A ternary hybrid membrane architecture consisting of sulfonated fluorinated multi-block copolymer （SFMC）, sulfonated （poly ether ether ketone） （SPEEK） and I or 5 wt% graphene oxide （GO） was fabricated through ...A ternary hybrid membrane architecture consisting of sulfonated fluorinated multi-block copolymer （SFMC）, sulfonated （poly ether ether ketone） （SPEEK） and I or 5 wt% graphene oxide （GO） was fabricated through a facile solution casting approach. The simple, but effective monomer sulfonation was performed for SFMC to create compact and rigid hydrophobic backbone structures, while conventional random sulfonation was carried-out for SPEEK. Hydrophilic-hydrophobic-hydrophilic structure of SFMC enhances the compatibility with SPEEK and GO and allows for an unprecedented approach to alter me- chanical strength and proton conductivity of ternary hybrid membrane, as verified from universal test machine （UTM） curves and alternating current （AC） impedance plots. The impact of GO integration on the morphology and roughness of hybrid membrane was scrutinized using field emission scanning electron microscope （FE-SEM） and atomic force microscope （AFM）. Ternary hybrid showed uniform intercalation of GO nanosheets throughout the entire surface of membrane with an increased surface roughness of 8.91 nm. The constructed ternary hybrid membrane revealed excellent water absorption, ion exchange capacity and gas barrier properties, while retaining reasonable dimensional stability. The well-optimized ternary hybrid membrane containing 5 wt% GO revealed a maximum proton conductivity of 111.9 mS/cm, which is higher by a factor of two-fold with respect to that of bare SFMC membrane. The maximum PEMFC power density of 528.07mW/cm2 was yielded by ternary hybrid membrane at a load current density of 1321.1 mA/cm2 when operating the cell at 70 ℃ under 100% relative humidity （RH）. In comparison, a maximum power density of only 182.06 mW/cm2 was exhibited by the bare SFMC membrane at a load current density of 455.56 mA/cm2 under same operating conditions.展开更多
We employed the extended self-consistent field theory to investigate the supramolecular self-assembly behaviors of asymmetric diblock copolymer blends(AB/B’C)with hydrogen bonding interactions between shorter B and B...We employed the extended self-consistent field theory to investigate the supramolecular self-assembly behaviors of asymmetric diblock copolymer blends(AB/B’C)with hydrogen bonding interactions between shorter B and B’blocks.The hydrogen bonding interactions are described by Yukawa potentials,where the hydrogen bonding donors and acceptors were modelled as two blocks smeared with opposite screened charges.The hierarchical microstructures with parallelly packed lamellae-in-lamellae(Lam)and 4.8.8 Archimedean tilting pattern(4.8.8)were observed at lower and higher hydrogen bonding density(θ),respectively.The hierarchy of Lam and 4.8.8 were demonstrated by the one-and two-dimensional density profiles and the underlying order of the large-length-scale and small-length-scale microstructures were also clarified.It was found that the 4.8.8 is favorable to the stronger hydrogen bonding density or interactions.Asθincreases,the microphase transition from Lam to 4.8.8 occurs atθ=0.34,which is mainly attributed to the optimization of the electrostatic energy and conformational entropy with sacrificing the interfacial energy.This work can provide a new strategy to understand the supramolecular self-assembly as well as the mechanism behind the formation of complex hierarchical microstructures.展开更多
Supramolecular assemblies （PS-b-P4VP （AzoR）） are fabricated by hydrogen-bonding azobenzene derivatives （AzoR） to poly（4-vinyl pyridine） blocks of polystyrene-block-poly（4-vinyl pyridine） （PS-b-P4VP）. PS-b-...Supramolecular assemblies （PS-b-P4VP （AzoR）） are fabricated by hydrogen-bonding azobenzene derivatives （AzoR） to poly（4-vinyl pyridine） blocks of polystyrene-block-poly（4-vinyl pyridine） （PS-b-P4VP）. PS-b-P4VP（AzoR） forms phase separated nanostructures with a period of-75-105 nm. A second length scale structure with a period of 2μm is fabricated on phase separated PS-b-P4VP（AzoR） by laser interference abla- tion. Both the concentration and the substituent of AzoR in PS-b-P4VP（AzoR） affect the laser ablation process. The laser ablation threshold of PS-b-P4VP（AzoR） decreases as the concentration of AzoR increases. In PS-b-P4VP（AzoR） with different substituents （R = CN, H, and CH3）, ablation thresholds follow the trend： PS-b-P4VP（AzoCN）〈 PS-b- P4VP（AzoCH3）〈PS-b-P4VP（AzoH）. This result indicates that the electron donor group （CH3） and the electron acceptor group （CN） can lower the ablation threshold of PS-b-P4VP（AzoR）.展开更多
