The effect of the initial ratio of components in the formation of a ternary interpolymer complex on its composition and structure

The effect of the initial ratio of components in the formation of ternary interpolymer complexes with low-molecular-mass compounds of various chemical natures on the compositions and structures of polycomplexes has been studied. Complexes based on aniline, 4,4′-dipyridyl, lysine, poly(acrylic acid), and the sodium salt of polyphosphoric acid have been examined. It has been shown that an increase in the content of poly(acrylic acid) in the pristine reaction system results in a relative gain in its content in the reaction product.     

Specifics of structural organization and properties of lysine dendrimers of different generations and related supramolecular structures

Lysine dendrimers of different generations containing covalently attached anthracene-based luminescent labels (one label per six dendrimer molecules) and fifth-generation heterodendrimers containing various amino acid units located between lysine fragments were synthesized. Homodendrimers were studied by means of the polarized luminescence technique. It was found that the packing density of lysine fragments in macromolecules increases with an increase in the generation number. Their capability of forming supramolecular structures changes in this case; the number of polymacromolecular associates produced in the solution and on the polymer matrix in interpolymer complexes decreases and their complexing power in the reaction with low-molecular-mass compounds increases. It was found that dendrite molecules acquire a looser structure on passing to heterodendrimers and their complexing ability varies in the corresponding manner; the number of polymacromolecular associates in the solution and on the polymer matrix in the interpolymer complexes increases and binding of low-molecular-mass compounds is reduced.     

Ternary interpolymer complex based on aniline

On the basis of aniline, poly(acrylic acid), and sodium polyphosphate, a ternary interpolymer complex with a monobasic amine comprising an aromatic ring without any substituents and two polyacids has been prepared. The composition, structure, and behavior of the complex in aqueous solutions containing a low-molecular-mass salt have been investigated.     

Features of the formation of interpolymer complexes of poly(carboxylic acids) and nonionic polymers in aqueous solutions in the presence of low-molecular-mass electrolytes

The published experimental data on the interpolymer reactions that involve nonionic polymers and poly(carboxylic acids) in aqueous solutions in the presence of low-molecular-mass electrolytes have been analyzed. A theoretical approach that allows one to interpret the character and direction of a shift in the critical pH values of the complexation reaction due to the effect of low-molecular-mass electrolyte has been proposed. It has been found that the character of interactions between poly(carboxylic acids) and nonionic polymers in the presence of a low-molecular-mass salt is significantly influenced by the processes of local ion exchange resulting in the heterogeneous distribution of low-molecular-mass ions throughout the solution volume.     

Effect of pH on complexation in mixed dilute aqueous solutions of poly(acrylic acid), poly(ethylene glycol), and Cu2+ ions

The phase states of mixed dilute solutions of PAA, PEG, and Cu²⁺ ions largely determines the mechanism governing the growth of metal nanoparticles during the subsequent reduction of copper ions. Mixtures with PAA: PEG > 1 base-mol/base-mol and PAA: Cu²⁺ ≥ 5 base-mol/mol are studied. It is shown that the simultaneous complexation of PAA with PEG and Cu²⁺ ions in these mixtures at pH values below the intrinsic pH of a solution is accompanied by phase separation related to insolubility of PAA-PEG interpolymer complexes. A decrease in the pH of the ternary mixture is caused by the release of a strong low-molecular-mass acid due to complexation with Cu²⁺ ions. The minimum pH value, above which the PAA-PEG-Cu²⁺ system becomes single-phase (a transparent solution), depends on the concentration ratio between PAA and PEG chains (the mean degree of polymerization). This value is either 6.8–7.0 (if all macromolecules are incorporated in the insoluble interpolymer complex with PEG) or 4.0 (if chains occur in excess). Methods of preparing single-phase systems in the pH range 4.0–7.0 via exchange reactions of the PAA-Cu²⁺ complex with PEG or the nonstoichiometric soluble interpolymer complex PAA-PEG are developed. Viscometry, electron microscopy, and dynamic light scattering are used to investigate the compositions and structures of soluble complexes, in which either each chain (if the chain is long) may be linked with both PEG and Cu²⁺ ions or PAA chains are redistributed between two complexes (at comparable lengths of PAA and PEG chains).     

Complex formation of polyvinyl ether of diethylene glycol with polyacrylic acid II. Effect of molecular weight of polyacrylic acid and solvent nature

In the present work the complexation between polyvinyl ether of diethylene glycol and polyacrylic acid of different molecular weights has been studied in aqueous and isopropanol solutions. It was found that the polyacrylic acid with molecular weight 2000 does not form interpolymer complexes. The stability of polycomplexes in respect to addition of different solvents was evaluated. It was shown that depending on the nature of polymers the interpolymer complexes may be more or less stable in aqueous solutions than in organic ones.     

The formation of interpolymer complexes in mixtures of weak polyelectrolytes

How the specific features of the formation of interpolymer complexes in nonstoichiometric mixtures of weak and strong polyelectrolytes depend on their concentrations, their degrees of polymerization, the polyelectrolyte weakness, and the low-molecular-mass salt concentration were investigated. Theoretical results are in qualitative accordance with experimental data.     

