Novel magnetoactive thin film composites based on silicone elastomer with nano-structured iron fillers have been synthesized. Atomic force microscopy studies have established these composites surface topography unique sensitivity to restructuring induced by the atomic force microscope probe. Application low external magnetic field also resulted in changing the initial composites surface wrinkled structure. Scanning electron microscopy research allowed determine the filler agglomerates average size from about 100 nm to 5 μm and their distributions in the polymer matrix. These composite systems with variable surface properties, possess tunable microstructure morphology as a result of controlling small external influences. Such magnetoactive thin film smart surfaces with dynamic wrinkles can find wide practical applications in tunable optical and electronic devices with responsive microstructures.

The paper deals with an experimental and theoretical study of bending deformation of a rod-shaped magnetic elastomer, consisting of a soft polymer with embedded micron-sized magnetic particles, under the action of a transverse magnetic field. Initially, the sample is situated on a horizontal substrate between poles of an electromagnet, creating a vertical magnetic field. One end of the magnetic rod is fixed; the other one is free. The sample's upward bending takes place when the field exceeds some threshold value B-1. While the field decreases, the deformation disappears when the field becomes less than the second threshold value B-2, which is significantly less than B-1. So, the plot of the bending versus magnetic field presents a wide hysteresis loop. Two types of deformations are detected experimentally and explained theoretically: the monotonic increase of the deformation from the fixed end of the sample to the free one, and the non-monotonic bend, with a maximum. Analysis shows that the spontaneous deformation can take place only if the field increases upward and the ponderomotive force acting on a filament segment dominates over gravity.

Magnetoactive (aka magnetorheological) elastomer composites, which are elastic polymer matrices filled with micron-sized particles of a ferromagnet, are a novel type of magnetically controllable material. In addition to their complex magnetomechanical behavior, magnetoactive elastomers, as conducting substances, possess electrical resistivity that is highly sensitive to both mechanical stress and the applied magnetic field. Here, we present a study on the response of such composites to pulse mechanical or magnetic perturbations. Remarkably, a transient electric process induced by any of those stimuli is always non-monotonic. The electric current measurements reveal that before settling at the new equilibrium level, the resistivity always undergoes a substantial jump-up independently on the sign of the perturbation: a pressure on/off or the field on/off. The main goal of the work is to register the encountered effect in detail.

Magnetoactive, also known as magnetorheological, elastomer is a composite material based on an elastic polymer filled with magnetic particles. The specifics of its deformation under the influence of magnetic fields have been the subject of this research. For instance, in non-homogeneous fields the degree of strain may reach hundreds of percent whereas magnetized samples containing high-coercivity (hard magnetic) components can suffer deformations occurring in a complex way. In addition to that, a sample responds to an external field with an increased roughness of its surface thus becoming more hydrophobic. The material also increases its stiffness by ten folds. These facts suggest that this elastomeric composite may be considered potentially useful for such areas as robotics and controllable damping units.

Magnetoactive (aka magnetorheological) elastomer is a composite material consisting of an elastic matrix and magnetic filling substance. A study dedicated to the relationship between its viscoelastic parameters and the strength of the external magnetic field has been done. Under the influence of a field, the material can demonstrate elasticity and viscosity increased by ten folds. The elastic properties of the composite remaining under those conditions heavily depend on the degree of deformation of the sample. Thus, this type of magnetic composite is a prospective material for being used as the working body in controllable dampers.

A magnetoactive (or magnetorheological) elastomer is a composite material consisting of an elastic matrix and a magnetic filler. The elastic properties of the material under the action of an external magnetic field are studied. The elasticity of the composite grows by orders of magnitude under the action of a magnetic field. The elastic properties of the material in a magnetic field depend strongly on the level of its deformation. This type of unique magnetic composite is a promising candidate for the working body in controllable dampers.

Впервые методом функционала плотности в базисе 6-311++G2df, 2p в приближении гибридного функционала M06-2X обнаружено неплоскостное (объемное) строение сульфохлоридных групп в хлорсульфированном полиэтилене. Установлено, что особенности их структуры оказывают прямое влияние на согласованный механизм термической деградации, сопровождающейся образованием углерод-центрированного макрорадикала R•n и атома хлора Cl•. Экспериментально доказано участие этих радикалов в процессах структурирования макромолекул при одностадийном получении термопластичных вулканизатов.

