Evolution of Statistical Ensembles of Microdomains on the Surface of Films of Rigid-Chain Polyimide during Thermal Imidization

Statistical ensembles of microdomains formed on the surface of polyimide films based on pyromellitic dianhydride and 2,7-diaminofluorene during thermal imidization were described in terms of the model of reversible aggregation using the electron-microscopic data. Parameters of the statistical distribution were determined for each ensemble depending on the film heating temperature.     

Thermochemical aspects of interaction of polyimide composites with organic sorbents

Interaction of ITA-31 polyimide binder with a series of industrial sorbents based on styrene and vinylpyridine derivatives was studied.     

Electrochemical and quantum chemical investigation of the CuI and CuII complexes with biquinolyl monomer and polymer ligands

Structural reorganization of polyamide (PA) and low-molecular-weight Cu^I and Cu^II complexes with biquinolyl (biQ) ligands during their mutual redox transformations in solution was studied using the electrochemical methods (cyclic voltammetry and preparative electrolysis) and quantum chemical DFT calculations. The influence of electronic factors and geometry distortions in the complexes on the ionization energy on going from Cu^I to Cu^II was evaluated in comparison. The catalytically active form of the [Cu^I(PA)L₂]BF₄ complex can be synthesized in situ from the stable tetrahedral complex [Cu^I(PA)₂]BF₄ by the series of successive redox transitions Cu^I → Cu^II → Cu^I accompanied by the loss of one biQ-containing macroligand. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1331–1340, July, 2007.     

Dielectric properties of the nanoporous MCM-41 matrix filled with the (NH4)2SO4 ferroelectric

Variations with temperature of the linear dielectric permittivity and amplitude of the third harmonic were studied for nanoporous MCM-41 matrices with 4.0-nm channel pores filled with the (NH₄)₂SO₄ ferroelectric, in comparison with bulk ammonium sulfate. The measurements were performed upon heating and cooling in the temperature range from 100 K to room temperature. A noticeable shift to low temperatures (by approximately 25 K) for the ferroelectric phase transition in the MCM-41/(NH₄)₂SO₄ nanocomposite as compared to bulk (NH₄)₂SO₄ was revealed. The temperature hysteresis observed at the phase transition in the nanocomposite was approximately 2 K which is close to that in bulk ammonium sulfate. The significant decrease of the transition temperature in nanostructured ammonium sulfate agrees with the theoretical predictions based on the Landau and Ising models of the size effect on the ferroelectric phase transition in isolated small particles.     

Influence of Allotropic Forms of Carbon on Formation and Cross-Linking of Heat-Resistant Polymer Binders

The thermochemical reactions of polyimide binder with various allotropic forms of carbon, fullerene C₆₀ and ultradispersed artificial diamonds, were studied by thermal and spectral analyses.     

Study of laws governing the elastoplastic deformation of transversely isotropic bodies

Institute of Mechanics, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Prikladnaya Mekhanika, Vol. 26, No. 9, pp. 50–54, September, 1990.     

The differentiability of volume in Blaschke lattices

Siberian Mathematical Journal -     

Exchange bias in the IrMn/Co structures with alternative sequences of antiferromagnetic and ferromagnetic layers

JETP Letters - The magnetic properties of Mo/IrMn/Co/Mo/SiO2/Si structures with alternative sequences of the antiferromagnetic and ferromagnetic layers have been studied by measuring the angular...     

Iridium metal–polymer complexes based on bipyridyl ligands

Novel polymer macroligands—copolyamides containing different quantity of bipyridyl groups—were obtained from 4,4′-diamino-2,2′-bipyridine, 4,4′-diaminodiphenyl ether and terephthaloyl-bis(3-methoxy-4-hydroxybenzoic) acid dichloroanhydride by low-temperature polycondensation. Metal–polymer complexes with different content of Ir(ppy)2 were obtained by the interaction between polymer ligand and [Ir(ppy)2Cl]₂ (ppy–2-phenylpyridine). The properties of films and coatings based on these materials were studied.