Hydrophilic polymer/inorganic hybrids (PIH) containing silica nanoparticles and polyacrylamide chains proved to be effective matrices for the in situ synthesis of cobalt nanoparticles. PIH sample was synthesized by free-radical polymerization of acrylamide from the unmodified surface of SiO2 nanoparticles and characterized by elemental analysis, dynamic thermogravimetric analysis, static light scattering, potentiometric titration, viscometry and transmission electron microscopy (TEM). The processes of borohydride reduction of cobalt ions from the Co(NO3)2·6H2O solution to nanoparticles in water medium and aqueous solutions of PIH were studied as a function of the concentrations of metal salt and hybrid concentrations using UV-Vis spectroscopy and TEM. A special approach to characterize the kinetics and efficiency of CoNPs formation in water medium and hybrid solutions using UV-Vis spectroscopy was implemented. The kinetic parameters of the CoNPs formation process as well as the yield, size, and morphology of nanoparticles in hybrid solutions and water medium at various concentrations of metal salt and hybrid were determined. The growth of both concentrations of reagents had a positive effect on the rate of formation of metal nanoparticles and their yield, but in all cases, the reduction process developed much slower in hybrid solutions compared to pure water. The morphology of the CoNPs/PIH nanocomposites was mainly represented by separate swollen hybrid particles containing metal nanoparticles with dav~3 nm.

A promising composite material is proposed to reduce the endogenous and exogenous contamination of chicken eggs with pathogenic microflora during their formation and storage. It is based on hybrid biocompatible and biodegradable silica/polyacrylamide nanocarriers containing small silver nanoparticles (dav=2.4±1.0 nm) that are orally administered to laying hens with drinking water. The features of the formation of nanosilver in hybrid carriers by borohydride reduction of a silver salt at its various concentrations in an aqueous solution have been studied. An interesting effect of the sharp appearance of the second surface plasmon resonance band in the UV-Vis spectra of a silver salt/hybrid mixture at a high salt concentration was found. This was explained by sharp structural changes in the hybrid carriers caused by the simultaneous growth of many AgNPs in them. It was assumed that the intensive growth of many AgNPs in one hybrid particle was accompanied by detachment of the grafted PAAm chains from the SiO2 surface due to the breaking of hydrogen bonds. The change in the state of the composite material under the influence of the pH of the solution, the concentration of nanoparticles, the presence of NaCl (as in a “physiological solution”), and visible light was studied by UV-Vis spectroscopy, potentiometric titration, and TEM. Nanosilver in carriers showed high stability with respect to most of these factors. The influence of the composite material on the clinical state of laying hens and important parameters of their eggs and blood was studied when it was administered orally with drinking water three times every 10 days at doses of 0.2 and 0.4 mg per chicken per day. A striking effect of selective endogenous accumulation of silver in eggshells has been revealed. This confirmed the penetration of the nanosilver composite into the circulatory system of chickens by passing through the digestive tract, absorption through the intestinal epithelium and further transport into the tissues of the chickens, including the oviducts, where protein and eggshell are formed. Such penetration did not cause a toxic effect on the body of laying hens.

