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In this work, the morphology and stability of coatings formed from polydimethyldiallylammonium chloride, as well as its complex with sodium polystyrenesulfonate, on the surface of glass and polycarbonate were studied. It has been established that the modification of a polycation with a polyanion makes it possible to increase the resistance of the formed coatings to wash-off with water, ensuring the creation of effective antibacterial coatings on various surfaces. [ABSTRACT FROM AUTHOR]

IR spectroscopy is used to show that aerogels based on the interpolyelectrolyte complexes (IPEC) form in slightly acidic aqueous solutions at initial molar ratios ≥1.5 of aqueous solutions of chitosan and sodium alginate. Two to three times more hydroxylophine (in sc-CO2) can be introduced into AG-based matrices than into the corresponding polymer films of the same mass, due obviously to the larger surface area of the AG. It is found the preliminary solubilization of TAI with pluronic F-127 contributes to additional slowing of the release of the active substance from the matrices into a model biological environment. [ABSTRACT FROM AUTHOR]

In this paper we give the overview of our latest results on the complexation between polyelectrolytes and oppositely charged low-molar mass species, proteins, homopolymers and block copolymers. First, we review the results on the study of the interaction of polythiophene-based polycations with phosphonium and ammonium pendants and their complexation with negatively charged multivalent species followed by fluorescence quenching. We proved that multivalent solutes bind to polyelectrolyte stronger than to previously studied polythiophene, thus, allowing for their application as luminescence sensors. Secondly, we investigated the co-assembly of polyanion with double hydrophilic block copolymer composed of polycationic block and neutral hydrophilic block and followed the complex formation by quenching of fluorescence of the indicator attached to the end of polyanion chain. We discovered that the formed interpolyelectrolyte (IPEC) core of core/shell micelles remains dynamical even after equilibrium was reached thus making such systems suitable materials for targeted delivery of multivalent species. In addition, the formation of micelles with fluid cores was observed as a result of self-assembly of di- and triblock polyelectrolytes containing a hydrophobic block with low glass transition temperature and a positively charged block. We proved their ability to encapsulate and release hydrophobic species from the soft core upon dilution. Moreover, we confirmed their ability to complex with multivalent negatively charged species. The morphology of the formed complex strongly depends on ionic strength: the aggregates formed by micelles bonded at the periphery disrupt with increasing salt concentration and a part of multivalent ions releases into solution. Finally, the multilayered nanoparticles with both soft hydrophobic and IPEC layers were designed by co-assembly between core/shell micelles with a soft core and a positively charged shell, and block polyelectrolyte composed of polyanion and neutral hydrophilic blocks. We showed that the morphology of the particles and the charge of IPEC layer of such multicompartment nanostructures can be controlled by the ratio of oppositely charged monomeric units. [ABSTRACT FROM AUTHOR]

This paper investigates the structure, morphology and antimicrobial properties of silver-containing nanocomposites based on interpolyelectrolyte complexes (IPEC) of pectin with polyethylenimine, cationic starch or chitosan as a cationic polyelectrolyte. The reduction of silver ions was carried out by thermochemical technique by heating of the interpolyelectrolyte–metal complexes, which in turn prepared by adsorption of ions on IPEC. The chemical reduction was also performed using ascorbic acid as reductant. The temperature and time needed to produce the nanocomposites at which completely reduction of silver ions occurs are 150 °C and 30 min. It is revealed that during thermochemical reduction depending on the type of cationic polyelectrolyte (PEI, cationic starch, chitosan), silver nanoparticles with an average size of 4.1, 5.3 and 4.7 nm, respectively, are formed. Various mechanisms of thermochemical reduction for interpolyelectrolyte–metal complexes containing polymers with aminogroups or polymers with the glucopyranose units are considered. It is found that the silver-containing nanocomposites, formed by thermochemical reduction, exhibited higher antimicrobial activity against strains of S. aureus and E. coli than ones obtained using ascorbic acid. [ABSTRACT FROM AUTHOR]

