This study evaluated the feasibility of using uncoated iron (II, III) oxide nanoparticles (IONP) obtained by electric explosion of wire in air for labelling living mesenchymal stromal cells and their subsequent visualization by magnetic resonance imaging (MRI) using 1.5T clinical MRI scanners. The uptake of uncoated IONP by MSC was demonstrated for the wide range of IONP concentration in the cell culture medium. The cells did not change their proliferative activity, viability, and the set of surface markers. IONP obtained by electric explosion of wire in an atmosphere of air had a shape close to spherical. The size of nanoparticles varied from 14 to 136 nm according to dynamic lateral light scattering, laser diffraction, and transmission electron microscopy. Particles up to 136 nm comprised 75%, and particles less than 36 nm --- 10% of the IONP powder. A wide range of particle sizes made it possible to select MRI parameters suitable for labelled cells detection in animal tissues both in the T2 mode and in the T1 relaxation mode.

The possibilities of creating a monolithic lenticular lens with an increased focal length capable of forming a view zone of an autostereoscopic image at a distance of at least 3–7 m away from the screen, are studied. At the optimal ratio between the refractometric, viscosity, and chemical parameters of liquid composition, the use of polymerizable photocurable acrylic compositions based on oligourethane acrylates as the immersion medium gives rise to an immersion-formed polymer with optical parameters ensuring the desired focal length of a monolithic lenticular lens.

Изучено влияние параметров сетки пространственно сшитых полиакриловых оптически прозрачных матриц на процесс генерирования поверхностного плазмонного резонанса наночастиц золота, образующихся при облучении раствора соли золота Au3+ в жидкой акриловой композиции. При УФ-облучении раствора одновременно происходит фотовосстановление золота и фотоинициированная полимеризация акрилатов с образованием прозрачных бесцветных пленок, в которых при последующем воздействии света и(или) тепла генерируется полоса поглощения вблизи 550 нм, обусловленная плазмонным резонансом наноразмерных частиц металла. В процессе фотовосстановления соли золота в матрице олигоуретанакрилатных композиций с близким строением олигомерного блока параметры пространственной сетки – межузловое и межцепное расстояния – влияют на скорость генерирования наночастиц золота, но не на предельное значение оптической плотности полосы плазмонного резонанса наночастиц. Полиакрилатные матрицы могут являться регистрирующей средой для оптической записи информации.

The effect of network parameters of three-dimensionally crosslinked polyacrylic optically transparent matrices on the generation of surface plasmon resonance of gold nanoparticles forming during irradiation of Au3+ salt solutions in a liquid acrylic composite is studied. During the UV irradiation of a solution, the photoreduction of gold and the photoinitiated polymerization of acrylates proceed simultaneously to form transparent colorless films in which, after subsequent light and/or heat treatment, an absorption band near 550 nm that corresponds to the plasmon resonance of nanosize metal particles is generated. During the photoreduction of gold salt in matrices of oligo(urethane acrylate) composites with similar structures of the oligomeric block, the parameters of the three-dimensional network—the internodal and interchain distances—affect the rate of generation of gold nanoparticles but not the limiting value of optical density for the plasmon-resonance band of nanoparticles. Polyacrylate matrices may serve as a registering medium for optical data recording.

Supercritical fluid impregnation was used to perform matrix isolation of spiroanthroxazine (SAO) photochromic molecules in halogenated polymer films (polyvinylchloride and tetrafluoroethylene copolymer with vinylidene fluoride). An excited (colored) SAO form not relaxing to the ground (colorless) state was stabilized in polymers. Such a long-lived excited SAO form could exist as an isomer of the B form (B535 with an absorption band at λmax = 535 nm) in the fluorinated polymer matrix, for which the absorption maximum was shifted by more than 75 nm to the blue, and as the B form with a small admixture of the B535-form (in polyvinylchloride).

The effect of the network density of spatially crosslinked polyacrylic transparent matrices and the conditions of their impregnation with a photochromic compound via the use of supercritical carbon dioxide on the concentration of the introduced photochromic compound of the spiroxazin family is studied. The concentration of impregnated filler in a matrix is shown to increase with increases in the interjunction distance (below a certain level) and network chain flexibility as well as with increases in the temperature and pressure of the impregnation process. Impregnation in rigid networks occurs only in surface layers, whereas, in an elastic network, impregnation occurs in the entire volume of a sample. Matrices based on oligourethanemethacrylates are characterized by a good thermodynamic affinity toward spiroxazin photochromic compounds, a fact that makes it possible to increase the concentration of photochromic compounds in the matrix up to 3 wt % under conditions of supercritical impregnation. The photochromic characteristics of an impregnated compound are shown to be preserved in samples.

The possibility of generation of a surface plasmon resonance by gold nanoparticles in a 3D network polymer matrix upon irradiation of a liquid acrylic composition containing a dissolved Au3+ salt is demonstrated for the first time. UV-irradiation of the solution simultaneously causes gold photoreduction to Au0 and acrylate photopolymerization. The possibility of preparing transparent colorless films that, when heated or exposed to light, give rise to a visible-spectrum absorption band belonging to a plasmon resonance of metal nanoparticles is demonstrated. The intensity and position of the plasmon resonance band depend on the parameters of the 3D polymer network, chemical structure of the oligomer, type of the support, and conditions of formation of Au0 particles. The formation of reduced gold nanoparticles responsible for the plasmon resonance band occurs more effectively in low-density networks with a large interchain length and containing oligomer block capable of complexation with the metal. The formation of nanoparticles is affected by the chlorine-containing products of the reduction of the gold salt.

