Preparation And Properties Of Hybrid Ion Exchange Membrane

Fuel cell is considered as one of the new clean energy technologies in the 21st century because of its high energy conversion efficiency and clean and pollution-free characteristics.Ion exchange membrane,including proton exchange membrane and anion exchange membrane,is the key component of fuel cell,which mainly plays the role of conducting ions and isolating fuel and oxidant.The ideal ion exchange membrane needs not only high ion conductivity,but also excellent stability(mechanical stability and chemical stability).Now,many methods of preparing high performance ion exchange membrane have been developed,including direct polymerization,radiation grafting,chemical modification,hybrid modification,etc.Among them,the hybrid modification is relatively simple and effective,and can give full play to the advantages of each component in the membrane to obtain the ion exchange membrane with excellent comprehensive performance.Therefore,the purpose of this thesis is to prepare high conductivity and high stability ion exchange membrane by hybrid method.The main work is as follows:(1)S-PS-b-PI block copolymer was synthesized by anionic polymerization,and sulfonated graphene oxide(SGO)was prepared at the same time.SGO@S-PS-b-PI ultra thin hybrid proton exchange membrane was prepared by vacuum suction filter layer self-assembly,using NMR,XPS,AFM,FIIR shows its chemical and physical structure.The thickness of the prepared ultrathin film can be as low as 1.76?m,with self-supporting ability,bending and folding,and certain toughness.In addition,the graphene hybrid membrane has high proton conductivity and water stability.The in plane proton conductivity of SGO@S-PS-b-PI_30%membrane is 61.53m S/cm@20?,which is about 55%higher than that of the pure SGO membrane(39.7m S/cm).It can not be dissolved in 80?water for 7 days,and still has excellent mechanical strength and thermal stability.(2)The surface cation loaded nano cellulose crystal(QCNC)was prepared,and the ultra-high content QCNC@QPVA hybrid AEMs was prepared with slightly quaternized polyvinyl alcohol(QPVA).Different from the traditional organic-inorganic hybrid ion exchange membrane,in this hybrid system,the ion conduction function comes from the quaternized nano filler QCNC,while the organic polymer QPVA mainly provides physical support and is basically non-ionic.The results show that the conductivity of70%QCNC@QPVA is the best,which is 10.22m S/cm at 20?,but the conductivity of hybrid membrane is low in general,but it has good alkali resistance.The conductivity loss of 70%QCNC@QPVA after 192 h is 16.88%at 80?and 6 M solution.