Modification of the MgO–Al2O3–TiO2–SiO2 Glass by Silver Diffusion for the Formation of Luminescent Molecular Clusters

Doklady Chemistry - The capabilities of diffusion treatment of alkali-free MgO–Al2O3–TiO2–SiO2 glass using Ag-containing salt melts or special pastes for the formation of...     

Double stabilization of silver molecular clusters in thin films

The evolution of spectral and luminescent properties of Ag-containing composite coatings prepared by liquid technique has been studied. Double stabilization allows forming thin oxide films containing luminescent small Ag_n (n?<?5) molecular clusters using the liquid technique. These clusters are non-stable intermediate products during the formation of Ag nanoparticles from the ions and neutral atoms. It was found that small luminescent Ag_n molecular clusters (n?<?5) formed in the solutions at the presence of polyvinylpyrrolidone (PVP) remain in PVP/metal nitrates composite coatings and in the calcined metal oxide coatings. Spatial separation of small Ag molecular clusters in the coatings by the oxide nanoparticles of ZnO and MgO prohibits silver clusters growth and non-luminescent silver nanoparticles formation and allows saving coatings’ luminescence properties during thermal treatment.

     

Transparent ZnO–SnO2 Photocatalytic Nanocoatings Prepared by the Polymer–Salt Method

Optics and Spectroscopy - The structure and properties of transparent ZnO–SnO2 photocatalytic coatings formed on glass surfaces by the polymer–salt method are studied. The physical and...     

Photodestruction of Polyvinylpyrrolidone in Aqueous Solutions of Metal Nitrates

Optics and Spectroscopy - Photodecomposition of polyvinylpyrrolidone in solutions of metal nitrates is studied. This polymer oxidates in metal nitrate solutions under UV irradiation by reacting...     

Nonlinear optical limiters of pulsed laser radiation based on carbon‐containing nanostructures in viscous and solid matrices

Results of the study of optical limiters of pulsed laser radiation based on nonlinear effects in carbon nanostructures placed into viscous and solid matrices are presented. A nonlinear optical limiting was studied by nanomaterials based on multi‐wall polyhedral carbon nanostructures (astralens) placed in a sol–gel matrix. Similar studies for single‐wall and multi‐wall carbon‐containing nanotubes placed in polymer matrices with various viscosities were performed. No additional mechanism of optical limiting due to electron structure of single‐wall carbon‐containing nanotubes at their introduction into viscous and solid composite media was found. An influence of polymer matrix composition containing carbon nanotubes (CNTs) on a threshold and ratio of attenuation of laser radiation was demonstrated. The best limiting characteristics were observed at placing CNT into polymethylsiloxane matrix. An effect of “self‐healing” of a medium after laser radiation passage through high viscous liquids was obtained. The high parameters of nonlinear optical limiting (the threshold of limiting 10^?5 J, ratio of attenuation 10³) achieved for the composite material CNT (HiPCO High‐Pressure Carbon Monoxide) and carbon nanofibers in high viscous and solid polymethylsiloxane media allow the design of protective filters for laser radiation operating in wide spectral range. Copyright © 2014 John Wiley & Sons, Ltd.     

Singlet Oxygen Generation in Microcapillary Optical Elements with Photoactive Coatings

Optics and Spectroscopy - The spectral-luminescent properties of oxide nanocoatings containing ZnO and Ag nanoparticles and the processes of singlet-oxygen generation in these coatings are studied....     

Role of the interaction between forming nanocrystals and glass surface on the structure and properties of ZnO-based films

The interaction between glass surface and forming nanocrystals plays the important role in the formation of thin ZnO coatings crystal structure. The comparative study of the crystal structure of thin ZnO-based films and powders having similar chemical compositions was performed with the use of SEM, XRD analysis, optical, and luminescent spectroscopy. The influence of different coatings parameters (chemical composition, thickness) on the spectroscopic and morphological properties of thin films and powders reveals the structural features of the interaction between forming ZnO nanocrystals and glass surface. ZnO–SnO₂ coatings and powders were prepared by liquid polymer-salt technique. This method provides the close contact between the coatings’ precursors with a surface of the glass during both the nucleation and the initial growth stage of forming oxide crystals. The interaction of nanocrystals and substrate surface is responsible for the texture formation in the ZnO films and determines some features of their optical properties.     

Polymer–Salt Synthesis of Yb:YAG Nanopowders and Study of Their Structure and Luminescent Properties

Optics and Spectroscopy - Nanopowders of ytterbium-doped yttrium aluminum garnet are synthesized by the polymer–salt method and their crystal structure and spectral-luminescent properties are...     

The Influence of Polyvinylpyrrolidone on the Structure and Optical Properties of ZnO–MgO Nanocomposites Synthesized by the Polymer–Salt Method

Optics and Spectroscopy - The influence of polyvinylpyrrolidone on the structure and optical properties of ZnO–MgO nanocomposites synthesized by the polymer–salt method is studied. The...     

Study of Fiber Optic Elements Based on a Photoactive Polymer Composition for Sensor Applications

Optics and Spectroscopy - The model of a fiber optic sensor device which operational principle is based on the thermal quenching of luminescence for ambient temperature measurements was...