Preparation Of Luminescent Nanofibers Doped With Transition Metal (Ruthenium(â…¡),Rhenium(â… ) Organic Complexes By Electrospinning

In recent years, electrospinning technique has attracted increasing attention because it is a simple and low-cost method for producing continuous ultrafine polymer fibers with diameters ranging from tens of nanometers to several micrometers. These fibers with high specific surface area and porous structure lead themselves to a wide range of applications including filtration devices, membranes, protective clothing, molecular templates and sensors. So far, many electrospun polymer nanofibers have been reported, and their potential applications have been demonstrated in the fabrication of nanoscale electrical or photoelectronic devices, such as sensors, porous electrode, electromagnetic interference shielding, corrosion protection, light-emitting diodes (LED), solar cells, liquid crystal device and so on. Transition metal organic complexes are among the most widely studied due to their variety of attractive functions based on luminescent properties with a high luminescent efficiency, and relatively high chemical, thermal and photochemical stability. Herein, we report the preparation and luminescent properties of composite nanofibers doped with transition metal organic complexes using electrospinning method. We expect that it can provide several data for nanoscale photoelectronic devices.Luminescent composite nanofibers doped with [Ru(Bphen)2dppz]Cl2 and [Re(CO)3Bphen]Br were fabricated by electrospinning technique, using polyvinyl alcohol(PVA) and poly(vinylpyrrolidone)(PVP) as precursor, respectively. The products were characterized by scanning electron microscope(SEM), UV-vis and fluorescence spectrophotometers, fluorescence lifetimes spectrophotometer. The morphology of composite fibers was discussed by adjusting conditions such as the volatility of the solvent and the concentration of polymer. The results show that one-dimensional composite nanofibers with smooth surface, homogeneous diameters of 500-900 nm and uniform morphology were obtained, when PVP was dissolved in ethanol/dichloromethane mixed solvents with the weight ratio of 50/50 to prepare a 25 wt.% solution. The diameter of fibers increased with increasing the volatile solvent and the polymer concentration.In order to optimize luminescent properties, different amounts of transition metal organic complexes were doped into the composite nanofibers. The photoluminescent character of transition metal organic complexes still remain very well in the composite fibers, and the best doping concentration of ruthenium(II) complex was 0.2 wt.%. The lifetime of Re-Bphen complex increased and the photoluminescence stability was better in composite fibers. This method offered a way for fabricating one-dimensional transition metal complexes-doped composite nanomaterial.