Gamma induced changes in Makrofol/CdSe nanocomposite films

In our present work, we applied ex-situ casting procedure to prepare a nanocomposite (NCP) from Makrofol polycarbonate (PC) and CdSe nanoparticles. The CdSe nanoparticles were prepared by thermolysis procedure in the presence of N2 gas flow. Rietveld refinement of x-ray data illustrated that the CdSe accustoms cubic zinc blend structure of a 6.057 Å lattice parameter and 2 nm typical grain size. Samples from the prepared NCP were exposed to γ dosages (20-250 kGy). The modifications induced in the NCP films owing to γ dosages have been studied. The γ irradiation (50-250 kGy) causes the crosslinks that reduces the optical bandgap from 4.15 to 3.81 eV; associated with an increase in dielectric parameters and refractive index. This is attributed to the increase of the mass fraction of the disordered regions as specified by XRD. The PC-CdSe NCP was found to have reaction to color modification which makes it suitable in saleable reproduction on printing press.

Sonochemical Synthesis, Characterization and Optical Properties of Tb-Doped CdSe Nanoparticles: Synergistic Effect between Photocatalysis and Sonocatalysis

In this study, Tb-doped CdSe nanoparticles with variable Tb3+ content were synthesized by a simple sonochemical technique. The synthesized nanoparticles were characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and powder X-ray diffraction (XRD). The sono-photocatalytic activities of the as-prepared specimens were assessed for the degradation of Reactive Black 5. The experimental results show that the sono-photocatalytic process (85.25%) produced a higher degradation percentage than the individual sono- (22%) and photocatalytic degradation (8%) processes for an initial dye concentration and Tb-doped CdSe dosage of 20 mg/L and 1 g/L, respectively. Response surface methodology (RSM) was utilized to assess model and optimize the impacts of the operational parameters, namely, the Tb3+ content, initial dye concentration, catalyst dosage, and time. The addition of benzoquinone results in remarkably inhibited degradation and the addition of ammonium oxalate reduced the removal percentage to 24%. Superoxide radicals and photogenerated holes were detected as the main oxidative species.

Peptoid-directed assembly of CdSe nanoparticles

Pre-assembled peptoid tubes and sheets are used as a generalizable platform to template the assembly of controllable densities of CdSe quantum dots and clusters through a robust, covalent linkage.