With the goal of improving processability of imide oligomers and achieving high toughness of thermosetting polyimides, a series of 4-phenylethynylphthalic anhydride（PEPA）-terminated imide oligomers prepared by the r...With the goal of improving processability of imide oligomers and achieving high toughness of thermosetting polyimides, a series of 4-phenylethynylphthalic anhydride（PEPA）-terminated imide oligomers prepared by the reaction of 2,3,3＇,4＇-diphenyl ether tetracarboxylic acid dianhydride（a-ODPA） and 3,4＇-oxydianiline（3,4＇-ODA） with different molecular weights（degree of polymerization： n = 1？9） were formed. The resultant oligomers with different molecular weights were characterized for their chemical architecture, cure behavior, thermal properties, solubility in organic solvents and rheological characteristics. Besides, the thermal properties and tensile test of cured polyimide films were also evaluated. The imide oligomer（degree of polymerization： n = 1） has some somewhat crystalline phase, and imide oligomers（degree of polymerization： n = 2？9） showed excellent solubility（40 wt%） in N-methyl-2-pyrrolidone（NMP） and N,Ndimethylacetamide（DMAc） at room temperature. Furthermore, the rheological properties of imide oligomers showed very low melt viscosity and wider processing window. The cured films exhibited good thermal properties with the glass transition temperatures of 282？373 ？C and 5 wt% thermal decomposition temperatures higher than 551 ？C in nitrogen atmosphere. The elongation at break of the prepared films was found to be high（almost 〉 9.3%）.展开更多
Polymeric carbon nitride(PCN)has garnered increasing attention as a metal-free photocatalyst with a suitable band gap.In efforts to enhance its photocatalytic performance,researchers have examined various PCN material...Polymeric carbon nitride(PCN)has garnered increasing attention as a metal-free photocatalyst with a suitable band gap.In efforts to enhance its photocatalytic performance,researchers have examined various PCN materials,including poly(heptazine imide)(PHI)and poly(triazine imide)(PTI),two isomers within the PCN family that exhibit distinct and superior photocatalytic activity compared to other forms.The challenge,however,lies in the common practice among researchers to categorize PHI and PTI along with other PCN types under the overarching term“g-C_(3)N_(4),”which significantly impedes optimization efforts.The objective of this review is to provide comprehensive insights into the structural features,photoelectrochemical properties,and effective characterization methods employed for distinguishing between PHI and PTI materials.The review also summarizes various optimization strategies,such as crystallinity adjustments,defect engineering,morphology control,constructing heterojunction,and atomic-level metal loading dispersion,to elevate the photocatalytic activity of PHI and PTI,in addition to summarizing the history of carbon nitride development.Furthermore,this review highlights the primary applications of PHI and PTI,encompassing nitrogen fixation,biomass conversion,organic synthesis,CO_(2)reduction,pollutant degradation,H_(2)O_(2)production,and photocatalytic water splitting.Lastly,the prospects and challenges associated with further advancing PHI and PTI are thoroughly examined.展开更多
Carbon nitride-based photocatalysts hold an enormous potential in producing hydrogen.A strategy to simultaneously create isotype heterojunctions and active sites in highly-crystallized carbon nitride is anticipated to...Carbon nitride-based photocatalysts hold an enormous potential in producing hydrogen.A strategy to simultaneously create isotype heterojunctions and active sites in highly-crystallized carbon nitride is anticipated to significantly boost the photocatalytic activity,but is yet to be realized.Herein,we find that cobalt salt added in the ionothermal synthesis can promote the phase transition of heptazine-based crystalline carbon nitride(CCN)to triazine-based poly(triazine imide)(PTI),rendering the creation of singleatom cobalt coordinated isotype CCN/PTI heterojunction.Co-CCN/PTI exhibits an appreciable apparent quantum yield of 20.88%at 425 nm for photocatalytic hydrogen production with a rate achieving3538μmol h^(-1)g^(-1)(λ>420 nm),which is 4.8 times that of CCN and 27.6 times that of PTI.The high photocatalytic activity is attributed to the Type II isotype highly-crystallized CCN/PTI heterojunction for promoting charge carrier migration,and the single-atom Co sites for accelerating surface oxidation reaction.展开更多