Solvent effects on the formation of nanoparticles and multilayered coatings based on hydrogen-bonded interpolymer complexes of poly(acrylic acid) with homo- and copolymers of N-vinyl pyrrolidone

The formation of hydrogen-bonded interpolymer complexes between poly(acrylic acid) and poly(N-vinyl pyrrolidone) as well as amphiphilic copolymers of N-vinyl pyrrolidone with vinyl propyl ether has been studied in aqueous and organic solutions. It was demonstrated that introduction of vinyl propyl ether units into the macromolecules of the nonionic polymer enhances their ability to form complexes in aqueous solutions due to more significant contribution of hydrophobic effects. The complexation was found to be a multistage process that involves the formation of primary polycomplex particles, which further aggregate to form spherical nanoparticles. Depending on the environmental factors (pH, solvent nature), these nanoparticles may either form stable colloidal solutions or undergo further aggregation, resulting in precipitation of interpolymer complexes. In organic solvents, the intensity of complex formation increases in the following order: methanol < ethanol < isopropanol < dioxane. The multilayered coatings were developed using layer-by-layer deposition of interpolymer complexes on glass surfaces. It was demonstrated that the solvent nature affects the efficiency of coating deposition.     

The effect of a low-molecular-mass salt on stoichiometric polyelectrolyte complexes composed of oppositely charged macromolecules with different solvent affinities

The effect of a low-molecular-mass salt on the thermodynamic stability of stoichiometric interpolymer complexes composed of oppositely charged macromolecules with different solvent affinities has been theoretically studied. It has been shown that the dissociation of such complexes with an increase in the concentration of the salt proceeds via several stages. At a low concentration of the salt, complexes retain their structure and dimensions. When a certain critical concentration of the salt n _s^cr is achieved, the dimensions of the complex increase abruptly. At this concentration, macromolecules involved in the complex begin to separate, and at concentration n _s^*, they fully move apart but remain soluble owing to the polyelectrolyte effect. Upon a further increase in the concentration of the salt, the polyelectrolyte effect is shielded and the dimensions of macromolecules decrease. The critical concentration of the low-molecular-mass salt, n _s^cr, increases with an increase in the degree of ionization of macromolecules and a decrease in the affinity of the hydrophilic component for water and diminishes with the degree of polymerization of macromolecules and the degree of hydrophobicity of a polycation. Because of the easy formation of soluble complexes from oppositely charged macromolecules differing in solvent affinities and their high stability in solutions of a low-molecularmass salt, such complexes are promising for wide use in medicine and pharmaceutical practice.     

Gas-separation membranes based on interpolymer complexes of sulfonate-containing aromatic polyamides

The gas-separation properties of membranes prepared from sulfonate-containing aromatic polyamide and aliphatic polyamines are studied. With the use of potentiometry, IR spectroscopy, and elemental analysis, it is shown that interpolymer complexes arising in these systems are primarily stabilized by electrostatic forces, while the degree of transformation in them is dependent on the basicity of polyamine and the conditions of the interpolymer reaction. The relationship between the nature of polyamine, the composition of the interpolymer complex, and the degree of transformation in it and the gas-separation characteristics of the membranes is established.     

Solvent effect on H-bond cooperativity factors in ternary complexes of methanol, octan-1-ol, 2,2,2-trifluoroethanol with some bases

Cooperative hydrogen bonds in ternary complexes (ROH)(2)...B (ROH-alcohols; B-bases) formed in pure bases (B) and solutions in n-hexane, carbon tetrachloride, benzene and 1,2-dichloroethane were studied by FTIR spectroscopy. Based on the observations, the authors were able to propose an original method of evaluating solvent effects on cooperativity factors in the complexes. Frequencies of cooperative hydrogen bonds OH...B (nu(b)) were determined for ternary complexes of pyridine with aliphatic alcohols (methanol, octan-1-ol) and for 2,2,2-trifluoroethanol with three different bases (acetonitrile, diethyl ether, tetrahydrofuran). The solvent shifts of nu(b) were found to correlate with an empirical thermochemical parameter of the solvent, S(VW). The cooperativity factors were determined for the complexes (ROH)(2)...B in all studied media. It has been found that the cooperativity factors are almost independent of the solvent. In addition, a method was proposed of estimating the frequencies and cooperativity factors for ternary complexes (ROH)(2)...B in the gas phase. It has been found that in gas phase the cooperativity factors are practically the same as in condensed media.     

