In the present study, the effect of magnetite (Fe3O4) nanoparticles on the structural and dielectric properties of poly(vinylidene fluoride) (PVDF) matrix was investigated. Distribution of Fe3O4 nanoparticles in the polymer matrix has been studied by scanning electron microscopy (JEOL JSM-7600 F). The structure of the nanocomposite samples was investigated by the X-ray diffraction and Fourier-transform infrared spectroscopy. It was shown that the dielectric permittivity of PVDF + Fe3O4 nanocomposite samples was gradually increased up to 7 wt% of Fe3O4 content. Further increase in the concentration of the filler leads to decrease in the dielectric permittivity. The subsequent decrease in dielectric permittivity at higher Fe3O4 content can be explained by the increase in defects in the structure of the nanocomposite. The comparison of experimental data and the results of theoretical calculations show that the reduction in the empirical value of dielectric permittivity of the nanocomposite is obviously linked with the threshold value of filler. While calculating the theoretical value of the dielectric permittivity for the higher content of the filler, defects in the nanocomposite structure should be considered.

The structure and optic properties of the transparent PP+SiO2 nanocomposites with a relatively high refractive index and enhanced luminescence properties were investigated. X-ray analysis, Fourier-transform infrared (FTIR), Visible-ultraviolet, and photoluminescence spectroscopic methods were used for investigation. The XRD analysis indicated that the fraction of the amorphous phase of the polycrystalline polymer decreases with the introduction of SiO2 nanoparticles. Even though SiO2 nanoparticle is amorphous itself, they play the role of the crystallinity centers in the polymer matrix, and the degree of crystallinity increases in polymer nanocomposites. According to UV-vis spectroscopic analysis that, with the increasing of the concentration of SiO2 nanoparticles distributed in the polymer matrix, the absorption intensity of the samples also increases. It was explained by the hyperchromic effect which is related to raising the optical density of the polymer by introducing the filler particles (SiO2). It was calculated bandgap energy and refractive index on the base of the UV spectra of samples. It has been found that at low concentrations of amorphous silica nanoparticles, the polymer nanocomposite retains its transparency despite having a relatively high refractive index (1.96). Furthermore, the photoluminescence (PL) spectrum of nanocomposites was investigated depending on filler concentration. It was clear that the intensity of the PL spectrums increases with the increase of the filler concentration that is explained by the raising of the luminescence centers in the nanocomposite material. These luminescence centers are oxygen-deficit centers in the spatial structure of the amorphous silica nanoparticles.

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The synthesis of nanoparticles by microorganisms is environmentally safe method. The silver nanoparticles produced by fungi is complex material having different size, shape and other properties depending on the producer. İt is necessary to study new microbial strains to synthesize silver nanoparticles with important properties. The synthesis of different stable silver nanoparticles by the mold fungi was investigated in this work. To achieve this goal different strains (isolates) of Aspergillus niger were used. The most intensive formation of nanoparticles was observed in strains Aspergillus niger BDU-A4, BDU-K8, BDU-UB1 and BDU-UB5.While examining nanoparticles the following analysis methods were used: UV-Visible Spectroscopy, Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy. Electron microscopic examination showed that the shape, size and nature of nanoparticles’ clusters were dependent on fungal strains. The shape of nanoparticles is usually circular but it may be oval like in case of nanoclusters consisting of a few spherical nanoparticles. Their size varies from 20 to 100 nm.The formation of free ellipsoidal shape nanoparticles was observed at strain of Aspergillus niger BDU-K8, that varies in the range 62,9 - 68,4 nm.

In the present study we had an aim to develop the methods of functionalizing the surface of magnetite nanoparticles with cefotaxime and ceftriaxone antibiotics. The quantitative analysis of the nanostructured cephalosporins was determined by Atom Absorbance Spectroscopy (AAS) and based on the Lambert-Beer law. The engineered nanostructures were tested on gram-negative microorganisms Klebsiella spp., of Enterobacteriaceae, and gram-positive bacteria Staphylococcus aureus, each having multi-drug resistance properties.