The photophysical properties of poly 2,2' (1 dodecyl carbazole 4,7 yl) 6,6' (oxy) bis (4 phe nylquinoline) in a solution, as a film, and in a poly(methyl methacrylate) or poly N vinylcarbazole host matrix have been studied. Considerable positive solvatochromism in the photoluminescence spectra, com pared with solvatochromism in the absorption spectra, indicates that the dipole moment of the donor-accep tor complex increases in the excited state. Calculations show that the dipole moments of the complex in the ground and excited states differ by more than an order of magnitude. Upon transition to films, photolumi nescence is observed in the entire visible spectral range (white luminescence). The intensity of the white lumi nescence grows by an order of magnitude when the polymer is dispersed in a poly(methyl methacrylate) matrix. The integrated photosensitivity and parameters of the photogeneration process (quantum yield of carrier photogeneration, quantum yield of free carrier formation, and thermalization radii) have been determined.

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Submicron-and micron-scale structures of composite hydrogels based on bacterial cellulose (BC) and polyacrylamide were studied by spin-echo small-angle neutron scattering (SESANS) and cryo-scanning electron microscopy (cryo-SEM). These hydrogels possessing the structure of interpenetrating polymer network were synthesized via free-radical polymerization of acrylamide carried out in the pellicle of BC swollen in the reaction solution. No neutron scattering was observed for the samples swollen in heavy water to the equilibrium state, but the SESANS signal appeared when TbCl 3 salt was added to the solvent. It is the unusual effect, which may be very helpful for SESANS studying of other hydrogel systems. The SESANS dependences obtained for these samples revealed the anisotropy of mesostructure for the hydrogels under investigation. Density inhomogeneities on the characteristic scale of 11.5 ± 0.5 µm were detected in one fixed orientation of the sample, i.e. with the growth plane of BC parallel to the plane formed by the neutron beam and the spin-echo length. The uniaxial anisotropy revealed agrees with a recently proposed model, which attributes this behavior to the existence of tunnel-like oriented structures inside BC. The evidence of such type of mesostructure anisotropy of BC and BC-PAAM hydrogels was obtained by using the cryo-SEM method.

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The use of reduced graphene oxide (r-GO) is a promising way of fabricating organic–inorganic composites with unique electrical and magnetic properties. In our work, polystyrene/r-GO composites were synthesized, in which both the components are linked together by covalent bonds. The r-GO used differs from the graphene obtained from graphite through mechanical exfoliation using the ‘scotch tape’ by presenting many structural defects. Binding in the composite structure between the components was confirmed by infrared spectroscopy. Elemental analysis was carried out by energy dispersive X-ray analysis. Scanning electron microscopy, X-ray diffraction, and Raman spectroscopy were used to monitor the 2D-order in exfoliated r-GO galleries. Using a vibrating-sample magnetometer, we have shown that the composite magnetization loops demonstrate type-II superconductivity up to room temperature due to r-GO flakes. We believe that a strain field in the r-GO flakes covalently binding to a polymeric matrix is responsible for the superconductivity phenomena.

Spherical nanoparticles of ZrO with 2 and 10 mol% EuO up to 20 nm size were prepared by the method of hydrothermal synthesis for luminescent functionalization of the polymer-inorganic nanocomposites based on poly(methyl methacrylate). Surface modification of oxide nanoparticles was carried out by 3-(trimethoxysilyl)propyl methacrylate, dimethoxymethylvinyl silane and 2-hydroxyethyl methacrylate to provide uniform distribution and to prevent agglomeration of nanosized filler in the polymer matrix. Polymer-inorganic composites were synthesized by in situ free radical polymerization in bulk. Structuring of ZrO -EuO nanoparticles in the poly(methyl methacrylate) was studied by very-small-angle neutron scattering. According to the results, the dependence of photoluminescent properties of ZrO -EuO nanoparticles on the content of lanthanide, the symmetry of the crystal field, surface treatment and the polymer matrix were established. A correlation was shown between Stark splitting in luminescence spectra of ZrO -EuO nanoparticles and their phase composition. Using MMT-assay it was shown that composites based on poly(methyl methacrylate) and ZrO -EuO nanoparticles do not have cytotoxic properties, which makes it possible to use them as prosthesis materials with contrasted and luminescent imaging properties.