原位聚合法制备Nafion~/PANI复合膜及其在DMFC中的应用

Nafion~/PANI composite membranes by in situ polymerization for direct methanol fuel cell

用0.1mol／L（NH4）2S2O8／1 mol／L盐酸溶液作引发剂，采用原位化学聚合的方法将苯胺单体聚合在Nation 112膜基体中．扫描电镜（SEM）和能谱（EDX）测试结果表明，复合膜的表面和Nafion 112膜相比有明显变化，苯胺主要聚合在膜的两侧．复合膜的红外光谱中出现明显聚苯胺（PANI）的特征吸收峰说明，苯胺成功地聚合在Nation 112膜中．完全湿润状态下复合膜的质子电导率和Nation 112膜相比有少许下降．甲醇渗透性能测试表明，复合膜具有明显的阻醇作用，NF／PANI-2膜的甲醇渗透率值是1．83×10^-6 cm^2／s和Nation。112膜相比降低了44％．相应地由NF／PANI-2膜组装的直接甲醇燃料电池（DMFC）开路电压值比Nafion 112膜的提高了7％，最大功率密度提高了30％．

Aniline monomer had been polymerized in Nafion 112 membrane using （0. 1 mol/L）（NH4）2S2O8/1 mol/LHCl solution as oxidant by an in situ chemical polymerization method. Scanning electron microscopy （SEM） and energy-dispersive X-ray spectroscopy （EDX） measurements indicated that there was an obvious difference between the plane of the composite membrane and Nafion 112 membrane. Polyaniline （PANI） was mainly located in the two sides of the membrane. FT-IR spectroscopy of the composite membrane showed that the characteristic bands of PANI can be observed in it which meant PANI was successfully polymerized in Nation 112 membrane. The proton conductivity of composite membrane was slightly lower than that of Nation 112 membrane under completely humidity conditions, but the methanol crossover of composite membranes was obviously reduced. The permeability of NF/PANI-2 membrane was 1.83 10^-6 cm^2/s which was 44% lower than that of Nation 112 membrane. Correspondingly the direct methanol fuel cell （DMFC） with NF/PANI-2 membrane has a 7% higher open circuit voltage （OCV） and 30% higher maximum power density than that of Nation 112 membrane.