Silicone-based elastomer containing Nd–Fe–B-alloy particles garnished with a small portion of nickel grains has been studied for the capability to conduct alternating current. The observations suggest that the presence of nickel expands the variation range of the conductivity and magnetocapacitance in external magnetic fields. In addition, the composite demonstrates the memory of primary magnetizing manifesting itself as certain specific features of the hysteresis loops depending on the polarity of the external magnetic field.

For the first time using the density functional method in the 6-311++G(2df, 2p) basis set in the M06-2X hybrid functional approximation the nonplanar (dimensional) structure of sulfonyl chloride groups in chlorosulfonated polyethylene has been revealed. It has been shown that their structural features have a direct influence on the concerted mechanism of thermal degradation accompanied by the formation of a carbon-centered macroradical R_n^∙ and a chlorine atom Cl•. The participation of these radicals in the processes of crosslinking macromolecules in the single-step production of thermoplastic vulcanizates has been experimentally verified.

Anisotropic magnetically active elastomers based on polydimethylsiloxane and magnetic particles of different chemical natures, shapes, and sizes have been synthesized. A comparative analysis of their mechanical properties (elastic modulus, strength, and elongation at break) has been performed depending on the mutual orientation of the internal structure, formed by magnetic filler particles during the synthesis of the composite in a magnetic field, and the direction of the external mechanical force applied to stretch the samples. The anisotropy of mechanical properties is most pronounced in composites based on anisometric particles, needle-like and plate-like. The highest values of anisotropy coefficient of elastic modulus are observed in the composite containing plate-like iron microparticles; for this composite, the ratio of the elastic moduli in the directions parallel and perpendicular to the internal structure reaches a value of five. The use of magnetic filler and its orientation by means of magnetic field is an effective method for creating polymer composites with anisotropy of mechanical properties.

Nanoplatforms applied for the loading of anticancer drugs is a cutting-edge approach for drug delivery to tumors and reduction of toxic effects on healthy cells. In this study, we describe the synthesis and compare the sorption properties of four types of potential doxorubicin-carriers, in which iron oxide nanoparticles (IONs) are functionalized with cationic (polyethylenimine, PEI), anionic (polystyrenesulfonate, PSS), and nonionic (dextran) polymers, as well as with porous carbon. The IONs are thoroughly characterized by X-ray diffraction, IR spectroscopy, high resolution TEM (HRTEM), SEM, magnetic susceptibility, and the zeta-potential measurements in the pH range of 3-10. The degree of doxorubicin loading at pH 7.4, as well as the degree of desorption at pH 5.0, distinctive to cancerous tumor environment, are measured. Particles modified with PEI were shown to exhibit the highest loading capacity, while the greatest release at pH 5 (up to 30%) occurs from the surface of magnetite decorated with PSS. Such a slow release of the drug would imply a prolonged tumor-inhibiting action on the affected tissue or organ. Assessment of the toxicity (using Neuro2A cell line) for PEI- and PSS-modified IONs showed no negative effect. In conclusion, the preliminary evaluation of the effects of IONs coated with PSS and PEI on the rate of blood clotting was carried out. The results obtained can be taken into account when developing new drug delivery platforms.

As a result of a study carried out on the capability of magnetoactive elastomer filled with particles obtained from carbonyl iron and nickel by the mechanochemical method to conduct direct current, there were obtained voltampere characteristics corresponding to different magnetic fields. In the whole, it has been demonstrated that such a composite material is capable of changing its conductivity under the influence of magnetic field and hydrostatic load by 5-6 orders of magnitude. The material also exhibits certain features of a semi-conductor which gives some grounds to suppose that electron transfer occurring among the particles might be conditioned by a tunneling mechanism. The possibility to carry out the DC measurements was determined by the good magnetic properties and high electric conductivity of the filling substance. Magnetoactive elastomer of this type is a prospective material for designing sensors for mechanical pressure, magnetic field, and strain.

Viscoelastic properties of magnetoactive elastomers with spherical and plate-shaped filler have been studied. Four series of samples based on silicone elastomer and carbonyl iron microparticles have been prepared. A series of samples with a concentration of magnetic filler from 30 to 60 wt

New anisotropic magnetically active elastomers using carbonyl iron micrometer size ferromagnetic fillers in the silicone matrix were synthesized. Samples with orientation of the outer magnetic field strength vector applied in perpendicular or in parallel direction to the mold surface during polymerizing composite mass were investigated. These composites surface structure was studied using the topography and phase contrast images in the atomic force microscope. Significant surface magnetodeformation effects in these composites, comparable with Terphenol-D, under the application of small external magnetic fields were visualized by atomic force microscopy methods. The transverse magneto-deformation constant value was determined for both samples. Greatly periodically deformed surface structure background was observed in these composites. The obtained experimental results analysis show that significant component of these materials unique properties is due to the ferromagnetic fillers restructuring in both isotropic and anisotropic magnetically active composites under small external magnetic fields influence.