基金supported by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)the Ministry of Trade,Industry&Energy(MOTIE)of the Republic of Korea(No.20164030201070)supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT and future Planning(NRF-2017R1A2B4005230)
文摘A ternary hybrid membrane architecture consisting of sulfonated fluorinated multi-block copolymer （SFMC）, sulfonated （poly ether ether ketone） （SPEEK） and I or 5 wt% graphene oxide （GO） was fabricated through a facile solution casting approach. The simple, but effective monomer sulfonation was performed for SFMC to create compact and rigid hydrophobic backbone structures, while conventional random sulfonation was carried-out for SPEEK. Hydrophilic-hydrophobic-hydrophilic structure of SFMC enhances the compatibility with SPEEK and GO and allows for an unprecedented approach to alter me- chanical strength and proton conductivity of ternary hybrid membrane, as verified from universal test machine （UTM） curves and alternating current （AC） impedance plots. The impact of GO integration on the morphology and roughness of hybrid membrane was scrutinized using field emission scanning electron microscope （FE-SEM） and atomic force microscope （AFM）. Ternary hybrid showed uniform intercalation of GO nanosheets throughout the entire surface of membrane with an increased surface roughness of 8.91 nm. The constructed ternary hybrid membrane revealed excellent water absorption, ion exchange capacity and gas barrier properties, while retaining reasonable dimensional stability. The well-optimized ternary hybrid membrane containing 5 wt% GO revealed a maximum proton conductivity of 111.9 mS/cm, which is higher by a factor of two-fold with respect to that of bare SFMC membrane. The maximum PEMFC power density of 528.07mW/cm2 was yielded by ternary hybrid membrane at a load current density of 1321.1 mA/cm2 when operating the cell at 70 ℃ under 100% relative humidity （RH）. In comparison, a maximum power density of only 182.06 mW/cm2 was exhibited by the bare SFMC membrane at a load current density of 455.56 mA/cm2 under same operating conditions.
基金financially supported by the Natural Science Foundation of Shanghai(No.21ZR1402800)the Fundamental Research Funds for the Central Universities(No.2232020D-11)+1 种基金the China Postdoctoral Science Foundation(No.2021M690597)the Open Project Program of Fujian Provincial Key Laboratory of Textiles Inspection Technology(Fujian Fiber Inspection Center)(Nos.2020-MXJ-04)。
文摘We employed the extended self-consistent field theory to investigate the supramolecular self-assembly behaviors of asymmetric diblock copolymer blends(AB/B’C)with hydrogen bonding interactions between shorter B and B’blocks.The hydrogen bonding interactions are described by Yukawa potentials,where the hydrogen bonding donors and acceptors were modelled as two blocks smeared with opposite screened charges.The hierarchical microstructures with parallelly packed lamellae-in-lamellae(Lam)and 4.8.8 Archimedean tilting pattern(4.8.8)were observed at lower and higher hydrogen bonding density(θ),respectively.The hierarchy of Lam and 4.8.8 were demonstrated by the one-and two-dimensional density profiles and the underlying order of the large-length-scale and small-length-scale microstructures were also clarified.It was found that the 4.8.8 is favorable to the stronger hydrogen bonding density or interactions.Asθincreases,the microphase transition from Lam to 4.8.8 occurs atθ=0.34,which is mainly attributed to the optimization of the electrostatic energy and conformational entropy with sacrificing the interfacial energy.This work can provide a new strategy to understand the supramolecular self-assembly as well as the mechanism behind the formation of complex hierarchical microstructures.
文摘Supramolecular assemblies （PS-b-P4VP （AzoR）） are fabricated by hydrogen-bonding azobenzene derivatives （AzoR） to poly（4-vinyl pyridine） blocks of polystyrene-block-poly（4-vinyl pyridine） （PS-b-P4VP）. PS-b-P4VP（AzoR） forms phase separated nanostructures with a period of-75-105 nm. A second length scale structure with a period of 2μm is fabricated on phase separated PS-b-P4VP（AzoR） by laser interference abla- tion. Both the concentration and the substituent of AzoR in PS-b-P4VP（AzoR） affect the laser ablation process. The laser ablation threshold of PS-b-P4VP（AzoR） decreases as the concentration of AzoR increases. In PS-b-P4VP（AzoR） with different substituents （R = CN, H, and CH3）, ablation thresholds follow the trend： PS-b-P4VP（AzoCN）〈 PS-b- P4VP（AzoCH3）〈PS-b-P4VP（AzoH）. This result indicates that the electron donor group （CH3） and the electron acceptor group （CN） can lower the ablation threshold of PS-b-P4VP（AzoR）.