A series of polymer/inorganic hybrids based on silica sol and polyacrylamide (SiO2-g-PAAm) with different number and length of PAAm chains was obtained by radical graft polymerization of acrylamide from the surface of SiO2. The main molecular and structural parameters of the hybrids, such as the chemical composition, average radius and charge of SiO2 particles, the number of grafts per one particle and their molecular weight, the average diameter and hydrodynamic volume of hybrid particles, and the thickness of the PAA layer, were determined. For this, elemental analysis, DTGA, static light scattering, viscometry, potentiometric titration, and TEM were used. The functional properties of hybrids as hydrophilic matrices in the in situ synthesis of nickel nanoparticles by borohydride reduction of metal ions from the Ni(NO3)2·6H20 salt in an aqueous medium have been studied. Using the method of UV-Vis spectroscopy and the developed original approach, the kinetics and efficiency of the formation of NiNPs in hybrid solutions were characterized, depending on the structure and concentration of the hybrid matrices and the concentration of the metal salt. An increase in the rate of accumulation and yield of NiNPs in solutions of all hybrids was found with an increase in salt concentration in the range of 0,010-0,078 kg·m-3, as well as a predominant decrease in the reaction rate with an increase in the concentration of hybrid matrices from 0,5 to 2,0 kg·m-3. It was shown that the structure of the hybrid matrices, determined by the number and length of PAAm chains, as well as the permeability of the grafted polymer layer, was one of the key factors affecting the formation rate and yield of NiNPs. It provided greater or lesser accessibility of the active groups of the "corona" and the inorganic "core" for metal ions and reducing agent molecules. Morphological studies of purified reduction products were carried out by TEM. Based on them, the main structural elements of highly dispersed NiNPs/SiO2-g-PAAm nanocomposites were established – swollen hairy particles of hybrids with small amorphous NiNPs (1,7±0,8 nm) included in the polymer "corona".

This review aims to provide a literature overview as well as the authors' personal account to the studies of Laponite® (Lap)/Polyethylene-oxide (PEO) based composite materials and their applications. These composites can be prepared over a wide range of their mutual concentrations, they are highly water soluble, and have many useful physico-chemical properties. To the readers' convenience, the contents are subdivided into different sections, related with consideration of PEO properties and its solubility in water, behavior of Lap systems(structure of Lap-platelets, properties of aqueous dispersions of Lap and aging effects in them), analyzing ofproperties LAP/PEO systems, Lap platelets-PEO interactions, adsorption mechanisms, aging effects, aggregation and electrokinetic properties. The different applications of Lap/PEO composites are reviewed. These applications include Lap/PEO based electrolytes for lithium polymer batteries, electrospun nanofibers, environmental, biomedical and biotechnology engineering. Both Lap and PEO are highly biocompatible with living systems and they are non-toxic, non-yellowing, and non-inflammable. Medical applications of Lap/PEO composites in bio-sensing, tissue engineering, drug delivery, cell proliferation, and wound dressings are also discussed.

The structure and thermophysical properties of polymer nanocomposite systems based on polyethylene glycol and organomodified montmorillonite were studied using the methods of X-ray structural analysis and differential scanning calorimetry. From the data of X-ray structural analysis, it was found that the optimal degree of delamination of montmorillonite, which corresponds to the maximum interlayer distance, occurs in 3-5 minutes. A further increase in the mixing time has no significant effect on the structural characteristics of the nanocomposite. On the basis of calorimetric studies, it is shown that the melting and glass transition temperatures, as well as the degree of crystallinity, reach critical values at 3 min of treatment, after which they remain unchanged. It was established that the time of extruder mixing is optimal. At the same time, the maximum intercalation takes place, which leads to an impact on the final functional characteristics of the polymer-organoclay system. It was established that extruder mixing during 3 min is optimal.

Використовуючи метод імпедансної спектроскопії, проведено дослідження електричних властивостей нанокомпозитів на основі поліпропіленгліколю та анізометричних нанонаповнювачів. Використання рівняння Міямото–Шибаями дало змогу розділити внески активаційного та неактиваційного механізмів перенесення зарядів у системах, наповнених лапонітом. Визначено критичну температуру, при якій відбувається зміна механізмів. За допомогою методу еквівалентних схем та теорії Макдоналда було встановлено, що в нанокомпозитах, які містять карбонанотрубки наявні два типи провідності – іонна таелектронна.

