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Background and Objectives: In recent years, the attention of the scientific community has been attracted by cerium(IV) oxide nanoparticles (CeO2 NPs), which demonstrate great potential for use in biomedicine due to their unique biological properties such as antioxidant and antibacterial activity. The development of biomaterials that combine the properties of polymers and the unique characteristics of CeO2 NPs opens up new horizons for applications in biomedicine. A thin layer of polymers preserves the catalytic activity of cerium oxide without blocking the path of electronic charge transfer on the surface of nanoparticles. The relevance of the development of CeO2 NPs with a polymer shell lies in the fact that polymers can bind to various medicinal and bioactive substances, becoming drug carriers. This work describes the preparation of CeO2 NPs with various polymers in order to study how the composition and structure of the polymer affect the size and charge of the resulting nanoparticles. The variability of the properties of CeO2 NPs will make it possible to test them for the encapsulation of other substances, including drugs, in order to identify optimal polymers. Materials and Methods: Cerium(III) nitrate hexahydrate Ce(NO3)3 · 6H2O was used as a precursor for the synthesis of CeO2 NPs. Four different polymers were used for the syntheses: polyacrylic acid (PAA), polyethylene glycol (PEG), poly(isobutylene-alt-maleic anhydride) (PIMA). The synthesis was carried out in ammonium hydroxide (28–30%). CeO2 NPs with a polymer shell were obtained by chemical deposition. Polymer solutions were prepared and mixed with a 1 M solution of Ce(NO3)3. With continuous stirring, the mixture was added to the ammonium hydroxide solution, after which ethanol was added and left under stirring for 24 hours at room temperature. Results: We have presented the synthesis of cerium oxide nanoparticles in the presence of polymers of various compositions and molecular weights to study their effect on the structure and size of nanoparticles. During the synthesis, it has been revealed that the optimal concentration of cerium(III) nitrate for syntheses is 1 M. The influence of the environment on the possible agglomeration of nanoparticles during purification and further storage has been studied. The best media for storing and purifying nanoparticles are water and phosphate-buffered saline. The size and morphology of the resulting polymer-coated CeO2 NPs have been studied by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and dynamic light scattering (DLS). TEM images show nanocrystals measuring about 10 nm in all four samples. SEM images show the presence of particles with a size of about 20–30 nm in all four samples. DLS analysis has shown that the smallest particles were formed with polyacrylic acid and poly(isobutylene-alt-maleic anhydride). Conclusions: The results of the study have demonstrated that for the synthesis of CeO2 NPs with a polymer coating it is better to use PAA and PIMA polymers since smaller particles are formed. It has been found that it is optimal to use 1 M Ce(NO3)3 for syntheses, and the best media for purification and storage of CeO2 NPs are water and FSB.

The paper proposes a novel approach to the construction of actuators for automation and robotics based on the use of new electroactive polymer materials – swelling hydrogels. The hydrogel pH-sensitive materials containing two polymer components, crosslinked polyacrylic acid and polyvinyl alcohol, are obtained. A procedure for the synthesis of hybrid hydrogel is described, and the achieved values of their characteristics, degrees of swelling in water and water solution of salt, are given. A method of hydrogel elements preparation with a specified geometric configuration was developed, and cylindrical and also ring-shaped samples were prepared. Mechanical properties of the prepared hydrogels at compression were measured. It is shown that the hybrid hydrogels exhibit higher strength and elasticity than the one-component polyacrylic acid hydrogels obtained by the same method. An actuator design is proposed with a hydrogel as a controlled element. An experimental layout of such actuator was constructed. The stability of material characteristics was determined, and methods for the electrodes fixation and electric current supply were developed. It was found that ring-shaped samples of hydrogels demonstrate electromechanical response – compression when electric current passes through their cross section. This fact was the evidence that these hydrogels can be used as a linearly operating generator of mechanical force. It is shown that this effect is more pronounced for samples swollen in water solution of sodium sulfate rather than in distilled water.

The aim of the article is to determine the influence of electroconductivity, electric current voltage, interelectrode spacing and rheological characteristics of solutions on the structure of non-woven materials and mechanical properties of the materials. When studying the influence of ion forming additives on the process of electrospinning the formation of droplets is revealed when adding the 1 % NaCl. To make faster the fiber production without impairing the quality it is advisable to use 0.2 %–1 % of ion additive. The results show that for optimum fiber forming stable interelectrode gap spacing is 100–200 mm, the voltage of 20–30 kV. At a temperature of 14–17 ºС solution viscosity changes slightly. By increasing the temperature to 25 ºС and above there is a significant drop in viscosity. Hence by temperature increasing more concentrated polymer solutions with a constant viscosity can be used to increase productivity. Analysis of the resulting materials structure shows that the obtained fiber thickness of 60–110 nm with the presence of droplet sizes ranges from 200 nm to 1800 nm.

The aim of this work is to determine the effect of polyvinylpyrrolidone, polyacrylic acid, acrylic and methacrylic acid compositions on the swelling polymers with PVA, as well as the influence of environment, close to the body (temperature, saline) on swelling as a parameter that determines the subsequent dissolution of the sample in the wound, lasting up to 10 days and it is difficult to control. As a result of experimental studies found that the use of polyacrylic acid and polyvinylpyrrolidone is most preferred to generate multifunctional composite materials based on polyvinyl alcohol. The quantitative values of the reduced components and their influence on the properties of the developed material. Found that swelling occurs in saline at a higher rate and to a greater degree of swelling parameters are found which allow to consider the influence on the behavior of the environment of the body of biodegradable polymer materials.