The lack of macro-continuity and mechanical strength of covalent organic frameworks(COFs)has significantly limited their practical applications.Here,we propose an“alcohol-triggered defect cleavage”strategy to precis...The lack of macro-continuity and mechanical strength of covalent organic frameworks(COFs)has significantly limited their practical applications.Here,we propose an“alcohol-triggered defect cleavage”strategy to precisely regulate the growth and stacking of COF grains through a moderate reversed Schiff base reaction,realizing the direct synthesis of COF nanofibers(CNFs)with high aspect ratio(L/D=103.05)and long length(>20μm).An individual CNF exhibits a biomimetic scale-like architecture,achieving superior flexibility and fatigue resistance under dynamic bending via a multiscale stress dissipation mechanism.Taking advantages of these structural features,we engineer CNF aerogels(CNF-As)with programmable porous structures(e.g.,honeycomb,lamellar,isotropic)via directional ice-template methodology.CNF-As demonstrate 100%COF content,high specific surface area(396.15 m^(2)g^(-1))and superelasticity(~0%elastic deformation after 500 compression cycles at 50%strain),outperforming most COF-based counterparts.Compared with the conventional COF aerogels,the unique structural features of CNF-A enable it to perform outstandingly in uranium extraction,with an 11.72-fold increment in adsorption capacity(920.12 mg g^(-1))and adsorption rate(89.9%),and a 2.48-fold improvement in selectivity(U/V=2.31).This study provides a direct strategy for the development of next-generation COF materials with outstanding functionality and structural robustness.展开更多
Covalent organic frameworks(COFs)are an emerging class of porous crystalline materials formed by the precise assembly of organic molecular building blocks into extended periodic structures via strong covalent bonds.Th...Covalent organic frameworks(COFs)are an emerging class of porous crystalline materials formed by the precise assembly of organic molecular building blocks into extended periodic structures via strong covalent bonds.They feature well-defined pore structure,high specific surface area,and tunable physicochemical properties,endowing them with broad application prospects in gas storage,molecular separation.展开更多
High piezoelectric composite films composed of poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)and ferromagnetic cobalt ferrite(CoFe_(2)O_(4))(0.00 wt%to 0.2 wt%)are prepared by a solution casting method acc...High piezoelectric composite films composed of poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)and ferromagnetic cobalt ferrite(CoFe_(2)O_(4))(0.00 wt%to 0.2 wt%)are prepared by a solution casting method accompanied by uniaxial stretching and high electric field poling.The decisive effect of the poling electric field on the power generating capability was confirmed by the experiments.For pure PVDF-HFP films,when the maximum electric field Emax is 120 MV/m,the calibrated open circuit voltage reaches 2.93 V,which is much higher than those poled at lower electric fields(70 MV/m:1.41 V;90 MV/m:2.11 V).Furthermore,the addition of CoFe_(2)O_(4)also influences the piezoelectricity dramatically.In the samples containing 0.15 wt%CoFe_(2)O_(4),the calibrated open circuit voltage increases to the maximum value of 3.57 V.Meanwhile,the relative fraction of theβ-phase and the crystallinity degree are 99%and 48%,respectively.The effects of CoFe_(2)O_(4)nanoparticles on initial crystallization,uniaxial stretching and high electric field poling are investigated by XRD,FTIR and DSC.展开更多
2025年1月9日,天津大学姜忠义教授团队在Angewandte Chemie International Edition期刊发表题为“Confining Phosphoric Acid in Quaternized COF Channels for Ultra-stable and Fast Anhydrous Proton Transport”的研究论文,团队成...2025年1月9日,天津大学姜忠义教授团队在Angewandte Chemie International Edition期刊发表题为“Confining Phosphoric Acid in Quaternized COF Channels for Ultra-stable and Fast Anhydrous Proton Transport”的研究论文,团队成员逢霄为论文第一作者,姜忠义教授为论文通讯作者.展开更多
Ionic covalent organic framework(COF)lamellar membranes are the alternative materials as promising Li^(+)conductors for all-solid-state lithium batteries.However,COF lamellar membrane suffers from poor structural stab...Ionic covalent organic framework(COF)lamellar membranes are the alternative materials as promising Li^(+)conductors for all-solid-state lithium batteries.However,COF lamellar membrane suffers from poor structural stability and inevitable cross-layer transfer resistance due to the weak interaction at interface of adjacent nanosheets.Herein,a lamellar polymer-threaded ionic COF(PEI@TpPa-SO_(3)Li)composite electrolyte with single Li^(+)conduction was prepared by assembling lithium sulfonated COF(TpPa-SO_(3)Li)nanosheets and then threading them with polyethyleneimine(PEI)chains.It reveals that the threaded PEI chains induce the oriented permutation of pore channel of PEI@TpPa-SO_(3)Li electrolyte through electrostatic interaction between-NH_(2)/-NH-and-SO_(3)Li groups.This enables the construction of continuous and aligned-SO_(3)^(-)...Li^(+)...-NH_(2)/-NH-pairs along pore channels,which act as efficient Li^(+)conducting sites and afford high Li^(+)hopping conduction(1.4×10^(-4)S cm^(-1)at 30℃)with a high Young's modulus of 408.7 MP and wide electrochemical stability window of 0~4.7 V.The assembled LiFePO_(4)‖Li and LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)‖Li half-cells achieve high discharge capacities of 155.0 mAh g^(-1)and 167.2 mAh g^(-1)at 30℃under0.2 C,respectively,with high capacity retention of 98%after 300 cycles.This study provides an alternative route to highly ion-conductive lamellar porous electrolytes for high-performance energy devices.展开更多
基金supported by the National Natural Science Foundation of China(No.52403035)the Shanghai Sailing Program(23YF1400300)+1 种基金the Fundamental Research Funds for the Central Universities(2232023D-05)the Weiqiao Teaching and Research Innovation Program.