Poly(ether imide)(PEI)has shown satisfactory corrosion protection capability with good adhesion strength as a coating for magnesium(Mg),a potential candidate of biodegradable orthopedic implant material.However,its in...Poly(ether imide)(PEI)has shown satisfactory corrosion protection capability with good adhesion strength as a coating for magnesium(Mg),a potential candidate of biodegradable orthopedic implant material.However,its innate hydrophobic property causes insufficient osteoblast affinity and a lack of osseointegration.Herein,we modify the physical and chemical properties of a PEI-coated Mg implant.A plasma immersion ion implantation technique is combined with direct current(DC)magnetron sputtering to introduce biologically compatible tantalum(Ta)onto the surface of the PEI coating.The PEI-coating layer is not damaged during this process owing to the extremely short processing time(30 s),retaining its high corrosion protection property and adhesion stability.The Ta-implanted layer(roughly 10-nm-thick)on the topmost PEI surface generates long-term surface hydrophilicity and favorable surface conditions for pre-osteoblasts to adhere,proliferate,and differentiate.Furthermore,in a rabbit femur study,the Ta/PEI-coated Mg implant demonstrates significantly enhanced bone tissue affinity and osseointegration capability.These results indicate that Ta/PEI-coated Mg is promising for achieving early mechanical fixation and long-term success in biodegradable orthopedic implant applications.展开更多
It is of great significance to design and synthesize highly efficient n-type organic small molecules as electron-transporting layer(ETL) materials to achieve high performance planar perovskite solar cells(PVKSCs) with...It is of great significance to design and synthesize highly efficient n-type organic small molecules as electron-transporting layer(ETL) materials to achieve high performance planar perovskite solar cells(PVKSCs) with lowtemperature solution-processing. In this article, acenaphthylene-imide based small molecules AI1, AI2 and AI3 were developed with lower-lying LUMO energy levels and were further applied as non-fullerene ETL materials for solutionprocessed PVKSCs. When TiO2/AIX bilayer was used as ETL,an average power conversion efficiency(PCE) of 15.0% was achieved for TiO2/AI1 based PVKSCs with conventional configuration, while pristine TiO2 based devices presented a PCE of 11.7% only. All the results demonstrate that acenaphthylene-imide derivatives could be promising ETL materials to accomplish low-temperature solution-processed high performance PVKSCs.展开更多
Poly(heptazine imide)(PHI),a semicrystalline version of carbon nitride photocatalyst based on heptazine units,has gained significant attention for solar H_(2)production benefiting from its advantages including molecul...Poly(heptazine imide)(PHI),a semicrystalline version of carbon nitride photocatalyst based on heptazine units,has gained significant attention for solar H_(2)production benefiting from its advantages including molecular synthetic versatility,excellent physicochemical stability and suitable energy band structure to capture visible photons.Typically,PHI is obtained in saltmelt synthesis in the presence of alkali metal chlorides.Herein,we examined the role of binary alkali metal bromides(LiBr/NaBr)with diverse compositions and melting points to rationally modulate the polymerization process,structure,and properties of PHI.Solid characterizations revealed that semicrystalline PHI with a condensedπ-conjugated system and rapid charge separation rates were obtained in the presence of LiBr/NaBr.Accordingly,the apparent quantum yield of hydrogen using the optimized PHI reaches up to 62.3%at 420 nm.The density functional theory calculation shows that the dehydrogenation of the ethylene glycol has a lower energy barrier than the dehydrogenation of the other alcohols from the thermodynamic point of view.This study holds great promise for rational modulation of the structure and properties of conjugated polymeric materials.展开更多
A novel poly(ether imide)s containing phthalazinone and isopropyl moieties derived from 2-(4-aminophenyl)-4-[4-(4-aminophenoxy)phenyl]-phthalazin-1-one and bisphenol-A diphthalic anhydride was synthesized by one-step ...A novel poly(ether imide)s containing phthalazinone and isopropyl moieties derived from 2-(4-aminophenyl)-4-[4-(4-aminophenoxy)phenyl]-phthalazin-1-one and bisphenol-A diphthalic anhydride was synthesized by one-step solution condensation polymerization in nr-cresol. The polymer was characterized by FTIR, NMR, molecular weights, glass transition temperature, thermal degradation temperature and WAXD.展开更多
A series of novel aromatic poly ( amide imide)s containing phthalazinone moieties were prepared from 2-(4-aminophenyl)-4-[3-methyl-4-(4-aminophenoxy)-2,3-phthalazinone-1], a novel diamine 1 with four diimide-dicarboxy...A series of novel aromatic poly ( amide imide)s containing phthalazinone moieties were prepared from 2-(4-aminophenyl)-4-[3-methyl-4-(4-aminophenoxy)-2,3-phthalazinone-1], a novel diamine 1 with four diimide-dicarboxylic acids by Yamazaki phosphorylation method with the inherent viscosity of 0.36~0.65 dL/g. These polymers had high glass transition temperatures above 300C and they lost 10% weight between 426~475C in N2. The structure of diamine 1 and the polymers was confirmed by IR, 1H NMR and MS. The obtained polymers were readily soluble in polar solvents such as NMP, m-cresol etc. and easily cast into tough, flexible films. The X-ray indicated that they are all amorphous.展开更多
