INFRARED PHOTOLUMINESCENCE SPECTRA OF PBS NANOPARTICLES PREPARED BY LANGMUIR–BLODGETT AND LASER ABLATION METHODS

We optimized the optical setup originally designed for the photoluminescence measurements in the spectral range 400‒1100 nm. New design extends the spectral range into the near infrared region 900‒1700 nm and allows the colloidal solutions measurements in cuvettes as well as the measurements of nanoparticles deposited in the form of thin films on glass substrates. The infrared photoluminescence spectra of the PbS nanoparticles prepared by the Langmuir–Blodgett technique show the higher photoluminescence intensity and the shift to the shorter wavelengths compared to the infrared photoluminescence spectra of the PbS nanoparticles prepared by the laser ablation from PbS target. We aslo proved the high stability of PbS nanoparticles prepared in the form of thin layers

Characterization and Properties of Titanium-Vanadium Oxide Thin Films Prepared by ArF Laser Ablation

Thin films od vanadium-titanium complex oxides were prepared by ArF excimer laser ablation of Tio2 and VO2 targets. The light grey films with thickness of 155 nm were grown on glass and Au substrates and characterized by microscopy, spectroscopy and diffraction techniques. The as-prepared films were nanocrystalline and heating at 450°C in vacuum led to formation of mixture of crystalline V0.95Ti0.05O and TiO nanoparticles. The film shown reversible thermochronic behaviour between 3.0 and 1.4 micrometers. The films, annealed in air oxidize and the colour of the film changes to light yellow. Electrical and optical properties of the films are demonstrated

Excimer Laser-Induced CVD of Carbon Encapsulated Cobalt Nanoparticles

Decomposition of acetylene / Co(CO)(3)(NO)mixtures induced by excimer ArF laser pulses is an efficient technique for preparation of amorphous cobalt nanoparticles encapsulated in carbon. Vacuum heating up to 900 degrees C leads to crystallization the metal core. The cobalt core crystallizes in a face-centered cubic (beta) form as revealed by X-ray and electron diffraction techniques and carbon affords graphite outer part. Properties of the Co(core) - carbon(shell)nanocomposites were examined by spectroscopy and microscopy techniques. Magnetization studies revealed paramagnetic behavior of the as-prepared amorphous deposit and superparamagnetic behavior of the annealed samples

Cobalt oxides supported over ceria-zirconia coated cordierite monoliths as catalysts for deep oxidation of ethanol and N2O decomposition

Cordierite monoliths coated with ceria-zirconia supporting cobalt oxide were prepared, examined in the deep oxidation of ethanol and N2O decomposition, and compared with pelletized commercial cobalt oxide catalyst. Interaction of Co3O4 with ceria-zirconia washcoat led to formation of Co3O4 particles with slightly worse structure ordering resulting in better reducibility than that observed for the commercial Co3O4 catalyst. In oxidation of ethanol, activity of the Co3O4-containing monoliths was comparable with that of pelletized cobalt oxide catalyst with nearly seven times higher content of active components. However, conversions of N2O over the monolith catalysts were lower. Nevertheless, incorporation of Co3O4 onto ZrO2-CeO2 washcoat increased rate of both catalytic reactions, i.e., N2O decomposition and deep ethanol oxidation.Web of Science14761391137

Methodology of removing dust particles from the surface of paper, collagen materials and textiles using the TEA CO2 laser

Cílem této metodiky bylo vytvořit soubor postupů a doporučení pro čištění knihovních materiálů, s jejichž využitím bude možné odstranit prachové částice z jejich povrchu pomocí infračerveného TEA CO2 laseru. Základním požadavkem je efektivní odstranění povrchového znečištění bez poškození ošetřovaného materiálu. Výsledkem je účinná a bezpečná alternativa ke stávajícím metodám čištění