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A novel nanocomposite was obtained through the covalent immobilization of lipoic acid on the surface of silver nanoparticles-decorated silica nanoparticles (SiO 2 @Ag). The hybrid organic – inorganic material obtained was characterized by Fourier transform infrared spectroscopy, thermal analysis, scanning and transmision electron microscopy, X-ray photoelectron spectroscopy and UV-Visible spectroscopy. Its antioxidant, cytotoxic, antimicrobial activity and influence on mammalian cells cycle were evaluated. The results of this study have shown that the functionalization of SiO 2 @Ag with lipoic acid resulted in a composite with increased specificity of interaction with different mammalian cell lines and antioxidant activity, but with decreased cytotoxicity and antimicrobial properties. Therefore, the SiO 2 @Ag functionalized with lipoic acid could be successfully used in certain concentrations to modulate the cell cycle, in order to obtain the desired anti-proliferative or stimulatory therapeutic effect.

A novel nanocomposite was obtained through the covalent immobilization of lipoic acid on the surface of silver nanoparticles-decorated silica nanoparticles (SiO

Preparation of ZnO in different nano-morphological forms became a hot topic during the last few years. This tendency was motivated by the wide field of potential applications ranging from optics to electronics and spintronics. In the present work, we deal with the preparation of ZnO nanowires and nanostructured thin films using electrochemical deposition. ZnO nanowires were grown using the template approach, namely by replicating the nanopores of polycarbonate ion track membranes. The method yields uniform arrays of nanowires with the morphology controlled by the shape and size of the templates pores. Adding polyvinylpyrolidone as an additive in the growth bath became a necessity due to the fact that polycarbonate ion track membranes are usually hydrophobic and thus filling of the nanopores with the growth electrolyte is rather difficult. In order to better understand the influence of the additive on the electrochemical deposition of such nanostructures, similar experiments were performed for the deposition of ZnO thin films. Scanning electron microscopy, X-ray diffraction and optical spectroscopy measurements were performed for characterization of the deposited structures.

EPR and TEM investigations on sublimated solid Alq3, [tris(8- hydroxyquinoline)aluminum(III)] are reported. Different paramagnetic centers in microcrystalline Alq3 fractions as synthesized and annealed are observed. Their nature, thermal treatment dependence, as well as correlation with the crystal structure are analyzed. The existence of randomly oriented triplets and quartets in annealed Alq3 fractions is evidenced from the temperature dependence of X- and Q-band EPR spectra. The spin Hamiltonian parameters are given and proposals for the model structures are made.

Amorphous C/Ni superlattice films designed as normal-incidence reflector for 5 nm have been grown on float-glass substrates by magnetron sputter deposition in Ar discharge. A comprehensive set of characterization techniques has been applied: grazing X-ray reflection (0.154 nm), atomic force microscopy and transmission electron microscopy in order to determine the quality of the structure. By comparing the results, it could be concluded that RF-magnetron sputtering technique is a good choice for growing such layered synthetic microstructures.

Transparent and conductive thin layers of TiN have been grown on Corning glass and silicon substrates by the reactive pulsed laser deposition method. An excimer laser (KrF, λ=248 nm, 4.0 J/cm2) was used to ablate a massive, metallic Ti target in a N2 atmosphere. Under optimised conditions, continuous polycrystalline films of fcc TiN exhibiting a lattice parameter a=0.4242 nm very close to the bulk value, an optical transmittance higher than 70% in the 350–1100 nm range, a flat morphology and an electrical conductivity around 550 μΩ cm have been deposited at a substrate temperature of only 400°C. The grown films also posses a good chemical and wear resistance as their properties have not changed after exposure to the ambient atmosphere for 6 months.

In order to make X-ray-UV interference mirrors, we tried to obtain a periodic multilayer structure with thin films of two materials, a high absorption material (Ni) and a low absorption material (C) on a quartz substrate. We present theoretical approaches to determine the optimum values of the thicknesses of each thin film and the number of periods required for maximum reflectivity at normal incidence of a soft X-ray mirror working at (lambda) equals 50 angstroms. We also describe the experimental procedures used for obtaining the multilayer structure and the microscopically investigations.