Interpolymer complexes of copolymers of vinyl ether of diethylene glycol with poly(acrylic acid)

 The complex formation reactions of poly(vinyl ether of diethylene glycol) as well as vinyl ether of diethylene glycol–vinyl butyl ether copolymers with poly(acrylic acid) have been studied in aqueous and alcohol solutions. The formation of interpolymer complexes which were stabilized by hydrogen bonds was shown. The effects of molecular weight of poly(acrylic acid) and the nature of the nonionic polymer on the composition and stability of interpolymer complexes were clarified. The critical pH values of complexation were determined for different systems with various molecular weights and hydrophobic–hydrophilic balances. The stability of the interpolymer complexes formed in aqueous and alcohol solutions with respect to dimethylformamide addition was evaluated. The role of hydrophobic interactions and the presence of active groups on stability of the interpolymer complexes is discussed. Received: 23 July 2001 Accepted: 27 September 2001     

Photochemical behavior of polymer complexes based on Eu(III) acrylato(bisdibenzoylmethanate)

The photochemical behavior of monomer and polymer complexes of Eu³⁺ that are based on dibenzoylmethane and acrylic acid has been studied. It has been shown that these complexes differ from their low-molecular-mass analogs by properties: in the course of photolysis, the intensity of luminescence of the studied Eu³⁺ complexes increases by a factor of 1.3 to 2.5. The mechanism describind the effect of the composition of polymer formulation on the rate of photodegradation is discussed.     

Mixed Ligand Complexes of Ni(II) with Arylidene- Anthranilic Acids and Some Lewis Bases

Some binary and ternary complexes of Ni(II) with arylideneanthranilic acids and Lewis bases have been prepared and characterized by elemental analyses, IR spectra and X-ray powder diffraction. On the basis of the IR spectra it was found that the Schiff bases used act as monobasic bidentate ligands except for the ortho-hydroxy derivative which acts as a dibasic tridentate ligand. From X-ray analysis it is concluded that the binary Ni(II) chelates are isostructural, and the ternary Ni(II) complexes are also isostructural.     

Novel supramolecular assembly of symmetrical mixed-metal-ligand complexes of dioxouranium(VI)

Some binary and ternary novel complexes of dioxouranium(VI) with 8-hydroxy-7-quinolinecarboxaldehyde (OXH) have been prepared and characterized by elemental analyses, magnetic susceptibility measurements and spectral studies. Coordination effects on the vibrational spectra of the ligands have been investigated. The amine exchange reactions of coordinated Schiff bases in these complexes have been also studied, which reveal symmetrical tetradentate Schiff base complexes. Metal exchange reaction of dioxouranium(VI) complexes was obtained when reacted with tetradentate Schiff base complexes of Cu(II) with ZrCl(4)/UO(2)(CH(3)COO)(2) giving heterobinuclear complexes. Magnetic, electronic and IR spectral data suggest the configurations of distorted square planar ligand field copper(II) complexes. The ligands behave as bi-(O,O) and tetradentate (N(2),O(2)) donors. El-Sonbati equation has been used to evaluate the symmetric stretching frequency from which the F(U-O) and F(UO,UO)(-) were calculated. The bond distances of these complexes were also investigated.     

The Structure and Properties of TiO(2)-Cu(II)-EDTA Ternary Surface Complexes

The formation, composition, structure, and electrochemical properties of ternary surface complexes between copper(II) and ethylenediaminetetraacetate adsorbed on TiO(2) xerogels and on thin-film TiO(2) electrodes from solutions of varying pH have been studied by potentiometry, EPR spectroscopy, and electrochemical methods. The results strongly indicate that, in contrast to other organic ligands, B-type ternary surface complexes are formed in this system. The organic ligand forms an isolating layer between the surface of the TiO(2) electrode and the redox-active copper ions. Copyright 2001 Academic Press.     

Photoluminescent Eu3+/Tb3+ hybrids from the copolymerization of organically modified silane

A novel series of organic/inorganic/polymeric hybrid materials have been constructed from covalently bonding rare earth complexes into the inorganic matrix and polymer backbone. Among functional linkage, 3-chloropropyltrimethoxysilane is used to modify the hydroxyl group of p-hydroxycinnamic acid via substitution reaction to form the precursor, and the precursor is subsequently used to covalently bonding to acrylic acid, methyl acrylate, and vinyltriethoxysilane, respectively, through copolymerization reaction to form the organic/inorganic/polymeric network. In addition, we introduce the monomer 1,10-phenanthroline as the second reagent ligand for constructing the ternary luminescent hybrid material systems (abbreviated as HC-PMA-RE, HC?=?p-hydroxycinnamic acid and 3-chloropropyltrimethoxysilane). The physical characterization and especially the photoluminescence property of ternary system are studied in detail, which present the regular microstructure and characteristic photoluminescence.     

New elastomeric networks based on functionalized ethylene–propylene rubbers and hydroxyl terminated polybutadiene. I. A kinetic study on the monoesterification

Ethylene–propylene random copolymers bearing grafted succinic anhydride functions have been reacted with an α,ω-hydroxyl telechelic polybutadiene to obtain elastomeric interpolymer complexes. A kinetic study has been carried out by infrared techniques to study the influence of the addition of catalyst, stoichiometry, and temperature on the degree of monoesterification reaction.     

Ternary surface complexes in silica-Ni2+ ions-2,2′-dipyridyl systems

The adsorption of complexes of nickel ions with an organic base (2,2′-dipyridyl) at an interface between silica and an aqueous electrolyte solution has been considered in terms of the theory of complexation. It has been shown that, on the silica surface, ternary complexes are formed, in which nickel ions are bonded to silanol groups. The equilibrium constants of the reactions of ternary surface complex formation have been calculated from the adsorption curves describing the pH dependences of nickel ion and dipyridyl adsorption.