燃料电池用聚芳醚砜阴离子交换膜的制备及性能研究瘤-化学工程专业毕业论文.docx

AbstractProton Abstract Proton exchange membrane fuel cells(PEMFCs)have become one of the most promising energy—conversion devices due to their high power density,high energy conversion efficiency,environmental friendliness and ease of fuel supplement．Proton exchange membranes(PEMs)，the key components for PEMFCs，have been extensively studied．However,the widespread commercialization of PEMFCs is impeded by the high fuel permeability of PEM and exclusive dependence on expensive Pt—based catalysts．Anion exchange membranes(AEMs)based fuel cells，in which the charge carriers are hydroxide ions rather than protons，have received a significant interest due to their potential for surpassing those limitations．AEMFCs operate under alkaline conditions，in which the electrode reaction kinetics will be enhanced and the catalysts are not subjected to corrosion．Furthermore，the fuel and water crossover via electro—osmotic drag may also be depressed because the transport of hydroxide ions and fuel are in the opposite directions．But nowadays，AEMs have two maior problems：low conductivity and low alkaline stability．Hence，it is essential to fabricate AEMs with high conductivity and good alkaline stability．Here，we designed and synthesized two kinds of AEM(crosslinked—type and side—chain-type)， and investigated the structure-property relationship of the membrane． First of all，a series of anion exchange membranes with high ionic-conductivity and low swelling ratio Was prepared from imidazolium—functionalized crosslinked cardo poly(arylene ether sulfone)s for AEMFCs．Two oligomers，tertiary amine—containing poly(arylene ether sulfone)(PES·DA)and bromomethyl-containing poly(arylene ether sulfone)(BPES)，are synthesized and then mixed at--40。C．They are spontaneously inter-crosslinked at room temperature to form dense anion exchange membranes(AEMs)，in which the quatemary ammonium groups of PES-DA rapidly react with the bromomethyl groups of BPES to form the crosslinked bonds．This avoids the use of