The structure and properties of Cu/Cu2O-containing nanocomposites formed by chemical reduction of Cu2+ ions in interpolyelectrolyte–metal complexes (IMC) at different molar ratios [NaBH4]: [Cu2+] and reduction times were studied by methods of wide- and small-angle X-ray scattering, transmission electron microscopy, thermomechanical analysis, and antimicrobial tests. Optimal conditions ([NaBH4]: [Cu2+] = 6.0, reduction time ≥ 120 min) for the formation of copper-containing nanocomposites based on interpolyelectrolyte complexes and Cu/Cu2O core–shell nanoparticles have been established by X-ray diffraction analysis. Owing to the above conditions, the structural manifestation of the metal copper phase is fully realized. Applying transmission electron microscopy, it was found that at molar ratio [NaBH4]: [Cu2+] = 6.0, and reduction time of 40 min and 180 min, accordingly, the nanocomposites with average nanoparticles size of 4.1 nm and 12.4 nm are derived from IMC, respectively, what correlates with effective size of the nanocomposites' heterogeneity regions, lp. Thermomechanical analysis has shown that raise in the amount of reducing agent or the duration of reduction of Cu2+ ions in IMC is accompanied by elevation in the glass transition temperature, which reaches a constant level, boost in the temperature of transition to the viscous state Tf and decrease in the relative deformation of nanocomposites. The antimicrobial investigations of the elaborated nanocomposites revealed they possess an antimicrobial activity against S. aureus and E. coli strains. [ABSTRACT FROM AUTHOR]

The structure and properties of silver-containing nanocomposites formed by the method of thermochemical reduction of Ag+ ions in polyelectrolyte-metal complexes pectin–Ag+–polyethyleneimine were studied using X-ray diffraction analysis, thermogravimetric analysis, pyrolysis mass spectrometry, transmission electron microscopy and antimicrobial test. The optimal parameters for the formation of nanocomposites based on interpolyelectrolyte complexes of pectin–polyethyleneimine and Ag nanoparticles (reduction temperature T = 150 °C, reduction time t = 30 min) have been found by X-ray diffraction analysis, in which the structural manifestation of the silver metal phase is fully realized. Using transmission electron microscopy, it was found that nanocomposite formed by thermochemical reduction of Ag+ ions at 150 °C for 30 min has an average nanoparticle size of 4.1 nm that less than for nanocomposite obtained at T = 120 °C during the same reduction time (average nanoparticle size is 5.8 nm). Ag nanoparticles obtained by using a typical reducing agent (NaBH4) have an average size equals 3.8 nm. It was revealed that nanocomposites obtained by thermochemical method have significantly higher antimicrobial activity compared with nanocomposites obtained by chemical reduction of Ag+ ions using NaBH4. A mechanism of thermochemical reduction of silver ions in IMC pectin–Ag+–polyethyleneimine, which is based on the transfer of electrons from the nitrogen atoms of amino groups PEI to Ag+ ions, has been investigated by destructive processes that occur at the same time. [ABSTRACT FROM AUTHOR]

The specific features of the formation of metal nanoparticles under X-ray radiation in interpolyelectrolyte complex (IPEC) films based on polyacrylic acid and polyethyleneimine with different silver ion content were studied. IPEC films were irradiated in aqueous-alcoholic medium. Electron microscopy demonstrated that the formation of silver nanoparticles occurred in zones regularly located by film thickness. It was found that nanoparticle size and spatial distribution in IPEC films depended on the initial concentration of silver ions within the sample and on the absorbed dose of radiation. The obtained film nanocomposites are promising objects for application as antibacterial and catalytic materials. [ABSTRACT FROM AUTHOR]

Film membranes were prepared from interpolyelectrolyte complexes of various aliphatic polyamines with a copolyamide synthesized from isophthalic dichloride and two diamines: disodium 4,4′-diaminobiphenyl-2,2′-disulfonate and 4,4′-diaminodiphenylmethane-2,2′-dicarboxylic acid. The mechanical and sorption properties of the membranes and their performance in pervaporation separation of the water-isopropanol mixture were studied. The possibility of thermal cross-linking of the materials was demonstrated. The effect of the amidation on the physicochemical and mass-exchange properties of the film samples was examined. The variation of the separation characteristics of the membranes depending on the copolyamide composition was considered. With respect to the combination of separation and transport properties, the interpolymer systems containing the copolyimide with low (7 mol %) content of units with carboxy groups are of most interest. An increase in the fraction of carboxyl-containing units in the polyanion leads to an increase in the permeability of the materials with a significant decrease in their selectivity. The tensile strength of the film samples prepared from copolyamide-containing interpolyelectrolyte complexes is 54–92 MPa. [ABSTRACT FROM AUTHOR]

