论文部分内容阅读
A sulfonated poly(ether ether ketone)(SPEEK) membrane with fairly high degree of sulfonation(DS) swells excessively and even dissolves at high temperature.To solve these problems,sulfonated phenolphthalein poly(ether sulfone)(SPES-C,DS = 53.7%) is blended with the SPEEK matrix(DS = 55.1%,61.7%) to prepare SPEEK/SPES-C blend membrane.The decrease in swelling degree and methanol permeability of the membrane is dose-dependent.Pure SPEEK(DS = 61.7%) membrane dissolves completely in water at 70oC,whereas the swelling degree of the SPEEK(DS = 61.7%)/SPES-C(40%,by mass) membrane is 29.7% at 80oC.From room temperature to 80oC,the methanol permeability of all SPEEK(DS = 55.1%)/SPES-C blend membranes is about one order of magnitude lower than that of Nafion115.At higher temperature,the addition of SPES-C polymer increases the dimensional stability and greater proton conductivity can be achieved.The SPEEK(DS = 55.1%)/SPES-C(40%,by mass) membrane can withstand temperatures up to 150oC.The proton conductivity of SPEEK(DS = 55.1%)/SPES-C(30%,by mass) membrane approaches 0.16 S.cm-1,matching that of Nafion 115 at 140oC and 100% RH,while pure SPEEK(DS = 55.1%) membrane dissolves at 90oC.The SPEEK/SPES-C blend membranes are promising for use in direct methanol fuel cells because of their good dimensional stability,high proton conductivity,and low methanol permeability.
Sulfonated polyether ether ketone (SPEEK) membranes with fairly high degree of sulfonation (DS) swells excessively and even dissolves at high temperatures. To solve these problems, sulfonated phenolphthalein polyether sulfone (SPES-C, DS = 53.7 %) was blended with the SPEEK matrix (DS = 55.1%, 61.7%) to prepare SPEEK / SPES-C blend membrane. The decrease in swelling degree and methanol permeability of the membrane is dose- dependent. Pure SPEEK (DS = 61.7% ) membrane dissolves completely in water at 70oC, while the swelling degree of the SPEEK (DS = 61.7%) / SPES-C (40% by mass) membrane is 29.7% at 80oC. all SPEEK (DS = 55.1%) / SPES-C blend membranes is about one order of magnitude lower than that of Nafion® 115.At higher temperature, the addition of SPES-C polymer increases the dimensional stability and greater proton conductivity can be achieved The SPEEK (DS = 55.1%) / SPES-C (40%, by mass) membrane can withstand temperatures up to 150oC. The proto n conductivity of SPEEK (DS = 55.1%) / SPES-C (30%, by mass) membrane approaches 0.16 S.cm- 1, matching that of Nafion® 115 at 140 ° C. and 100% RH, while pure SPEEK %) membrane dissolves at 90oC. The SPEEK / SPES-C blend membranes are promising for use in direct methanol fuel cells because of their good dimensional stability, high proton conductivity, and low methanol permeability.