In this article, low-threshold random laser with one mirror and feedback is investigated in PMMA film containing Rhodamine 590 and TiO2 nano-particles. Incoherent and coherent laser emission is observed. Optics microscopy and Scanning Probe Microscopy are used to investigate the film structure and the principle of incoherent and coherent laser is analyzed.
Thermally reduced graphene oxide (trGO) was successfully prepared and confirmed by XRD then dispersed in polystyrene (PS) and Acrylonitrile-Butadiene-Styrene (ABS) polymers and evaluated for EMI shielding in microwave and infrared (IR) region. Thickness of prepared polymer/trGO composite films were 200-250 micron. It was observed that trGO has more compatibility with PS then ABS and dispersed more easily and uniformly in PS than ABS. This effect was also observed in IR shielding as ABS+15trGO have 3% transmission and PS+1% trGO have 1.5% transmission. Maximum 29 dB and 25 dB shielding effectiveness was measured by vector network analyzer (VNA) in microwave region (9-18 GHz) of PS+2% trGO and ABS+2% trGo composite respectively. These results clearly indicating that trGO is more compatible with PS than ABS and form more stable and mature interconnected network structure in PS at lower concentrations.
Au/SiO2 nano-composite thin films with 3 to 65 vol% Au content were prepared by induction-coil-coupled plasma sputtering. Au particles dispersed in the SiO2 matrix can be prepared by controlling the deposition time of one Au layer and the thickness of the one SiO2 layer. The Au nano-particle dispersed Au/SiO2 multilayer with an uniform nano-layered microstructure showed the absorption peak at the wavelength of 560 nm. The heat-treated Au/SiO2 films containing 3 to 65 vol% Au showed absorption peaks at the wavelength of 540 to 560 nm, while no absorption peak was observed in the as-deposited multilayers containing more than 12 vol% Au.
Flexible nano-GFO/PVDF piezoelectric-polymer nano-composite films for mechanical energy harvesting