Double hydrophilic diblock copolymers based on asymmetric chemically complementary methoxypoly(ethylene oxide) and poly(acrylic acid) formed special micellar structures of the “cut” and “hairy” types with a complex “core” in aqueous solutions at pH < 5. These micelles have proven to be very effective, non-toxic, biocompatible, and biodegradable nanocarriers for the delivery of a poorly soluble vitamin E analogue, α-tocopheryl acetate, to sows and piglets. The obtained compositions of α-tocopheryl acetate with both types of micellar carriers showed high stability over time in a wide range of pH 3.5–9.0 and in physiological solution. However, in the case of “hairy” micelles, the developed “corona” of longer unbound segments of the polyacrylic acid block provided more reliable protection of the encapsulated drug molecules from the “salting-out” effect. The gradual release of the vitamin E analogue from both micellar nanocarriers into the aqueous and aqueous/salt medium under the action of the concentration gradient of α-tocopheryl acetate has been proved. The rate and efficiency of drug release were determined by the structure, morphology and stability of micellar carriers, as well as by the nature of the environment. The composition of α-tocopheryl acetate with one of the nanocarriers was tested in vivo on a group of sows as a dietary supplement. The positive effect of the micellar form of the drug on metabolic processes in sows, as well as on increasing the productivity of sows, stress resistance and safety of born piglets has been established.

Block copolymers comprising chemically complementary poly(ethylene oxide)/polyacrylamide have been evaluated as proton conducting materials. With this aim in mind, two series of block copolymers PAAm-b-PEO (DBC) and PAAm-b-PEO-b-PAAm (TBC) with the variable PEO-block length have been synthesized. Polymer electrolyte membranes (PEM) based on DBCs, TBCs and also their partially hydrolyzed derivatives (DBChydr and TBChydr respectively) were prepared by using a solution casting technique, and their ion (proton) conductivity was studied at the ambient temperature and at different relative humidity (RH). The rise in RH from 33% to 98% resulted in the increase in conductivity of DBC and TBC membranes up to 10−4 S∙cm−1. The study of the kinetics of the water absorption at 98% RH showed that the introduction of –COOH-groups into PAAm chains could accelerate the process of water absorption. The increase in conductivity of DBC and TBC membranes with the PEO-block lengthening has been noticed. This proved the significant contribution of oxyethylene chains in ensuring the conductivity. The reason for the application of DBCs and TBCs as potantial ion-conducting membranes have been discussed.

In this work, the effect of ultrasonic dispersion time on the structural and thermophysical properties of nanocomposites was studied. Model systems were made based on polyethylene glycol and montmorillonite. All samples had the same composition and filler content (5% by weight), the ultrasonic treatment time was from 5 to 12 minutes. The methods of wide-angle X-ray scattering and differential scanning calorimetry were used to establish the dependence of the properties of the systems on the dispersion time. Data analysis of the obtained results showed that the variation of ultrasonic dispersion time significantly affects the properties of polymer nanocomposites. As the mixing time increases, the interplanar distance of montmorillonite increases, which indicates an increase in the degree of intercalation of the polymer matrix. At the same time, the crystallinity of the nanocomposite decreases, which corresponds to the increase in the area of the polymer/filler boundary layer. The melting temperature of the nanocomposite increases with increasing dispersion time. This trend is a consequence of the complication of the thermal movement of polymer molecules due to the presence of a developed surface of the filler. It is shown that with an increase in the sonication time, the part of the immobilized amorphous fraction of the polymer increases. This is explained by the fact that the polymer intercalated in the interlayer space of montmorillonite loses its ability to cooperative movement, that is, to glass transition. It was established that the maximum improvement of system properties is observed at a dispersion time of 10 min. In this state, the montmorillonite particles are most stratified, which leads to the maximum increase in the area of the boundary layer. During further mixing, processes of aggregation of montmorillonite particles and destruction of polymer molecules occur, which leads to the loss of the desired properties of the nanocomposite. Finding the optimal mixing time of a polymer nanocomposite makes it possible to obtain the desired properties of systems with a defined composition.

