polymers with macroheterocycles in the chain

Thermal conversion of polyhexazocyclanes and compound modeling the fragments of polymers were explored within 300–600°C under vacuum (10^?5 torr) and in water vapor. At temperatures below 450°C, the hydrolytic degradation plays a key role in the thermal degradation of polyhexazocyclanes. At a higher temperature, the homolytic processes prevail, water, strongly retained by the macroheterocycle, is most important in the hydrolysis process. It was shown that the increase in the thermohydrolytic stability of polymers with the system of condensed cycles in the macroheterocycles and that of polyhexazocyclanes modified by polymer analogous conversion at the secondary amino groups of the isoindole cycle was caused by the absence of bound water.