基金financially supported by the National 863 Project of China(No.2012AA03A212)the National Natural Science Foundation of China(No.51203019)
文摘With the goal of improving processability of imide oligomers and achieving high toughness of thermosetting polyimides, a series of 4-phenylethynylphthalic anhydride（PEPA）-terminated imide oligomers prepared by the reaction of 2,3,3＇,4＇-diphenyl ether tetracarboxylic acid dianhydride（a-ODPA） and 3,4＇-oxydianiline（3,4＇-ODA） with different molecular weights（degree of polymerization： n = 1？9） were formed. The resultant oligomers with different molecular weights were characterized for their chemical architecture, cure behavior, thermal properties, solubility in organic solvents and rheological characteristics. Besides, the thermal properties and tensile test of cured polyimide films were also evaluated. The imide oligomer（degree of polymerization： n = 1） has some somewhat crystalline phase, and imide oligomers（degree of polymerization： n = 2？9） showed excellent solubility（40 wt%） in N-methyl-2-pyrrolidone（NMP） and N,Ndimethylacetamide（DMAc） at room temperature. Furthermore, the rheological properties of imide oligomers showed very low melt viscosity and wider processing window. The cured films exhibited good thermal properties with the glass transition temperatures of 282？373 ？C and 5 wt% thermal decomposition temperatures higher than 551 ？C in nitrogen atmosphere. The elongation at break of the prepared films was found to be high（almost 〉 9.3%）.
基金supported by the National Natural Science Foundation of China(No.52273264)。
文摘Polymeric carbon nitride(PCN)has garnered increasing attention as a metal-free photocatalyst with a suitable band gap.In efforts to enhance its photocatalytic performance,researchers have examined various PCN materials,including poly(heptazine imide)(PHI)and poly(triazine imide)(PTI),two isomers within the PCN family that exhibit distinct and superior photocatalytic activity compared to other forms.The challenge,however,lies in the common practice among researchers to categorize PHI and PTI along with other PCN types under the overarching term“g-C_(3)N_(4),”which significantly impedes optimization efforts.The objective of this review is to provide comprehensive insights into the structural features,photoelectrochemical properties,and effective characterization methods employed for distinguishing between PHI and PTI materials.The review also summarizes various optimization strategies,such as crystallinity adjustments,defect engineering,morphology control,constructing heterojunction,and atomic-level metal loading dispersion,to elevate the photocatalytic activity of PHI and PTI,in addition to summarizing the history of carbon nitride development.Furthermore,this review highlights the primary applications of PHI and PTI,encompassing nitrogen fixation,biomass conversion,organic synthesis,CO_(2)reduction,pollutant degradation,H_(2)O_(2)production,and photocatalytic water splitting.Lastly,the prospects and challenges associated with further advancing PHI and PTI are thoroughly examined.
基金supported by the National Key Research and Development Program of China(2018YFB1502003)the National Natural Science Foundation of China(51961165103)supported by the National Program for Support of Top-notch Young Professionals and‘‘The Youth Innovation Team of Shaanxi Universities”。
文摘Carbon nitride-based photocatalysts hold an enormous potential in producing hydrogen.A strategy to simultaneously create isotype heterojunctions and active sites in highly-crystallized carbon nitride is anticipated to significantly boost the photocatalytic activity,but is yet to be realized.Herein,we find that cobalt salt added in the ionothermal synthesis can promote the phase transition of heptazine-based crystalline carbon nitride(CCN)to triazine-based poly(triazine imide)(PTI),rendering the creation of singleatom cobalt coordinated isotype CCN/PTI heterojunction.Co-CCN/PTI exhibits an appreciable apparent quantum yield of 20.88%at 425 nm for photocatalytic hydrogen production with a rate achieving3538μmol h^(-1)g^(-1)(λ>420 nm),which is 4.8 times that of CCN and 27.6 times that of PTI.The high photocatalytic activity is attributed to the Type II isotype highly-crystallized CCN/PTI heterojunction for promoting charge carrier migration,and the single-atom Co sites for accelerating surface oxidation reaction.
基金a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute(KHIDI)the Ministry of Health&Welfare,Republic of Korea(grant number:HI18C0493).