The impregnation of thermoplastic polymers (polyethylene, polypropylene, polymethyl methacrylate, and polycarbonate) with photochromic compounds from the class of indoline spirooxazines in supercritical carbon dioxide (SC-CO 2 ) was studied. The concentration of the photochrome and the kinetics of decolorization of its colored form depended strongly on the type of the polymer matrix and the structure of spirooxazine. The introduction of 1,3′,3′-trimethylspiro(indoline-2′,3-3H-anthraceno[2,1-b][1,4]oxazine) (SAO) into polycarbonate caused anomalous stabilization (the prolonged conservation of the excited colored form of SAO in the polymer matrix). In contrast to other photochrome-polymer pairs, after supercritical impregnation into polycarbonate, at least 10% of all SAO molecules were in the colored form, which was highly stable and did not decolorize after 150 days; the rest of the impregnated SAO molecules were localized in the matrix as individual molecules, partially colorized after matrix relaxation, or nanocrystals of characteristic sizes ∼10–20 nm. The mechanisms of the anomalous stabilization of the colored SAO form in the polycarbonate matrix are discussed.

Various thermoplastic polymers (polyethylene, polypropylene, PMMA, polycarbonate) were impregnated with spiroxazine photochrom (-1,3,3-threemethylspyro (indoline-2,3-3Нantrazeno[2,1-b] [1,4] oxazin) (SAO) dissolved in supercritical CO2 SAO molecules have usually stable unexcited form (A) that transfers to unstable “colored” form (B) under the action of UV light. It was found that, unlike other polymers under study, the supercritical fluid (SCF) impregnation of polycarbonate (PC) with SAO causes the anomalous stabilization of its colored form B. The bleaching time of SAO in PC after its photoexcitation (900 с) is two orders of magnitude higher than that in polypropylene. Moreover, after supercritical fluid impregnation of PC up to 20% of SAO is originally formed in colored form, which is not bleachable for 250days (the whole period of observation), i.e. is extremely stable. The temperature and pressure effects on SAO concentration in different polymer matrixes were measured. At least some part of SAO incorporated into the polymeric matrix forms nanocrystals of ~10-20 nm size. Possible mechanisms of the observed effect of the anomalous stability of colored SAO form trapped in the polycarbonate matrix after its SCF are discussed.

A number of new polymeric electrolytes based on an oligo(urethane dimethacrylate)-poly(propylene glycol monomethacrylate) composition and liquid organic electrolytes, such as a solution of LiClO4 in gamma-butyrolactone, a solution of LiBF4 in the same solvent, and a solution of LiPF6 in a mixture of ethylene carbonate-dimethyl carbonate (1 : 1, vol/vol), were synthesized and studied. Electrolyte films were prepared by the photocure of solutions of the above components that were preliminarily applied onto a fibrous PP separator. The structures of the electrolytes thus prepared and of the original separator were examined by scanning electron microscopy. The relationship between the electrochemical properties of electrolytes with various lithium salts and the stability of these salts under the conditions of synthesis of polymeric electrolytes was established. It was shown that the decomposition of LiPF6, affording an insoluble LiF and a gaseous PF5, is responsible for a hi-h charge-transfer resistance at the lithium electrode interface.

Novel polymer gel electrolytes (PGE) based on a composition of oligourethane methacrylate, polypropylene glycol monomethacrylate, and 1 M solutions of LiClO 4 or γ in LiBF 4 -butyrolactone or LiPF 6 in ethylene carbonate/dimethyl carbonate (1 : 1 by volume) are synthesized and studied. The electrolyte films are solidified from liquid PGE solutions by irradiating the latter with UV light. Impedance spectroscopy shows PGE to have conductivity of about 3.0 × 10 –3 S cm –1 at room temperature. To enhance mechanical strength of PGE, the electrolyte solutions are applied onto a fiber polypropylene separator and then photosolidified. The temperature dependences of the bulk conductivity and the charge transfer resistance through the Li/PGE interface are studied. The best PGE is that based on a 1 M LiClO 4 solution in γ-butyrolactone containing 20 wt % of the polymer composite.

The phase state and interdiffusion in the blends of a flexible oligo(urethane methacrylate) and homologous series of dimethacrylic monomers were studied by the optical wedge method. It was shown that, at T > 20degreesC, all the tested blends are characterized by an unlimited compatibility of the components. The diffusion behavior of the studied systems obeys laws common for the majority of binary blends of low-molecular-mass compounds and systems of the polymer-low-molecular-mass compound type. The substitution of a methacrylic group by an acrylic moiety is accompanied by acceleration of the diffusion processes. The relationship between interdiffusion coefficients and molecular masses of dimethacrylic monomers is satisfactorily described by the equation D-V = K[M](-b), whose parameters K and b vary with temperature and the concentration of components.

Abstract The analysis of curing process of oligoesteracrylate blend system is carried out using the Avrami model.