The structure features and intercalation processes in oligoethylene glycol (OEG)-based systems and organoclay were studied using X-ray diffraction analysis. It is established that after the introduction of surfactants, the interlayer distance in montmorillonite (MMT) increased. This indicates the intercalation process of surfactant molecules into the interlayer space of the MMT. After introduction to polymer matrix the increase in the interlayer distance is observed. This indicates the intercalation of two monolayers of OEG and the formation of quasibilayer structures. It is shown that the structure of OEG-based systems significantly depends on the content of the nanofiller. Partial processes of intercalation are observed in OEG-organoclay nanocomposites.

A graft copolymer of poly(vinyl alcohol) and polyacrylamide (PVA-g-PAAm) with interacting main and grafted chains was synthesized by radical matrix polymerization of PAAm from the PVA backbone in an aqueous medium. Its basic molecular parameters including the number and length (molecular weight) of grafts were determined using elemental analysis, DTGA and viscometry. The copolymer macromolecules formed special monomolecular micelles of elipsoidal shape and length ~18-64 nm in aqueous solutions due to the formation of intramolecular polycomplexes between the main and grafted chains. This copolymer was used as a hydrophilic matrix for the in situ synthesis of nickel nanoparticles (NiNPs) in aqueous solutions.On the basis of UV-Vis spectroscopy, an original and simple method for monitoring the kinetics of the formation and yield of metal nanoparticles in systems in which a surface plasmon resonance band does not appear has been proposed and implemented. Using this approach, the kinetics of borohydride reduction of Ni-salt to NiNPs in pure water and PVA-g-PAAm solutions was studied depending on the concentrations of Ni-salt and copolymer matrices. An increase in the initial rate of accumulation and yield of NiNPs with an increase in the concentration of Ni-salt and a decrease in both parameters in copolymer solutions in comparison with pure water was established. At the same time, the accumulation rate and NiNP yield in a complex way was depended on the matrix concentration that was determined by the ratio of such factors as a decrease in the diffusion rate of NaBH4 molecules in copolymer solutions and the accumulation of Ni2+-ions in matrix particles due to complexation with active chemical groups at the first stage of reduction process. The morphology and main structural elements of the NiNPs/PVA-g-PAAm composition were revealed using TEM. It was shown that the in situ synthesis of NiNPs in copolymer matrices was accompanied by the “detachment” of PAAm grafts from the main PVA chains and led to the appearance of two new structures, such as “hairy coils” and “hairy rods”, containing small spherical NiNPs (d~0,5–12,0 nm) in isolated and chain states, respectively. The appearance of the latter structures was explained by the formation of coordination complexes of Ni2+-ions with active groups of both PVA and PAAm chains at the first stage of the reduction reaction.

Triblock copolymers comprising chemically complementary poly(ethylene oxide)/polyacrylamide (TBC) and their partially hydrolyzed derivative (TBChydr) were investigated as possible ion-conducting membranes for Li-ion batteries (LBs), dye-sensitized solar cells (DSSCs) and fuel cells (PEFCs). Two TBC samples consisting PEO blocks of variable block length (MnPEO = 6.10(4) and 3.5.10(4) kDa) were synthesized and used for these purpose. It was noticed that ionic conductivity of TBC membranes increases with PEO block lengthening from 6.2.10(-11) to 3.2.10(-9) S.cm(-1). The introduction of additional ionic groups -COOH in polyacrylamide block of TBC has a positive effect on the conductive characteristics of copolymer membranes. The ionic conductivity of TBC membranes filled with LiPF6 increases with increasing of salt content.

