A sulfonated poly(ether ether ketone)(SPEEK) membrane with a fairly high degree of sulfonation(DS) can swell excessively and even dissolve at high temperature.To solve these problems,insolvable functionalized silica p...A sulfonated poly(ether ether ketone)(SPEEK) membrane with a fairly high degree of sulfonation(DS) can swell excessively and even dissolve at high temperature.To solve these problems,insolvable functionalized silica powder with sulfonic acid groups(SiOx-S) was added into the SPEEK matrix(DS = 55.1%) to prepare SPEEK/SiOx-S composite membranes.The decrease in both the swelling degree and the methanol permeability of the membranes was a dose-dependent result of addition of the SiOx-S powder.Pure SPEEK membrane swelled 52.6% at 80°C,whereas the SPEEK/SiOx-S(15%,by mass) membrane swelled only 27.3% at the same temperature.From room temperature to 80℃,all SPEEK/SPEEK/SiOx-S composite membranes had methanol permeability of about o ne order of magnitude lower than that of Nafion?115.Compared with pure SPEEK membranes,the addition of the SiOx-S powder not only leads to higher proton conductivity,but also increases the dimensional stability at higher temperatures,and greater proton conductivity can be achieved at higher temperature.The SPEEK/SiOx-S(20%,by mass) membrane could withstand temperature up to 145°C,at which in 100% relative humidity(RH) its proton conductivity exceeded slightly that of Nafion?115 membrane and reached 0.17 S·cm-1,while pure SPEEK membrane dissolved at 90°C.The SPEEK/SiOx-S composite membranes are promising for use in direct methanol fuel cells because of their good dimensional stability,high proton conductivity,and low methanol permeability.展开更多
Sulfonated poly(ether ether ketone)(SPEEK)is a very promising alternative membrane material for direct methanol fuel cells.However,with a fairly high degree of sulfonation(DS),SPEEK membranes can swell excessively and...Sulfonated poly(ether ether ketone)(SPEEK)is a very promising alternative membrane material for direct methanol fuel cells.However,with a fairly high degree of sulfonation(DS),SPEEK membranes can swell excessively and even dissolve at high temperature.This restricts mem-branes from working above a high tolerable temperature to get high proton conductivity.To deal with this contra-dictory situation,insolvable zirconium tricarboxybutyl-phosphonate(Zr(PBTC))powder was employed to make a composite with SPEEK polymer in an attempt to improve temperature tolerance of the membranes.SPEEK/Zr(PBTC)composite membranes were obtained by casting a homogeneous mixture of Zr(PBTC)and SPEEK in N,N-dimethylacetamide on a glass plate and then evaporating the solvent at 60℃.Many characteristics were investigated,including thermal stability,liquid uptake,methanol permeability and proton conductivity.Results showed significant improvement not only in tem-perature tolerance,but also in methanol resistance of the SPEEK/Zr(PBTC)composite membranes.The mem-branes containing 30 wt-%,40 wt-% of Zr(PBTC)had their methanol permeability around 10^(-7) cm^(2)·s^(-1) at room temperature to 80℃,which was one order of magnitude lower than that of Nafion H 115.High proton conductivity of the composite membranes,however,could also be achieved from higher temperature applied.At 100% rela-tive humidity,above 90℃ the conductivity of the compo-site membrane containing 40 wt-% of Zr(PBTC)exceeded that of the Nafion H 115 membrane and even reached a high value of 0.36 S·cm^(-1) at 160uC.Improved applicable tem-perature and high conductivity of the composite membrane indicatedits promisingapplication in DMFC operationsat high temperature.展开更多
Low methanol permeability of proton exchange membranes (PEMs) is greatly important for direct methanol fuel cells (DMFCs). Here, sulfonated poly (ether ether ketone) (SPEEK) based semiinterpenetrating polymer networks...Low methanol permeability of proton exchange membranes (PEMs) is greatly important for direct methanol fuel cells (DMFCs). Here, sulfonated poly (ether ether ketone) (SPEEK) based semiinterpenetrating polymer networks (semi-IPNs) are successfully prepared by interpenetrating SPEEK into the in-situ synthesized crosslinking networks. The polymeric networks are formed by the covalent bonds between bromobenzyl groups of bro mo methylated poly (phenylene oxide) and amine groups of diamine linkers as well as the ionic bonds between amine species and sulfonated groups. Two linkers without and with sulfonated groups are applied to fabricate the semi-IPNs. The core properties of the membranes, like phase separation, water uptake, proton conductivity and methanol permeability, are systematically studied and compared. The DMFCs assembled by using the semi-IPN membranes display better performance than Nafion 117 in high concentration methanol solutions. The present work provides a facile way to prepare PEMs with enhanced DMFC performance.展开更多
In order to improve the property of sulfonated poly(pathalazinone ether ketone)(SPPEK)membrane of high sulfonation degree,proton conductor zirconium tricarboxybutylphosphonate[Zr(PBTC)]was used and incorporated into S...In order to improve the property of sulfonated poly(pathalazinone ether ketone)(SPPEK)membrane of high sulfonation degree,proton conductor zirconium tricarboxybutylphosphonate[Zr(PBTC)]was used and incorporated into SPPEK to prepare Zr(PBTC)/SPPEK composite membranes for direct methanol fuel cell(DMFC).The results showed that the additive could reduce the water swelling and methanol permeability of membranes efficiently without sacrificing its conductivity.DMFC single cell performance demonstrated that the 30%(mass)Zr(PBTC)/SPPEK composite membrane was better than the pristine SPPEK membrane for its reduced swelling and consequently improved dimensional stability.展开更多
基金Supported by the State Key Development Program for Basic Research of China （2008CB617502）, the National Natural Science Foundation of China （20606025）, and Program for Changjiang Scholars and Innovative Research Team in University of China （IRT0641）.
