Proton conducting composite membranes from sulfonated polyether ether ketone and SiO2 for direct methanol fuel cell （DMFC） application were prepared with sulfonated polyether ether ketone（SPEEK） and tetracethoxy s...Proton conducting composite membranes from sulfonated polyether ether ketone and SiO2 for direct methanol fuel cell （DMFC） application were prepared with sulfonated polyether ether ketone（SPEEK） and tetracethoxy silane（TEOS） by sol-gel method. The covalent crosslinking structure was formed between —SO3H of SPEEK via SiO2. The SEM images show that the interfacial compatibility of SPEEK and SiO2 is improved obviously and SiO2 disperses uniformly in the polymer matrix and the particle diameter of SiO2 does not exceed 40 nm. The proton conductivity of composite membranes decreases slightly compared with the SPEEK membrane while the methanol permeability and swelling of composite membrane are improved remarkablely owing to covalent cross-linking between —SO3H and SiO2 .展开更多
Composite membranes based on sulfonated silica/sulfonated poly（ether ether ketone）（SPEEK） were prepared by means of sol-gel method so as to gain a high conductivity and reasonable methanol permeability.The sulfona...Composite membranes based on sulfonated silica/sulfonated poly（ether ether ketone）（SPEEK） were prepared by means of sol-gel method so as to gain a high conductivity and reasonable methanol permeability.The sulfonated silica is generated in situ via the hydrolysis of sulfonated 3-anminopropyl triethoxysilane（KH550） synthesized newly from 3-aminopropyl triethoxysilane and 1,4-butane sultone.The membrane with a silica mass fraction of 5% exhibits a conductivity of 0.187 S/cm at 80 °C and a methanol coefficient with 9.72×10-7 cm2/s.The composite membranes show improved condutive ability and better selectivity that can be promisingly used in direct methanol fuel cell.展开更多
Sulfonated polyether ether ketone （SPEEK） based composite membranes for direct methanol fuel cell （DMFC） application were prepared by sol-gel reaction of tetraethoxysilane （TEOS） in the SPEEK matrix and the inco...Sulfonated polyether ether ketone （SPEEK） based composite membranes for direct methanol fuel cell （DMFC） application were prepared by sol-gel reaction of tetraethoxysilane （TEOS） in the SPEEK matrix and the incorporation of phosphotungstic acid （PWA）.The conductivity of the developed membranes was determined by impedance spectroscopy and the methanol permeability through the membranes was obtained from diffuseness experiments.The SEM images show that the addition of SiO2 and the covalent cross-linking structure lead to fine PWA particles and more uniformly dispersion.The swelling of composite membranes remains in the range of 5%-8% at 30-90 ℃ and the effusion of PWA reduces significantly.The composite membranes show a good balance in higher proton conductivity and lower methanol permeation.The cell with composite membrane has higher open circuit voltage（0.728 V） and higher peak power density（45 mW/cm2） than that with Nafion117.展开更多
Sulfonated polyether ether ketone (SPEEK) with variou s degree of sulfonation (DS) were synthesized by reaction of PEEK with sulfo nic acid as sulfonating agent and solvent.Their proton conductivity and methanol pe rm...Sulfonated polyether ether ketone (SPEEK) with variou s degree of sulfonation (DS) were synthesized by reaction of PEEK with sulfo nic acid as sulfonating agent and solvent.Their proton conductivity and methanol pe rmeability as a function of the degree of sulfonation were investigated.For 46 .71% DS,proton conductivity was 1.68×10 -2S/cm at 80℃ and 4.25×10 -2S/cm at 100℃,which is closed to or superior to that of Nafion 115 me mbrane at the same conditions.Methanol permeability of SPEEK was considerable s maller than that of Nafion 115 membrane.Because of their high conductivity and low methanol permeability,SPEEK membranes appear to be excellent candidate for use in DMFC applications.展开更多
A novel inorganic-organic composite membrane based on sulfonated polyether ether ketone(SPEEK) with embedded phosphotungstic acid(PWA) for direct methanol fuel cells(DMFC) was prepared. IR spectra results indicate tha...A novel inorganic-organic composite membrane based on sulfonated polyether ether ketone(SPEEK) with embedded phosphotungstic acid(PWA) for direct methanol fuel cells(DMFC) was prepared. IR spectra results indicate that PWA was kept in SPEEK matrix as the Keggin structure. From SEM micrograph, it could be found that the solid PWA were well mixed with SPEEK matrix and showed no agglomeration in the membrane. Proton conductivity of the PWA/SPEEK composite membrane is higher than that of pure SPEEK membrane, and is similar or superior to that of Nafion ○R 115 membrane in the temperature range 80—110 ℃. Methanol permeability of the PWA/SPEEK membrane was considerably smaller than that of Nafion ○R 115 membrane. Because of its high conductivity and low methanol permeability, the PWA/SPEEK membrane seems to be an excellent candidate for DMFC applications.展开更多
文摘Proton conducting composite membranes from sulfonated polyether ether ketone and SiO2 for direct methanol fuel cell （DMFC） application were prepared with sulfonated polyether ether ketone（SPEEK） and tetracethoxy silane（TEOS） by sol-gel method. The covalent crosslinking structure was formed between —SO3H of SPEEK via SiO2. The SEM images show that the interfacial compatibility of SPEEK and SiO2 is improved obviously and SiO2 disperses uniformly in the polymer matrix and the particle diameter of SiO2 does not exceed 40 nm. The proton conductivity of composite membranes decreases slightly compared with the SPEEK membrane while the methanol permeability and swelling of composite membrane are improved remarkablely owing to covalent cross-linking between —SO3H and SiO2 .