ABSTRACT A grafted polymer/inorganic hybrid combining the properties of silica nanoparticles (Rav = 7.7 nm) and polyacrylamide (SiO2-g-PAAm) was synthesized, characterized and used as a matrix for in situ synthesis of silver nanoparticles (AgNPs). In the “core”-“corona” hybrid nanostructures, PAAm grafts were additionally bonded to the silica surface by H-bonds. The reduction of Ag+-ions in SiO2-g-PAAm solutions occurred in PAAm “coronas” with a high rate and yield. This led to the formation of spherical AgNPs of 3–9 nm in size in swollen hybrid nanostructures. Various aspects of the possible use of the AgNPs/SiO2-g-PAAm composition for disinfecting fish aquariums/ponds, including biological risks, were studied. GA

Asymmetric block copolymers PAAc-b-PAAm (DBC) and PAAm-b-PAAc-b-PAAm (TBC) comprised poly(acrylic acid) and polyacrylamide have been evaluated as potential vehicles for doxorubicin (Dox) targeted delivery. The processes of Dox release from the DBC and TBC micelles under the influence of the drug’s concentration gradient and various surrounding medium, such as NaCl solution and aqueous medium at pH= 5.75 and 9, were examined. The previously established tendency to significantly reduce the Dox encapsulation degree by the DBC and TBC micelles at the increase of the size of their “corona” was fully confirmed (Kunitskaya et al. 2018). Noticed that PAAm block’s lengthening complicated the Dox release against all environments under study. It was revealed that micelles which easily and effectively encapsulate Dox as easily "give away" the drug during dialysis. Increasing pH of the DBC and TBC solutions to 9 prevented drug release. It can be stipulated by enhancing interaction between Dox and micellar “core” caused by the ionization of –COOH groups contained in PAAc blocks. Preliminary biological investigations in vitro against human T-leukemia cells demonstrate essential anticancer activity of Dox/DBC and Dox/TDC compositions, as compared to pure Dox.

Abstract Polymer/inorganic hybrid based on silica sol and grafted polyacrylamide chains (SiO2/PAAm) was obtained by radical graft polymerization of acrylamide “from” unmodified silica surface. Its main parameters: RavSiO2, MvPAAm and N (the number of grafts per inorganic particle) were determined using static light scattering, elemental analysis, DTGA and viscometry. The hybrid was used as effective matrix in synthesis of NiNPs by borohydride reduction of Ni2+-ions in aqueous medium. A special approach to characterizing the kinetics and efficiency of NiNPs formation in pure water and hybrid solutions using UV-Vis spectroscopy was proposed and implemented. Due to this, an increase in the rate of accumulation and yield of NiNPs both in pure water and hybrid solutions with an increase in the Ni-salt concentration was established. In addition, a decrease in this rate with an increase in the concentration of hybrid matrices was found, as well as a slowdown in the reduction reaction in hybrid solutions compared to pure water. It was shown by TEM that the separate structural elements of the NiNPs/hybrid compositions are the swollen “hairy-type” hybrid structures with a size of ∼8.0–49.2 nm containing small (∼1.0–5.4 nm) NiNPs in PAAm “coronas.”

Synthesis, features of structural organization and behavior in aqueous solution of amphiphilic reactive aprotic cationic oligomeric ionic liquids obtained on the basis of a mixture of oligomeric amino- and hydroxyl-containing silsesquioxanes were considered. The dependence of the glass transition temperature, the value of ionic conductivity, self-organization in dilute aqueous solutions and the ζ-potential on the length of the alkyl substituent near the quaternary nitrogen atom in the composition of the synthesized compounds was shown. It was found that quaternization of the tertiary nitrogen atom of the starting oligomer causes a sharp decrease in the glass transition temperature. The value of the latter increases with an increase in the length of the hydrophobic alkyl fragments due to their association. In this case the ionic conductivity under anhydrous conditions decreases and at temperatures above 100°C drops by almost an order of magnitude. The maximum conductivity was reached for the oligomeric ionic liquid with the short alkyl chain and its value was 10-3 S/cm at 120oC. In dilute aqueous solutions the synthesized oligomeric ionic liquids with the short alkyl chain form aggregates with an average size of 100 nm while increasing the length of the alkyl chain prevents aggregation of silsesquioxane nuclei and leads to formation of unimolecular micelles with an average size of 3 nm