文摘The lack of macro-continuity and mechanical strength of covalent organic frameworks(COFs)has significantly limited their practical applications.Here,we propose an“alcohol-triggered defect cleavage”strategy to precisely regulate the growth and stacking of COF grains through a moderate reversed Schiff base reaction,realizing the direct synthesis of COF nanofibers(CNFs)with high aspect ratio(L/D=103.05)and long length(>20μm).An individual CNF exhibits a biomimetic scale-like architecture,achieving superior flexibility and fatigue resistance under dynamic bending via a multiscale stress dissipation mechanism.Taking advantages of these structural features,we engineer CNF aerogels(CNF-As)with programmable porous structures(e.g.,honeycomb,lamellar,isotropic)via directional ice-template methodology.CNF-As demonstrate 100%COF content,high specific surface area(396.15 m^(2)g^(-1))and superelasticity(~0%elastic deformation after 500 compression cycles at 50%strain),outperforming most COF-based counterparts.Compared with the conventional COF aerogels,the unique structural features of CNF-A enable it to perform outstandingly in uranium extraction,with an 11.72-fold increment in adsorption capacity(920.12 mg g^(-1))and adsorption rate(89.9%),and a 2.48-fold improvement in selectivity(U/V=2.31).This study provides a direct strategy for the development of next-generation COF materials with outstanding functionality and structural robustness.
文摘Covalent organic frameworks(COFs)are an emerging class of porous crystalline materials formed by the precise assembly of organic molecular building blocks into extended periodic structures via strong covalent bonds.They feature well-defined pore structure,high specific surface area,and tunable physicochemical properties,endowing them with broad application prospects in gas storage,molecular separation.
基金supported by National Natural Science Foundation of China(No.51703015)Fundamental Research Funds for the Central Universities(No.2020CDJQY-A008).
文摘High piezoelectric composite films composed of poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)and ferromagnetic cobalt ferrite(CoFe_(2)O_(4))(0.00 wt%to 0.2 wt%)are prepared by a solution casting method accompanied by uniaxial stretching and high electric field poling.The decisive effect of the poling electric field on the power generating capability was confirmed by the experiments.For pure PVDF-HFP films,when the maximum electric field Emax is 120 MV/m,the calibrated open circuit voltage reaches 2.93 V,which is much higher than those poled at lower electric fields(70 MV/m:1.41 V;90 MV/m:2.11 V).Furthermore,the addition of CoFe_(2)O_(4)also influences the piezoelectricity dramatically.In the samples containing 0.15 wt%CoFe_(2)O_(4),the calibrated open circuit voltage increases to the maximum value of 3.57 V.Meanwhile,the relative fraction of theβ-phase and the crystallinity degree are 99%and 48%,respectively.The effects of CoFe_(2)O_(4)nanoparticles on initial crystallization,uniaxial stretching and high electric field poling are investigated by XRD,FTIR and DSC.
文摘2025年1月9日,天津大学姜忠义教授团队在Angewandte Chemie International Edition期刊发表题为“Confining Phosphoric Acid in Quaternized COF Channels for Ultra-stable and Fast Anhydrous Proton Transport”的研究论文,团队成员逢霄为论文第一作者,姜忠义教授为论文通讯作者.
基金supported by the financial support from the National Key Research and Development Program(2022YFB3805204,2022YFB3805201)National Natural Science Foundation of China(22478362)+2 种基金Joint Foundation for Science and Technology Research&Development Plan of Henan Province(222301420003 and 232301420038)Key Scientific and Technological Project of Henan Province(242102321032)Foundation of Henan Educational Committee(22A530003)。
文摘Ionic covalent organic framework(COF)lamellar membranes are the alternative materials as promising Li^(+)conductors for all-solid-state lithium batteries.However,COF lamellar membrane suffers from poor structural stability and inevitable cross-layer transfer resistance due to the weak interaction at interface of adjacent nanosheets.Herein,a lamellar polymer-threaded ionic COF(PEI@TpPa-SO_(3)Li)composite electrolyte with single Li^(+)conduction was prepared by assembling lithium sulfonated COF(TpPa-SO_(3)Li)nanosheets and then threading them with polyethyleneimine(PEI)chains.It reveals that the threaded PEI chains induce the oriented permutation of pore channel of PEI@TpPa-SO_(3)Li electrolyte through electrostatic interaction between-NH_(2)/-NH-and-SO_(3)Li groups.This enables the construction of continuous and aligned-SO_(3)^(-)...Li^(+)...-NH_(2)/-NH-pairs along pore channels,which act as efficient Li^(+)conducting sites and afford high Li^(+)hopping conduction(1.4×10^(-4)S cm^(-1)at 30℃)with a high Young's modulus of 408.7 MP and wide electrochemical stability window of 0~4.7 V.The assembled LiFePO_(4)‖Li and LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)‖Li half-cells achieve high discharge capacities of 155.0 mAh g^(-1)and 167.2 mAh g^(-1)at 30℃under0.2 C,respectively,with high capacity retention of 98%after 300 cycles.This study provides an alternative route to highly ion-conductive lamellar porous electrolytes for high-performance energy devices.
