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
A novel crosslinkable fluorinated poly(ether ether ketone) with acetylenylbenzene end groups was prepared by solution condensation. The chemical structure of such polymer was confirmed by FTIR and 1H NMR. The crosslin...A novel crosslinkable fluorinated poly(ether ether ketone) with acetylenylbenzene end groups was prepared by solution condensation. The chemical structure of such polymer was confirmed by FTIR and 1H NMR. The crosslinking behavior and thermal stability were investigated by DSC and TGA respectively. The DSC thermogram for the first heating run shows a glass transition of 6F-PEEK at about 395 K and a exothermic peak correspongding to the self-crosslinking reaction of fluorinated poly(ether ether ketong) at about 700 K. For the second heating run, the exothermic peak disappered and the glass transition shifted to a higher temperature. The crosslinked polymer shown excelent thermal stability and solvent-resistence. The temperature for 5% weight loss was 774 K and the self-crosslinked polymer was no more disolved by polar solvents, which disolved in before crosslinking, such as DMF, DMAc and NMP. This kind of polymer may be a potential material used as electro-optical devices.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.
文摘A novel crosslinkable fluorinated poly(ether ether ketone) with acetylenylbenzene end groups was prepared by solution condensation. The chemical structure of such polymer was confirmed by FTIR and 1H NMR. The crosslinking behavior and thermal stability were investigated by DSC and TGA respectively. The DSC thermogram for the first heating run shows a glass transition of 6F-PEEK at about 395 K and a exothermic peak correspongding to the self-crosslinking reaction of fluorinated poly(ether ether ketong) at about 700 K. For the second heating run, the exothermic peak disappered and the glass transition shifted to a higher temperature. The crosslinked polymer shown excelent thermal stability and solvent-resistence. The temperature for 5% weight loss was 774 K and the self-crosslinked polymer was no more disolved by polar solvents, which disolved in before crosslinking, such as DMF, DMAc and NMP. This kind of polymer may be a potential material used as electro-optical devices.
