Stimulus-responsive room-temperature phosphorescence(RTP)materials have gained significant attention for their important optoelectronic application prospects.However,the fabrication strategy and underlying mechanism o...Stimulus-responsive room-temperature phosphorescence(RTP)materials have gained significant attention for their important optoelectronic application prospects.However,the fabrication strategy and underlying mechanism of stimulus-responsive RTP materials remain less explored.Herein,we present a reliable strategy for achieving pH-responsive RTP materials by integrating poly(vinyl alcohol)(PVA)with carboxylic acid or amino group functionalized terpyridine(Tpy)derivatives.The resulting Tpy derivativesbased RTP materials displayed reversible changes in emission color,intensity,and lifetime of both prompt and delayed emission.Notably,the RTP emission undergoes a significant diminish upon exposure to acid due to the protonation of Tpy units.Taking advantage of the decent RTP emission and pH-responsiveness of these RTP films,a spatial-time-resolved anti-counterfeiting application is demonstrated as a proof-ofconcept for largely enhancing the security level.This study not only provides new prospects for developing smart RTP materials but also promotes the advancement of optical anti-counterfeiting applications.展开更多
Hydrogen bonding has been employed to suppressnonradiative decay in organic compounds that showroom-temperature phosphorescence (RTP);however, the small number of structurally diverse examplesmakes it unclear how gene...Hydrogen bonding has been employed to suppressnonradiative decay in organic compounds that showroom-temperature phosphorescence (RTP);however, the small number of structurally diverse examplesmakes it unclear how general this strategy is to turnon RTP. In this study, we report highly efficient blueRTP from 4,4′,4′′-nitrilotribenzoic acid (TPA-CO_(2)H)in five structurally and chemically distinct hydrogenbonded supramolecular networks. In doped films inpoly(vinyl alcohol) (PVA), the phosphorescencequantum yield and lifetime (ΦPh and τPh) reach 52%and 275 ms. Boric acid can also be used to turn onRTP, and the performance changes significantlywhen the sample is heated beyond the dehydrationtemperature of this host where there is a 14-foldenhancement in the ΦPh after heat treatment. BlueRTP similar to that observed in PVA was also observed using granulated sugar, gelatine, and paper ashost matrices. This work elucidates for the first timethe role and the generality of hydrogen bonding inactivating efficient blue RTP and examines how thechoice of hydrogen bonding host influences RTPperformance. We further demonstrate how the emission color can be tuned by codoping the films withRhodamine 6G.展开更多
Solid-liquid state bonding of Si3N4 ceramics with TiN-modified Ag-Cu-Ti brazing alloy was used'- to enhance joint strength. The effects of the TiN particles on the microstructures, interfacial reactions, and roo...Solid-liquid state bonding of Si3N4 ceramics with TiN-modified Ag-Cu-Ti brazing alloy was used'- to enhance joint strength. The effects of the TiN particles on the microstructures, interfacial reactions, and room-temperature properties of the joints were investigated. The results show that the TiN particles are gen- erally well dispersed in the Ag-Cu eutectic base and the interface between them is both clean and com-pact. Changes in the TiN volume fractions from 0 to 20% exert no noticeable effect on the interfacial reac-tion between Ag-Cu-Ti and the substrates. Other bonding parameters being constant, the TiN volume frac-tion in the filler material plays a key role in the joint properties. For TiN volume fractions below 20%, the joints are reinforced, especially joints with 5% and 20% TiN. The average shearing strength of joints with 5% TiN is 200.8 MPa, 30% higher than that of joints with no TiN (154.1 MPa). However, for TiN volumes frac- tions above 20%, the joint strengths decrease.展开更多
基金financially supported by the National Natural Science Foundation of China(No.22205249)Zhejiang Provincial Natural Science Foundation of China(No.LQ23B040002)+2 种基金the Sino-German Mobility Program(No.M-0424)Ningbo International Cooperation Project(No.2023H019)China Postdoctoral Science Foundation(Nos.2021TQ0341,2022M723252)。
文摘Stimulus-responsive room-temperature phosphorescence(RTP)materials have gained significant attention for their important optoelectronic application prospects.However,the fabrication strategy and underlying mechanism of stimulus-responsive RTP materials remain less explored.Herein,we present a reliable strategy for achieving pH-responsive RTP materials by integrating poly(vinyl alcohol)(PVA)with carboxylic acid or amino group functionalized terpyridine(Tpy)derivatives.The resulting Tpy derivativesbased RTP materials displayed reversible changes in emission color,intensity,and lifetime of both prompt and delayed emission.Notably,the RTP emission undergoes a significant diminish upon exposure to acid due to the protonation of Tpy units.Taking advantage of the decent RTP emission and pH-responsiveness of these RTP films,a spatial-time-resolved anti-counterfeiting application is demonstrated as a proof-ofconcept for largely enhancing the security level.This study not only provides new prospects for developing smart RTP materials but also promotes the advancement of optical anti-counterfeiting applications.
基金S.W.thanks the China Scholarship Council(grant no.201906250199)for supportfunding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No.897098(AIERTP-PLED)+1 种基金support from the Marie Skłodowska-Curie Individual FellowshipWe also thank the United Kingdom’s Engineering and Physical Sciences Research Council for support(grant no.EP/W007517/1).
文摘Hydrogen bonding has been employed to suppressnonradiative decay in organic compounds that showroom-temperature phosphorescence (RTP);however, the small number of structurally diverse examplesmakes it unclear how general this strategy is to turnon RTP. In this study, we report highly efficient blueRTP from 4,4′,4′′-nitrilotribenzoic acid (TPA-CO_(2)H)in five structurally and chemically distinct hydrogenbonded supramolecular networks. In doped films inpoly(vinyl alcohol) (PVA), the phosphorescencequantum yield and lifetime (ΦPh and τPh) reach 52%and 275 ms. Boric acid can also be used to turn onRTP, and the performance changes significantlywhen the sample is heated beyond the dehydrationtemperature of this host where there is a 14-foldenhancement in the ΦPh after heat treatment. BlueRTP similar to that observed in PVA was also observed using granulated sugar, gelatine, and paper ashost matrices. This work elucidates for the first timethe role and the generality of hydrogen bonding inactivating efficient blue RTP and examines how thechoice of hydrogen bonding host influences RTPperformance. We further demonstrate how the emission color can be tuned by codoping the films withRhodamine 6G.
基金Supported by the National Natural Science Foundation of China (No. 50075046)
文摘Solid-liquid state bonding of Si3N4 ceramics with TiN-modified Ag-Cu-Ti brazing alloy was used'- to enhance joint strength. The effects of the TiN particles on the microstructures, interfacial reactions, and room-temperature properties of the joints were investigated. The results show that the TiN particles are gen- erally well dispersed in the Ag-Cu eutectic base and the interface between them is both clean and com-pact. Changes in the TiN volume fractions from 0 to 20% exert no noticeable effect on the interfacial reac-tion between Ag-Cu-Ti and the substrates. Other bonding parameters being constant, the TiN volume frac-tion in the filler material plays a key role in the joint properties. For TiN volume fractions below 20%, the joints are reinforced, especially joints with 5% and 20% TiN. The average shearing strength of joints with 5% TiN is 200.8 MPa, 30% higher than that of joints with no TiN (154.1 MPa). However, for TiN volumes frac- tions above 20%, the joint strengths decrease.
