摘要
在磺化度(DS)为55.1%的磺化聚醚醚酮(SPEEK)中掺杂功能化二氧化硅(吸湿性SiO2溶胶及带有磺酸基团的二氧化硅(SiOx-S)粒子)制备SPEEK/SiO2和SPEEK/SiOx-S复合质子交换膜.SiO2和SiOx-S的掺杂能有效提高复合膜的抗溶胀、阻醇性能及高温低湿情况下的电导率.纯SPEEK膜在80℃溶胀为52.6%,而SiO2和SiOx-S掺杂量为15%的复合膜在此温度下分别仅有26.2%和27.3%的溶胀.在室温至80℃范围内,SPEEK/SiO2(20 wt%)和SPEEK/SiOx-S(20 wt%)复合膜的甲醇透过系数比Nafion115膜小近2个数量级.在120℃、相对湿度(RH)为40%情况下,SPEEK纯膜的电导率仅为2.6×10-4S.cm-1,SPEEK/SiO2(20 wt%)复合膜约为2.0×10-3S.cm-1,而SPEEK/SiOx-S(20 wt%)复合膜高达1.0×10-2S.cm-1,与Nafion115相当.SPEEK/SiO2(20 wt%)和SPEEK/SiOx-S(20 wt%)2种复合膜的尺寸稳定性较高,膜电极无催化剂与膜分离现象,其DMFCs单电池性能好于SPEEK膜.
The present paper focuses on improving the water-holding ability of sulfonated poly (ether ether ketone) (SPEEK) (degree of sulfonation, DS = 55. 1% ) membranes. Funetionalized silica ( silica sol (SiO2) and silica powder with sulfonic acid groups (SiO-S)) were chosen as the hygroscopic additive, respectively. SPEEK/SiO2, SPEEK/SiOx-S composite membranes were obtained by casting a homogeneous mixture of SiO2 (or SiOx-S) and SPEEK in N,N-dimethylacetamide onto glass plate and then evaporating the solvent at 60℃. The decrease in both the swelling degree and the methanol permeability and the improvement in the conductivity at a high temperature and a low humidity of the membranes were a dose-dependent result of addition of the SiO2 and SiOx-S powders. Pure SPEEK membranes swelled 52.6% at 80℃ , whereas the SPEEK/SiO2(15 wt%) and SPEEK/SiO-S (15 wt%) membranes swelled only 26.2% and 27.3% at the same temperature,respectively. From room temperature to 80℃ , SPEEK/SiO2 (20 wt% ) and SPEEK/SiOx-S (20 wt% ) membranes had methanol permeability of about two order of magnitude lower than that of Nafion 115. At 120℃ and 40% relative humidity (RH),the conductivity of pure SPEEK membranes is only 2.6×10-4S·cm -1,and that of SPEEK/SiO2(20 wt%) membranes is about 2.0×10-3 S·cm-1,while that of SPEEK/SiOx-S (20 wt% ) composite membranes reaches 1.0×10-2 S·cm-1, which is close to that of Nafion115. DMFCs single cell performance of SPEEK/SiO2 (20 wt% ) and SPEEK/SiO -S (20 wt% ) membranes was better than that of pure SPEEK membranes because they had good dimensional stability and no separation of catalyzers and membranes in membrane electrode assembles.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2012年第6期640-647,共8页
Acta Polymerica Sinica
基金
国家重点基础研究发展计划(973计划
项目号2008CB617502)资助
关键词
磺化聚醚醚酮
复合膜
功能化二氧化硅
直接甲醇燃料电池
Sulfonated poly(ether ether ketone ), Composite membrane, Functionalized silica, Direct methanol fuel cell