文摘Poly(ether imide)(PEI)has shown satisfactory corrosion protection capability with good adhesion strength as a coating for magnesium(Mg),a potential candidate of biodegradable orthopedic implant material.However,its innate hydrophobic property causes insufficient osteoblast affinity and a lack of osseointegration.Herein,we modify the physical and chemical properties of a PEI-coated Mg implant.A plasma immersion ion implantation technique is combined with direct current(DC)magnetron sputtering to introduce biologically compatible tantalum(Ta)onto the surface of the PEI coating.The PEI-coating layer is not damaged during this process owing to the extremely short processing time(30 s),retaining its high corrosion protection property and adhesion stability.The Ta-implanted layer(roughly 10-nm-thick)on the topmost PEI surface generates long-term surface hydrophilicity and favorable surface conditions for pre-osteoblasts to adhere,proliferate,and differentiate.Furthermore,in a rabbit femur study,the Ta/PEI-coated Mg implant demonstrates significantly enhanced bone tissue affinity and osseointegration capability.These results indicate that Ta/PEI-coated Mg is promising for achieving early mechanical fixation and long-term success in biodegradable orthopedic implant applications.
基金supported by the National Natural Science Foundation of China (61604071, 61525402, 61604119, 61704131 and 61775095)Natural Science Foundation of Jiangsu Province (BK20161012)+1 种基金Postgraduate Research & Practice Innovation Program of Jiangsu Province (SJZZ16_0139)SICAM Scholarship (38600001)
文摘It is of great significance to design and synthesize highly efficient n-type organic small molecules as electron-transporting layer(ETL) materials to achieve high performance planar perovskite solar cells(PVKSCs) with lowtemperature solution-processing. In this article, acenaphthylene-imide based small molecules AI1, AI2 and AI3 were developed with lower-lying LUMO energy levels and were further applied as non-fullerene ETL materials for solutionprocessed PVKSCs. When TiO2/AIX bilayer was used as ETL,an average power conversion efficiency(PCE) of 15.0% was achieved for TiO2/AI1 based PVKSCs with conventional configuration, while pristine TiO2 based devices presented a PCE of 11.7% only. All the results demonstrate that acenaphthylene-imide derivatives could be promising ETL materials to accomplish low-temperature solution-processed high performance PVKSCs.
基金National Key R&D Program of China,Grant/Award Number:2021YFA1502100National Natural Science Foundation of China,Grant/Award Number:22172029Science Foundation of the Fujian Province,Grant/Award Number:2022L3084。
文摘Poly(heptazine imide)(PHI),a semicrystalline version of carbon nitride photocatalyst based on heptazine units,has gained significant attention for solar H_(2)production benefiting from its advantages including molecular synthetic versatility,excellent physicochemical stability and suitable energy band structure to capture visible photons.Typically,PHI is obtained in saltmelt synthesis in the presence of alkali metal chlorides.Herein,we examined the role of binary alkali metal bromides(LiBr/NaBr)with diverse compositions and melting points to rationally modulate the polymerization process,structure,and properties of PHI.Solid characterizations revealed that semicrystalline PHI with a condensedπ-conjugated system and rapid charge separation rates were obtained in the presence of LiBr/NaBr.Accordingly,the apparent quantum yield of hydrogen using the optimized PHI reaches up to 62.3%at 420 nm.The density functional theory calculation shows that the dehydrogenation of the ethylene glycol has a lower energy barrier than the dehydrogenation of the other alcohols from the thermodynamic point of view.This study holds great promise for rational modulation of the structure and properties of conjugated polymeric materials.
文摘A novel poly(ether imide)s containing phthalazinone and isopropyl moieties derived from 2-(4-aminophenyl)-4-[4-(4-aminophenoxy)phenyl]-phthalazin-1-one and bisphenol-A diphthalic anhydride was synthesized by one-step solution condensation polymerization in nr-cresol. The polymer was characterized by FTIR, NMR, molecular weights, glass transition temperature, thermal degradation temperature and WAXD.
文摘A series of novel aromatic poly ( amide imide)s containing phthalazinone moieties were prepared from 2-(4-aminophenyl)-4-[3-methyl-4-(4-aminophenoxy)-2,3-phthalazinone-1], a novel diamine 1 with four diimide-dicarboxylic acids by Yamazaki phosphorylation method with the inherent viscosity of 0.36~0.65 dL/g. These polymers had high glass transition temperatures above 300C and they lost 10% weight between 426~475C in N2. The structure of diamine 1 and the polymers was confirmed by IR, 1H NMR and MS. The obtained polymers were readily soluble in polar solvents such as NMP, m-cresol etc. and easily cast into tough, flexible films. The X-ray indicated that they are all amorphous.
