M. Ya. Goikhman

New polyamides with main-chain cyanine chromophores

Polyamides containing main-chain cyanine chromophores are synthesized, and their molecular, nonlinear optical, and mechanical properties are studied. It is shown that the Kerr electro-optical effect in polymer solutions is determined by the rigidity of polymer chains and that the nonlinear optical properties are dependent only on the chromophore content.

Luminescence of Ln3+ lanthanide complexes in polymer matrices

The photoluminescence properties of Tb3+ and Eu3+ complexes with polymer ligands containing various kinds of complexing groups—namely, carboxyl (5–20 mol %), pyridylquinoline (5 mol %), or pyridylnaphthyl (5 and 10 mol %) groups—in solution and block are considered. The chemical structure of a neutral comonomer (methyl methacrylate; styrene; isopropyl-, phenyl-, or benzylmethacrylamide; and N-vinylamides) in polymer ligands is varied. The intensity of photoluminescence is dependent not only on the chemical nature of a complexing group but also the chemical nature of a neutral comonomer and a spacer. Variation in the nature of a comonomer and a ligand makes it possible to prepare complexes in which a high luminescence of a low-molecular-mass complex is preserved and advantages inherent in a polymer complex are acquired. The effect of the nature of the polymer matrix (photoactive and photoinert) on the efficiency of electronic-excitation energy transfer is ascertained. The data on the photoluminescence of metal-polymer complexes that are based on polymer ligands containing vinylcarbozole units and that possess hole conductivity make it possible to regard them as materials for electroluminescence. The intensity of photoluminescence of these complexes is related to the competition of oppositely directed photophysical processes in a macromolecule: formation of excimers and migration of electronic excitation energy. An analysis of the published data and of the results of the authors shows that detailed studies of these polymer systems in solution and in matrices are needed to gain insight into the relationship between photo- and electroluminescence properties of metal-polymer complexes, because the matrix plays different roles in photoluminescence and electroluminescence (inner filter or conduction); as a consequence, the emission spectra may differ appreciably. It is shown that the efficiency of electroluminescence may be improved if the transfer of energy from the lanthanide ligand in a complex to the conducting matrix is decreased.

Sorption of vapors of aromatic compounds by cross-linked polymer particles containing luminophores: A spectroscopic study

Monodispersed core-shell particles 290–315 nm in diameter were prepared by seed emulsion copolymerization of styrene with divinylbenzene in the presence of luminophore-containing comonomers. The capability of the particles obtained to sorb toluene vapor was shown by solid-state 1H and 13C NMR spectroscopy.

Crosslinked monodisperse particles containing luminophore groups in shells for molecular recognition of lower alcohols

The molecular imprinting technique is used for the synthesis of monodisperse polymer particles via the seed emulsion copolymerization of methyl methacrylate, ethylene glycol dimethacrylate, and comonomers based on Nile Red. The introduction of lower alcohol templates into the reaction mixture and their removal after the synthesis lead to the formation of molecular-recognition sites in the shell that contain luminophore groups and give an optical response to the presence of methanol and ethanol in the gas phase. The particles are investigated via electron microscopy and dynamic light scattering, and their specific surface area is determined through the BET method. The kinetics of a change in the luminescence of thin films based on the particles in vapors of lower alcohols is investigated.

New macromolecular ligands carrying side pyridylquinoline groups and their metal-polymer complexes with iridium

Copolymers of N-vinylcarbazole and methyl methacrylate carrying side pyridylquinoline groups are synthesized on the basis of the methacrylol derivative of 2-pyridylquinoline-4-carboxylic acid hydrazide. It is shown that the copolymers form stable metal-polymer complexes with Ir(ppy)2Cl (ppy = 2-phenylpyridine). The spectral and photoluminescent properties of the metal-polymer complexes are studied.

Luminescence of terbium and europium ions in metal-polymer complexes based on poly(amido acids) with main-chain arylcarboxyamide groups

Poly(amido acids) with main-chain metal-binding ligands methylene-bis(anthranilic acid) and their linking fragments of a widely varied structure have been synthesized. The chemical structure of poly(amido acids) that affect the luminescence of Tb3+ and Eu3+ ions and interact with them is studied, and the mechanism of this effect is advanced.

Optical and electrical properties of polyamide acid and metal-polymer complex based on terbium

The basic optical and electrical properties of polyamide acid and its complex with Tb+2 have been studied. The occurrence of room-temperature photoluminescence (PL) with an emission peak at 520 nm is established. The activation energy of conductivity at temperatures above 350 K is 2.1 eV. Polyamide acid is comparable in PL intensity with an electroluminescent polymer, poly(p-phenylvinylene).

Mechanical characteristics of films based on comb-shaped poly(amidoimides) with different contents of side chromophoric groups

For films based on poly(amidoimide) with a comb-shaped structure and long side chains, the specific features of the mechanical and thermomechanical behavior and their dependence on the concentration of the above chains are studied. With variation of the composition of the material, changes in the mechanical characteristics show a nonmonotonic character. Comparison of the results of mechanical tests and densimetric measurements allows certain conclusions to be drawn about the character of variations in the structural organization of films with an increase in the concentration of side fragments in macrochains. The role of plasticization in the behavior of the above materials during heating is demonstrated. The advantages of the practical use of the above phenomena for the optimization of the regimes of thermally stimulated polarization of films are discussed.

Thermal aging of carbon- and glass-reinforced plastics based on heat-resistant polyimide binders

A series of fibrous composites, carbon- and glass-reinforced plastics based on heat-resistant polyimide binders, were prepared. The viscoelastic and strength properties of the composites obtained confirm the enhanced heat resistance of the binders.

Electrochemical synthesis of cu-containing polyheteroarylenes and study of their catalytic properties

Method of electrochemical synthesis of new Cu-containing polyheteroarylenes that have biquinolyl units in their main chain is developed on the base of the soluble anode technique. The study of electrochemical properties of thus obtained Cu-containing polymer and the corresponding monomer complex revealed existence of two types of coordination environment: (1) copper Cu(I) in the tetrahedral surrounding of two biquinolyl ligands and (2) copper Cu(I) bound with only one biquinolyl fragment. The complexes with one biquinolyl polymer ligand showed high activity as catalysts for O2 reduction in the presence of hydroquinone that is converted to quinone in the course of the reaction.