| Recently,the emerging photoluminescent carbon dots(CDs)have.drawn increasing attention and be widely applied in many fields,such as bioimaging,biosensing,drug delivery,photocatalysis and photoelectric devices,due to their fascinating properties such as good water solubility,excellent biocompatibility,chemical intertness,flourescence stability,low toxicity and easy surface functionalization.Nowadays,the research of CDs mianly focuses on looking for more convenient,low-cost and environmentally friendly synthetic methods and widening their applicaitions in various fields.With respect to the applications of CDs,with the exception of biological applications,most envisoned applications are not based on single-particle CDs or their solutions,which will greatly limit the applications of CDs in other revelant fields.Up to now,CDs doped two-dimensional(2D)coatings and three-dimensional(3D)monoliths have been reported successively and be successfully applied to light emitting diode(LED),inkjet printing and so on.However,one-dimensional(ID)CDs doped composite fibers are scarcely reported.Accordingly,in this paper,we synthesized carbon dots(CDs)via one-step hydrothermal method at first,and then prepared 1D CDs doped composite fibers and their corresponding 1D composite fibers incorporated with Ag nanowire(Ag NW)through the combination of sol-gel process and electrospinning technique.The main results of this thesis are as follows:1.we used N-(?-aminoethyl)-y-aminopropylmethylbimethoxy silane(AEAPMS)as surface passivation agent to synthesize the AEAPMS founctionalized CDs(SiCDs)via one-step hydothermal method.The particle sizes of resultant well-dispersed SiCDs are uniform and the average particle size is about 3.72 nm.Moreover,the fluorescence intensity of SiCDs is fairly high,the fluorescence emission properties are independent of excitation wavelengths,the average fluorescence lifetime and absolute quantum yield of SiCDs can reach up to 11.58 ns and 87.32%,respectively,and the SiCDs at high concentration still remain high transmittance in the visible region.2.We choosed methyltriethoxysilane(MTES)as a suitable matrix,and then mixed SiCDs with MTES to prepare the SiCDs/MTES mixed solution.After the hydrolysis,condensation and polycondensation reations of MTES and the copolymerization reaction of MTES and SiCDs,the electrospinning sol was formed,and then the SiCDs/MTES copolymerized composite fibers were prepared through electrospinning process.The diameters of as-prepared fibers are 0.5?2.5 ?m,the average fluorescence lifetime and absolute quantum yield of as-prepared composite fibers can reach up to 10.53 ns and 24.96%,respectively.And as-prepared composite fibers remain high transmittance in the visible region.More importantly,intense fluorescences are seen throughout overall composite fibers under laser scanning confocal microscope(LSCM)and fluorescence lifetime imaging microscope(FLIM),thus indicating as-prepared composite fibers have potential applications in bioimaging and photoelectric devices.Moreover,as-prepared composite fibers are also expected to be applied in heat-resisting materials and super-hydrophobic materials,owing to their excellent thermal stability and hydrophobicity.3.The SiCDs/MTES copolymerized composite fibers incorporated with Ag NW were prepared by adding Ag NW into the SiCDs/MTES mixed solution.The diameters of resultant compsite fibers slightly increase to 700 nm after the incorporation with Ag NW.The average fluorescence lifetime of resultant composite fibers incorporated with Ag NW remains unchaged and they also show high transmittance in the visible region.In addition,resultant composite fibers doped with Ag NW under FLIM show excellent fluorescence properties,thus indicating their great potential applications in the fields of biomedicine and photoelectric devices.However,on account of the incorporation of Ag NW.the absolute quantum yield slightly decreases to 17.84%from 24.96%,and the fluorescence intensity is not enhanced by Ag NW. |
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