New anisotropic silicone magneto active composites have been synthesized and investigated. A significant increase in the composites elastic moduli depending on the ferromagnetic carbonyl iron filler concentration and filler orientation functions was established. These materials surface structure and filler sizes were visualized by atomic force microscopy. The investigated composites elastic strengthening nature is discussed.

Синтезированы анизотропные магнитоактивные эластомеры на основе полидиметилсилоксана и магнитных частиц разной химической природы, формы и размера. Проведен сравнительный анализ их механических свойств (модуля упругости, прочности и удлинения при разрыве) в зависимости от взаимной ориентации внутренней структуры, формируемой частицами магнитного наполнителя при синтезе композита в магнитном поле, и направления внешней механической силы при растяжении образцов. Анизотропия механических свойств наиболее ярко проявляется в композитах на основе анизометричных частиц – игольчатых и пластинчатых. Наибольшие значения коэффициента анизотропии упругости наблюдаются у композита, содержащего пластинчатые микрочастицы железа, для него отношение модулей упругости в параллельном и перпендикулярном внутренней структуре направлениях достигает пяти. Использование магнитного наполнителя и его ориентирование при помощи магнитного поля является эффективным методом создания полимерных композитов с анизотропией механических свойств.

The magnetoelastic material samples in compression tests are investigated. The studied materials rheological properties are carried out on an automated testing machine. Compressive moduli changes diagrams depending on deformation values up to limiting extreme values are plotted. Transition ranges from linear to nonlinear, longitudinal compression moduli, depending on the specimen compression degree, were fixed. Repeated tests on specimens showed a decrease in the compression moduli by several times. In revealing rheological properties the investigated materials shape memory effect is demonstrated.

New anisotropic silicone magnetoactive composites were synthesized and studied. The surface structure and filler microdimensions in these elastomers were determined by electron microscopy. The atomic force microscopy use made it possible to determine significant surface deformations and magnetostrictive effects when small external magnetic fields are applied to the composites. Mössbauer spectroscopy on iron isotope nuclei made it possible to identify the fillers hyperfine parameters.

В статье рассматривается ряд проблемных вопросов, возникающих при розыске осужденных, уклоняющихся от отбывания уголовных наказаний длительное время. Предлагаемые в статье варианты действий в подобных ситуациях связаны с изменениями законодательства Российской Федерации, которые влияют на правовой статус осужденных, и, несмотря на их уклонение от уголовного наказания, дают возможность пересмотра приговоров и прекращения розыска. Методологическую основу исследования составили наблюдение, изучение документов и результатов деятельности, анализ, синтез. В ходе исследования рассмотрены возможные варианты прекращения уголовного преследования в отношении осужденных: при декриминализации преступных деяний, амнистии, истечении сроков давности обвинительного приговора, что может способствовать также прекращению их розыска. Научная новизна и практическая ценность данной работы состоит в обосновании и необходимости применения предлагаемых процедур для изменения правового статуса разыскиваемого осужденного путем использования действующих норм законодательства Российской Федерации. Полученные результаты позволят сократить остаток неразысканных осужденных, при этом обеспечить конституционные права и гарантии данных лиц, несмотря на их уклонение от уголовного наказания. The article deals with a number of problematic issues that arise when searching for convicts who evade serving criminal sentences for a long time. The options proposed in the article in such situations are related to changes in the legislation of the Russian Federation that affect the legal status of convicts, and, despite their evasion of criminal punishment, provide an opportunity for review of sentences and termination of the search. The methodological basis of the study was observation, study of documents and results of activities, analysis, synthesis. In the course of the study, possible options for terminating criminal prosecution against convicts were considered: with the decriminalization of criminal acts, amnesty, expiration of the statute of limitations for a guilty verdict, which may also contribute to the termination of their search. The scientific novelty and practical value of this work lies in the substantiation and necessity of applying the proposed procedures to change the legal status of a wanted convict by using the current norms of the legislation of the Russian Federation. The results obtained will reduce the remainder of unidentified convicts, while ensuring the constitutional rights and guarantees of these persons, despite their evasion of criminal punishment.