基金Supported by the National High-Tech Research and Development Program of China(No.2007AA03Z218)
文摘Composite membranes based on sulfonated silica/sulfonated poly（ether ether ketone）（SPEEK） were prepared by means of sol-gel method so as to gain a high conductivity and reasonable methanol permeability.The sulfonated silica is generated in situ via the hydrolysis of sulfonated 3-anminopropyl triethoxysilane（KH550） synthesized newly from 3-aminopropyl triethoxysilane and 1,4-butane sultone.The membrane with a silica mass fraction of 5% exhibits a conductivity of 0.187 S/cm at 80 °C and a methanol coefficient with 9.72×10-7 cm2/s.The composite membranes show improved condutive ability and better selectivity that can be promisingly used in direct methanol fuel cell.
基金Funded by Ministry of Education, Hubei, China (No.Q20091403)
文摘Sulfonated polyether ether ketone （SPEEK） based composite membranes for direct methanol fuel cell （DMFC） application were prepared by sol-gel reaction of tetraethoxysilane （TEOS） in the SPEEK matrix and the incorporation of phosphotungstic acid （PWA）.The conductivity of the developed membranes was determined by impedance spectroscopy and the methanol permeability through the membranes was obtained from diffuseness experiments.The SEM images show that the addition of SiO2 and the covalent cross-linking structure lead to fine PWA particles and more uniformly dispersion.The swelling of composite membranes remains in the range of 5%-8% at 30-90 ℃ and the effusion of PWA reduces significantly.The composite membranes show a good balance in higher proton conductivity and lower methanol permeation.The cell with composite membrane has higher open circuit voltage（0.728 V） and higher peak power density（45 mW/cm2） than that with Nafion117.
文摘Sulfonated polyether ether ketone (SPEEK) with variou s degree of sulfonation (DS) were synthesized by reaction of PEEK with sulfo nic acid as sulfonating agent and solvent.Their proton conductivity and methanol pe rmeability as a function of the degree of sulfonation were investigated.For 46 .71% DS,proton conductivity was 1.68×10 -2S/cm at 80℃ and 4.25×10 -2S/cm at 100℃,which is closed to or superior to that of Nafion 115 me mbrane at the same conditions.Methanol permeability of SPEEK was considerable s maller than that of Nafion 115 membrane.Because of their high conductivity and low methanol permeability,SPEEK membranes appear to be excellent candidate for use in DMFC applications.
文摘A novel inorganic-organic composite membrane based on sulfonated polyether ether ketone(SPEEK) with embedded phosphotungstic acid(PWA) for direct methanol fuel cells(DMFC) was prepared. IR spectra results indicate that PWA was kept in SPEEK matrix as the Keggin structure. From SEM micrograph, it could be found that the solid PWA were well mixed with SPEEK matrix and showed no agglomeration in the membrane. Proton conductivity of the PWA/SPEEK composite membrane is higher than that of pure SPEEK membrane, and is similar or superior to that of Nafion ○R 115 membrane in the temperature range 80—110 ℃. Methanol permeability of the PWA/SPEEK membrane was considerably smaller than that of Nafion ○R 115 membrane. Because of its high conductivity and low methanol permeability, the PWA/SPEEK membrane seems to be an excellent candidate for DMFC applications.