文摘A sulfonated poly(ether ether ketone)(SPEEK) membrane with a fairly high degree of sulfonation(DS) can swell excessively and even dissolve at high temperature.To solve these problems,insolvable functionalized silica powder with sulfonic acid groups(SiOx-S) was added into the SPEEK matrix(DS = 55.1%) to prepare SPEEK/SiOx-S composite membranes.The decrease in both the swelling degree and the methanol permeability of the membranes was a dose-dependent result of addition of the SiOx-S powder.Pure SPEEK membrane swelled 52.6% at 80°C,whereas the SPEEK/SiOx-S(15%,by mass) membrane swelled only 27.3% at the same temperature.From room temperature to 80℃,all SPEEK/SPEEK/SiOx-S composite membranes had methanol permeability of about o ne order of magnitude lower than that of Nafion?115.Compared with pure SPEEK membranes,the addition of the SiOx-S powder not only leads to higher proton conductivity,but also increases the dimensional stability at higher temperatures,and greater proton conductivity can be achieved at higher temperature.The SPEEK/SiOx-S(20%,by mass) membrane could withstand temperature up to 145°C,at which in 100% relative humidity(RH) its proton conductivity exceeded slightly that of Nafion?115 membrane and reached 0.17 S·cm-1,while pure SPEEK membrane dissolved at 90°C.The SPEEK/SiOx-S composite membranes are promising for use in direct methanol fuel cells because of their good dimensional stability,high proton conductivity,and low methanol permeability.
基金Supported by the State Key Development Program for Basic Research of China （2008CB617502）, the National Natural Science Foundation of China （20606025）, and Program for Changjiang Scholars and Innovative Research Team in University of China （IRT0641）.
基金Science Foundation of China(The Youth Fund)(20606025)the science and technology development plan of Tianjin(05YFJZCOO600)Program fro Changjiang Scholars and Innova-tive Research Team in University(PCSIRT)for financial support.
文摘Sulfonated poly(ether ether ketone)(SPEEK)is a very promising alternative membrane material for direct methanol fuel cells.However,with a fairly high degree of sulfonation(DS),SPEEK membranes can swell excessively and even dissolve at high temperature.This restricts mem-branes from working above a high tolerable temperature to get high proton conductivity.To deal with this contra-dictory situation,insolvable zirconium tricarboxybutyl-phosphonate(Zr(PBTC))powder was employed to make a composite with SPEEK polymer in an attempt to improve temperature tolerance of the membranes.SPEEK/Zr(PBTC)composite membranes were obtained by casting a homogeneous mixture of Zr(PBTC)and SPEEK in N,N-dimethylacetamide on a glass plate and then evaporating the solvent at 60℃.Many characteristics were investigated,including thermal stability,liquid uptake,methanol permeability and proton conductivity.Results showed significant improvement not only in tem-perature tolerance,but also in methanol resistance of the SPEEK/Zr(PBTC)composite membranes.The mem-branes containing 30 wt-%,40 wt-% of Zr(PBTC)had their methanol permeability around 10^(-7) cm^(2)·s^(-1) at room temperature to 80℃,which was one order of magnitude lower than that of Nafion H 115.High proton conductivity of the composite membranes,however,could also be achieved from higher temperature applied.At 100% rela-tive humidity,above 90℃ the conductivity of the compo-site membrane containing 40 wt-% of Zr(PBTC)exceeded that of the Nafion H 115 membrane and even reached a high value of 0.36 S·cm^(-1) at 160uC.Improved applicable tem-perature and high conductivity of the composite membrane indicatedits promisingapplication in DMFC operationsat high temperature.
基金support of the National Natural Science Foundation of China(Nos. 21603197, 21703212,21233006 and 21473164)Natural Science Foundation of Hubei Province of China(No.2016CFB181)+1 种基金Fundamental Research Funds for the Central University, China University of Geosciences (Wuhan)(No. CUGL180403)China University of Geosciences (Wuhan) for the program of Center for Advanced Energy Research and Technologies
文摘Low methanol permeability of proton exchange membranes (PEMs) is greatly important for direct methanol fuel cells (DMFCs). Here, sulfonated poly (ether ether ketone) (SPEEK) based semiinterpenetrating polymer networks (semi-IPNs) are successfully prepared by interpenetrating SPEEK into the in-situ synthesized crosslinking networks. The polymeric networks are formed by the covalent bonds between bromobenzyl groups of bro mo methylated poly (phenylene oxide) and amine groups of diamine linkers as well as the ionic bonds between amine species and sulfonated groups. Two linkers without and with sulfonated groups are applied to fabricate the semi-IPNs. The core properties of the membranes, like phase separation, water uptake, proton conductivity and methanol permeability, are systematically studied and compared. The DMFCs assembled by using the semi-IPN membranes display better performance than Nafion 117 in high concentration methanol solutions. The present work provides a facile way to prepare PEMs with enhanced DMFC performance.
文摘In order to improve the property of sulfonated poly(pathalazinone ether ketone)(SPPEK)membrane of high sulfonation degree,proton conductor zirconium tricarboxybutylphosphonate[Zr(PBTC)]was used and incorporated into SPPEK to prepare Zr(PBTC)/SPPEK composite membranes for direct methanol fuel cell(DMFC).The results showed that the additive could reduce the water swelling and methanol permeability of membranes efficiently without sacrificing its conductivity.DMFC single cell performance demonstrated that the 30%(mass)Zr(PBTC)/SPPEK composite membrane was better than the pristine SPPEK membrane for its reduced swelling and consequently improved dimensional stability.
