Poly Phenyl Acetylene/inorganic Semiconductor Composite Nano Fiber Optical Performance Research

Electrospinning is an effective method of high efficiency and little waste to preparepolymer nanofibers. Electrospinning occurs when the electrical forces at the surface ofa polymer solution or melt from polymers overcome the surface tension and cause anelectrically charged jet to eject. The jet is draught and thinned fleetly with thevolatilization of solvent or solidification of melt under the electric force andelectrostatic repulsive force. Consequently, the nanofiber matters are obtainedultimately on the take-over electrode. At the beginning of this century, scientists beganto prepare various kinds of nanofibers by electrospinning method. Inorganic/organiccomposite nanofibers have been applied widely in fields as diverse as optoelectronics,biological medicine, biochemistry protection, catalysis, efficient filtration, and sensortechnology.In this paper, we investigated the precursory poly （phenylene vinylene）（PPV） withexcellent photoluminescence and electroluminescence properties. Finally, we preparedluminescent PPV/TiO₂and PPV precursor/PVA/CdTe composite nanofibers by theelectrospinning technique. The properties of the composite nanofibers are also studied.（1） The PPV were synthetized by Wessling method. In order to determine theoptimal technological conditions, we investigated the influence of basic conditions ofPPV, such as concentrations, working distance and positive voltage. The fiber diameterof ultrafine PPV/TiO₂nanofibers ranged from100to300nm. The effects of differentTiO₂content on diameter, morphology, structure, optical properties and crystallinity ofcomposite fibers were discussed.（2） The thiol-stabilized fluorescent CdTe nanocrystals were synthetized. We made PPV precursor/PVA/CdTe composite nanofibers directly from single-colored CdTenanocrystals and a PPV precursor using PVA as intermediate. In this system, part of thePPV precursor chain reacted with PVA to form C–O–C linkages, which interrupted theconjugation of PPV polymer chains and decreased the p-conjugated chain length. Theexistence of PVA weakened the interaction between nanocrystals and the PPVprecursor and hence inhibited the deposition of nanocrystal. The CdTe nanocrystalswere well dispersed in the as-prepared composite nanofibers.