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
Cyclic oligomers of phenolphthalein polyarylene ether sulfone(ketone) were prepared through cyclo-depolymerisation of corresponding polymers using CsF as the catalyst in dipolar aprotic solvent DMAc and DMF, and a fam...Cyclic oligomers of phenolphthalein polyarylene ether sulfone(ketone) were prepared through cyclo-depolymerisation of corresponding polymers using CsF as the catalyst in dipolar aprotic solvent DMAc and DMF, and a family of macrocycles containing from dimer up to at least heptamer were confirmed by GPC, HPLC and MALDI-TOF-MS. The yields of cyclics get as high as 86.3% and 87.9% respectively.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 .
文摘Cyclic oligomers of phenolphthalein polyarylene ether sulfone(ketone) were prepared through cyclo-depolymerisation of corresponding polymers using CsF as the catalyst in dipolar aprotic solvent DMAc and DMF, and a family of macrocycles containing from dimer up to at least heptamer were confirmed by GPC, HPLC and MALDI-TOF-MS. The yields of cyclics get as high as 86.3% and 87.9% respectively.