Conditions for the preparation of stable to sedimentation aqueous dispersions of interpolyelectrolyte complexes based on chitosan (Chit) and pectin (Pect) with particle diameter 0.5-0.9 μm for Pect/Chit and 1.0-2.0 μm for Chit/Pect have been determined. The absolute value of the zeta potential of these complexes is >10 mV for Pect/Chit and Chit/Pect when the molar ratio of the ionogenic groups of the polymers nCOOH/nNH2 is 0.4-4.6 for Pect/Chit and 0.02-0.63 for Chit/Pect. Optical spectroscopy and electrophoretic light scattering have been used to determine the effect of molecular mass and the content of the free ionogenic groups in the polysaccharide macromolecules as well as the order of mixing the solution on the formation and properties of these interpolyelectrolyte complexes. [ABSTRACT FROM AUTHOR]

The structural organization and thermomechanical properties of nanocomposites prepared from interpolyelectrolyte-metal complex (IMC) involving anionic polyelectrolyte, pectin and AgNO, and cationic polyelectrolyte, poly(4-vinylpyridine), have been investigated using the methods of wide- and small-angle X-ray scattering and thermomechanical analysis. It is established that chemical reduction of Ag ions in the IMC by sodium borohydride results in formation of the nanocomposite based on the 'pectin-poly(4-vinylpyridine)' interpolyelectrolyte complex (IPEC) and Ag nanoparticles as well. At the same time, the level of nanocomposites' structural heterogeneity is substantially enhancing, while effective size of the heterogeneity regions decreases. The nanocomposites IPEC-Ag prepared are shown much bigger T value and enhanced ability for deformation than those for IMC. [ABSTRACT FROM AUTHOR]

Applying wide-angle X-ray scattering method, thermomechanical analysis, and differential scanning calorimetry, the structural organization and properties of nanocomposites formed by chemical reduction of Сu cations in the interpolyelectrolyte-metal complex (pectin-Cu-polyethyleneimine) under the influence of a constant magnetic and electric fields have been studied. It has been found that the chemical reduction of Cu cations in the interpolyelectrolyte-metal complex bulk under constant electric and magnetic fields leads to formation of nanocomposite consisting of interpolyelectrolyte complex, including pectin-polyethyleneimine and nanoparticles of the metal Cu phase, whereas nanocomposite with Cu/CuO nanoparticles is formed in original state (without any field). It was observed that, under constant field, nanocomposites obtained have higher structural glass-transition temperatures and thermal stability. [ABSTRACT FROM AUTHOR]

This review considers interpolyelectrolyte complexes, with a particular emphasis on advanced macromolecular co-assemblies based on polyionic species with nonlinear topology and on polymer–inorganic hybrids formed by interpolyelectrolyte complexes containing metal ions and/or metal nanoparticles. [ABSTRACT FROM AUTHOR]

New interpolyelectrolyte complexes (IPECs) between oppositely charged types of Eudragit EPO and Eudragit L100 - 55 were investigated with a view to their application in oral controlled drug delivery systems. Monitoring of microenvironmental changes of polycomplex matrices in simulated gastro-intestinal fluids showed that all IPECs could have different pH-sensitivity characteristics. Evaluation of the diffusion transport properties of the investigated IPECs with diclofenac sodium confirmed that their swellability and release characteristics were closely correlated. The main possible mechanisms of control over the delivery of drugs to the desired regions of the gastro-intestinal tract are found. The results confirm that the proposed IPEC matrices have great potential to be used for controlled drug delivery. [ABSTRACT FROM AUTHOR]

New interpolyelectrolyte complexes (IPEC) between oppositely charged types of Eudragit, EPO and L100-55, with different molar ratios were synthesized with the aim of seeking potential carriers for oral delivery systems. Elemental analysis showed that the resulting polycomplexes had different compositions, with 0.36 < Z = [EPO]/[L100] < 1.81. The structural properties of the materials assessed by IR spectroscopy and modulated-temperature differential scanning calorimetry showed that all IPEC were stabilized by a cooperative system of ionic bonds, were chemically homogeneous, and were characterized by the presence of a single glass transition temperature. These properties suggest that the polycomplexes synthesized here have potential for further study as carriers for controlled drug release in specified parts of the gastrointestinal tract. [ABSTRACT FROM AUTHOR]

The formation of interpolyelectrolyte complexes (IPEC) between Eudragit EPO (EPO) and Carbomer 940 (C940) was investigated with a view to their use in peroral controlled-release drug delivery systems. The structure of the synthesized products was investigated using FTIR spectroscopy and MT-DSC methods, which indicated that the synthesized product can be considered to be an IPEC stabilized by a cooperative system of ionic bonds. Based on results of capillary viscosimetry and elemental analysis, the IPEC prepared at pH 4.0 has a characteristic composition with a C940:EPO mole ratio of 1.75:1. [ABSTRACT FROM AUTHOR]