Precisely optimizing the morphology of functional hybrid polymeric systems is crucial to improve its photophysical property and further extend their optoelectronic applications. The physic-chemical property of polymer...Precisely optimizing the morphology of functional hybrid polymeric systems is crucial to improve its photophysical property and further extend their optoelectronic applications. The physic-chemical property of polymeric matrix in electrospinning (ES) processing is a key factor to dominate the condensed structure of these hybrid microstructures and further improve its functionality. Herein, we set a flexible poly(ethylene oxide) (PEO) as the matrix to obtain a series of polydiarylfluorenes (including PHDPF, PODPF and PNDPF) electrospun hybrid microfibers with a robust deep-blue emission. Significantly different from the rough morphology of their poly(N-vinylcarbazole) (PVK) ES hybrid fibers, polydiarylfluorenes/PEO ES fibers showed a smooth morphology and small size with a diameter of 1∼2 µm. Besides, there is a relatively weak phase separation under rapid solvent evaporation during the ES processing, associated with the hydrogen-bonded-assisted network of PEO in ES fibers. These relative “homogeneous” ES fibers present efficient deep-blue emission (PLQY>50%), due to weak interchain aggregation. More interestingly, low fraction of planar (β) conformation appears in the uniform PODPF/PEO ES fibers, induced by the external traction force in ES processing. Meanwhile, PNDPF/PEO ES fibers present a highest sensitivity than those of other ES fibers, associated with the smallest diameter and large surface area. Finally, compared to PODPF/PVK fibers and PODPF/PEO amorphous ES fibers, PODPF/PEO ES fibers obtained from DCE solution exhibit an excellent quenching behavior toward a saturated DNT vapor, mainly due to the synergistic effect of small size, weak separation, β-conformation formation and high deep-blue emission efficiency.展开更多
Molecular-level encapsulation of conjugated polymers serves as a potent approach to isolate the conjugated backbone for reducing intermolecular interactions and manipulating optoelectronic properties in solid state.He...Molecular-level encapsulation of conjugated polymers serves as a potent approach to isolate the conjugated backbone for reducing intermolecular interactions and manipulating optoelectronic properties in solid state.Herein,by tuning the generation of dendritic carbazoles(Cz)in side chains,polydiarylfluorenes with efficient deep-blue emission have been successfully synthesized and explored.The nonplanar twisted Cz dendrons endow their photoluminescence(PL)spectra with enhanced air-aging stability and thermal stability owing to the formation of a self-encapsulation layer.Their impact on solutionstate chain conformation and aggregation was thoroughly studied,combining small-angle neutron scattering(SANS)and dynamic light scattering(DLS).Furthermore,benefiting from the suppressed intermolecular interactions,their films exhibit optimal behavior of singlet excitons in the excited state.Polymer light-emitting diodes(PLEDs)adopting the spin-coated and blade-coated films both present comparable properties and stable electroluminescence(EL)spectra,with Commission Internationale de L'Eclairage(CIE)coordinates(x+y)<0.3,demonstrating the feasibility of a self-encapsulated molecular design strategy.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22075136 and 61874053)the open research fund from Anhui Province Key Laboratory of Environment-friendly Polymer Materials,Anhui Province Key Laboratory of Optoelectronic Materials Science and Technologythe State Key Laboratory of Luminescent Materials and Devices(South China University of Technology).
文摘Precisely optimizing the morphology of functional hybrid polymeric systems is crucial to improve its photophysical property and further extend their optoelectronic applications. The physic-chemical property of polymeric matrix in electrospinning (ES) processing is a key factor to dominate the condensed structure of these hybrid microstructures and further improve its functionality. Herein, we set a flexible poly(ethylene oxide) (PEO) as the matrix to obtain a series of polydiarylfluorenes (including PHDPF, PODPF and PNDPF) electrospun hybrid microfibers with a robust deep-blue emission. Significantly different from the rough morphology of their poly(N-vinylcarbazole) (PVK) ES hybrid fibers, polydiarylfluorenes/PEO ES fibers showed a smooth morphology and small size with a diameter of 1∼2 µm. Besides, there is a relatively weak phase separation under rapid solvent evaporation during the ES processing, associated with the hydrogen-bonded-assisted network of PEO in ES fibers. These relative “homogeneous” ES fibers present efficient deep-blue emission (PLQY>50%), due to weak interchain aggregation. More interestingly, low fraction of planar (β) conformation appears in the uniform PODPF/PEO ES fibers, induced by the external traction force in ES processing. Meanwhile, PNDPF/PEO ES fibers present a highest sensitivity than those of other ES fibers, associated with the smallest diameter and large surface area. Finally, compared to PODPF/PVK fibers and PODPF/PEO amorphous ES fibers, PODPF/PEO ES fibers obtained from DCE solution exhibit an excellent quenching behavior toward a saturated DNT vapor, mainly due to the synergistic effect of small size, weak separation, β-conformation formation and high deep-blue emission efficiency.
基金support from the National Natural Science Foundation of China(No.62205141,62105262,62288102,22075136,62405134)supported by the Natural Science Funds of the Education Committee of Jiangsu Province(No.23KJA430010)+5 种基金the Open Fund of the Key Labora-tory of Advanced Display and System Applications,Min-istry of Education,Shanghai University(OF202505)supported by the Natural Science Foundation of Jiangsu Province for Youth(No.BK20230342)supported by the China Postdoctoral Science Foundation(No.2024M753737)the Shenzhen Science and Tech-nology Program(No.RCBS20231211090610014)support from the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX25-1710)The SANS experiments were performed on the small-angle neutron scattering instrument at the China Spallation Neutron Source(CSNS),Dongguan,China(Project ID:P0123122600014).
文摘Molecular-level encapsulation of conjugated polymers serves as a potent approach to isolate the conjugated backbone for reducing intermolecular interactions and manipulating optoelectronic properties in solid state.Herein,by tuning the generation of dendritic carbazoles(Cz)in side chains,polydiarylfluorenes with efficient deep-blue emission have been successfully synthesized and explored.The nonplanar twisted Cz dendrons endow their photoluminescence(PL)spectra with enhanced air-aging stability and thermal stability owing to the formation of a self-encapsulation layer.Their impact on solutionstate chain conformation and aggregation was thoroughly studied,combining small-angle neutron scattering(SANS)and dynamic light scattering(DLS).Furthermore,benefiting from the suppressed intermolecular interactions,their films exhibit optimal behavior of singlet excitons in the excited state.Polymer light-emitting diodes(PLEDs)adopting the spin-coated and blade-coated films both present comparable properties and stable electroluminescence(EL)spectra,with Commission Internationale de L'Eclairage(CIE)coordinates(x+y)<0.3,demonstrating the feasibility of a self-encapsulated molecular design strategy.
