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The impedance and thermal conductivity properties of prepared organic epoxy/polyhedral oligomeric silsequioxane (POSS) nanocomposites were studied. The measurements of the impedance were carried out using the impedance technique as a function of applied field frequency range from 20 kHz to 1 MHz, temperature range from 20°C–110°C, and POSS filler concentrations 5, 10, and 20 wt%. The AC conductivity and dielectric properties were determined from the impedance data. It was found that the AC conductivity and dielectric constant are increased by increasing the POSS content in the nanocomposites. The calculated activation energy varies with the filler content, temperature, and applied frequency. The observed electrical results fit approximately the reported equations concerning the AC conductivity of the prepared nanocomposites. The dielectric behavior was explained on the basis of the interfacial polarization, dipolar polarization, and decrease in the hindrance produced by the polymer matrix. The thermal con...

An epoxy network structure made of diglycidylether of bisphenol-A and diamino diphenylsulfone was modified by adding various amounts of an epoxy functionalized polyhedral oligomeric silsesquioxane. The obtained nanocomposites were characterized in terms of optical and dielectric properties. The UV-absorption spectra were collected in the wavelength range of 400–800 nm. The optical data were analyzed in terms of absorption formula for non-crystalline materials. The optical energy gap and other basic constants, such as energy tails, dielectric constants, refractive index and optical conductivity, were determined and showed a clear dependence on the POSS concentration. It was found that the optical energy gap for the neat epoxy resin is less than for nanocomposites, and it decreases with increase in the POSS content. The refractive index of nanocomposites was determined from the calculated values of absorption and reflectance. It was found that the refractive index and the dielectric constants increased with...

Novel acyclic and cyclic merocyanine dyes derived from the nucleu of furo [(3,2- d) pyrazole; imidazole]were prepared. The electronic visible absorption spectra of all the synthesized new cyanine dyes were examined in 95% ethanol solution to evaluate their photosensitization properties. Antibacterial and antifungal activities for some selected dyes were tested against various bacterial and fungal strains (Escherichia coli, Staphylococcus aureus, Aspergillus flavus and Candida albicans) to evaluate their antimicrobial activity. Structural identification was carried out via elemental analysis, visible spectra, IR and 1H NMR spectroscopic data.

We propose a new approximation scheme to obtain analytic expressions for the Schrodinger equation with isotropic velocity-dependent potential to determine the scattering phase shift. In order to test the validity of our approach, we applied it to an exactly solvable model for nucleon-nucleon scattering. The results of the variation iteration method (VIM) formalism compare quite well with those of the exactly solvable model. The developed formalism can be applied in problems concerning pion-nucleon, nucleon-nucleon, and electron-atom scattering.