Band 5, Heft 1

The effect of plasmon resonance of silver island films (SIF) on the interlayer Förster resonance energy transfer (FRET) between xanthene and oxazine dye molecules was studied. It has been shown that the enhancement of FRET can be controlled by changing in the distance between the donor-acceptor system and the SIF. The maximum increase in energy transfer efficiency ( E ET ) by a factor of 2.6 was recorded at a distance of 6 nm from the SIF. The assumption was made that an increase in E ET can be associated with both the direct appearance of a plasmon-enhanced rate constant of energy transfer and an increase in the quantum yield of the energy donor in direct contact with the SIF. The results can serve as a basis for studying of photoinduced processes in hybrid materials such as “organic dye-plasmon nanoparticles”, to increase the photosensitivity of solar cells in the visible region of the spectrum, and for the studying of photobiological processes, as well as to create materials with desired properties, sensors and light energy converters.

Metal oxide ceramic is getting more attention in current times due to their unique pore structures, hydrophilic surfaces, high chemical, thermal and mechanical stabilities which offer avenues for application in water treatment. This paper presents the results of an experimental study on the effects of different ratios of clay, grog, sawdust and bone char on efficiency of ceramic composite water filters. Filter of different designs were developed from clay (50, 60, 70, 75 and 80) | % | , sawdust (15, 25, and 35) | % | , grog (5 and 15) | % | bone char and 5 | % | ratios by volume and sintered at temperature of 900°C for 6 hours. The Phase and functional group identification of sintered filter investigated with x-ray diffraction and infrared spectroscopy revealed the presence of mixed phase and hydroxyl functional group on the surface of sintered filter. Field emission scanning electron microscopy (FESEM) revealed the porous nature of the microstructures of the sintered filter elements. The superior ceramic water filter design (C900-50-15-35) with total porosity 35.89±0.04 | % | , flow rate 2.05±0.41 | % | and the percent E coli, nitrite and fluoride removal efficiency: 99.6±0.40 | % | , 81.17±0.22 | % | and 96.4±0.42 | % | were obtained from this work. Porosity evaluated by BET study for C900-50-15-35 demonstrated an average pore size and surface area of 5 | nm | and 7.30 | m 2 /g | , respectively.

In the present work we theoretically investigated the excitation of surface plasmon-polaritons (SPPs) in deformed graphene by attenuated total reflection method. We considered the Otto geometry for SPPs excitation in graphene. Efficiency of SPPs excitation strongly depends on the SPPs propagation direction. The frequency and the incident angle of the most effective excitation of SPPs strongly depend on the polarization of the incident light. Our results may open up the new possibilities for strain-induced molding flow of light at nanoscales.

In the context of space-based optics, contamination due to particle deposition on the optics is inevitable and constitutes a critical issue. This gets more challenging for the sensitive heterodyne measurements of the Laser Interferometer Space Antenna (LISA), the space-based gravitational wave observatory to be launched in 2034. Therefore, table-top experiments need to be developed for a better understanding of how micrometer to millimeter sized dust particles, present on optical surfaces, affect LISA measurements. In this work, we present an experimental setup for the simultaneous measurement of the coherent backscattering and the monitoring of particles deposition on the optics to be tested. The results of the first measurements are presented and discussed in this article.

We present a study of the photoinduced birefringence in nanocomposite films of the azopolymer PAZO (poly[1-[4-(3-carboxy-4-hydroxyphenylazo)benzenesulfon amido]-1,2-ethanediyl, sodium salt]) doped with TiO 2 nanoparticles (NP) with different concentrations before and after thermal annealing. The NP represent nanopowder with primary particle size 21 nm. The concentration of the NP was varied from 0% (non-doped azopolymer film) to 5 wt%. The thermal process, applied to the nanocomposite films, includes 1 h heating at 200°C. Previous studies of PAZO show that the polymer is stable up to 270°C. We study the dependence of the maximal birefringence induced with He-Cd laser (λ= 442 nm) on the concentration of the TiO 2 NP in the azopolymer thin films as well as thermal effect on the absorbance spectra of the thin films. As indicated by our results, the birefringence is higher for the thermally annealed samples. An increase of the photoinduced birefringence is also observed for the nanocomposite layers with 1% NP for the non-annealed films, and with 2% NP for the annealed films.