Fabrication Of Polysulfone/Functionalized Fillers Hybrid Membranes And Intensification Of Anion Conduction Property

As the new generation of ion exchange membrane fuel cells,anion exchange membrane fuel cells?AEMFCs?possess several advantages over proton exchange membrane fuel cells?PEMFCs?,such as potential use of non-noble metal as electrocatalysts,lower fuel permeability and better oxygen-reduction reaction kinetics.AEMFCs are receiving more and more attentions in the past decade.The anion exchange membrane is one of core and performance-determined components for AEMFCs.In this study,basic imidazolium-functionalized graphene oxide,polymeric submicrospheres bearing quaternized polystyrene brushes,and polymeric submicrospheres bearing chloromethylated polystyrene brushes are designed and fabricated,and then incorporated into polysulfone matrix to prepare hybrid membranes.By increasing the number of ion transport sites,optimizing the water uptake and swelling properties and constructing the efficient continuous ion transport channels,anion transfer characteristics of membranes are intensified.1.Basic imidazolium-functionalized graphene oxide?ImGO?was designed and fabricated,and then incorporated into basic imidazolium-functionalized polysulfone?ImPSU?matrix to prepare a series of ImPSU/ImGO hybrid membranes.The large amount of imidazolium ionic groups improved ion exchange capacity of the hybrid membranes,promoting the efficiency of the anion transport in the membranes.As one of two-dimensional materials,ImGO possesses continuously spatial structure and help to construct efficient continuous ion transport channels in the membrane,which further strengthen the anion transfer through the membrane.For ImPSU/Im GO-0.2 hybrid membrane,the hydroxide conductivity reached 22.02 mS cm^-1 at room temperature and 100% RH,which was 110% higher than that of pristine ImPSU membrane.The residual hydroxide conductivity ratios of ImPSU/ImGO-0.2 hybrid membrane were nearly 8-fold higher than that of pristine ImPSU membrane after treating by hot aqueous alkali for 48 h.2.Polymeric submicrospheres bearing quaternized polystyrene brushes?QABNPs?were designed and synthesized,and then incorporated into basic imidazoliumfunctionalized polysulfone?ImPSU?matrix to prepare a series of ImPSU/QABNPs hybrid membranes.Quaternized polystyrene chains grafted on the surface of QABNPs extended into the ImPSU matrix,forming strong hydrophilic interaction between QABNPs and ImPSU.The interaction helped to not only create efficient and orderly anion transfer channels,but also inhibit the swelling under high temperature for hybrid membranes.ImPSU /QABNP-5 hybrid membrane showed only 19.62 swelling ratio at 60 oC,22% lower than that of the pristine ImPSU membrane.ImPSU/QABNP-1.0 hybrid membrane exhibited the ptimized hydroxide conductivity with 38.33 mS cm^-1 at room temperature and 100% RH,about 167% higher than that of the pristine ImPSU membrane.3.polymeric submicrospheres bearing chloromethylated polystyrene brushes?CMBNPs?were designed and synthesized,and then incorporated into polysulfone?PSU?matrix to prepare a series of crosslinked PSU/QABNPs hybrid membranes.The large amount of imidazolium ionic groups increased the number of ion transfer sites and endowed hybrid membranes good hydrophilicity.Simultaneously,crosslinks between the polymer chains can well suppress the swelling effectively under high water content and connect hydrophilic regions together to construct efficient anion transport channels,giving hybrid membranes excellent anion conductivity.Crosslinked PSU/QABNP-70 hybrid membrane showed a high water uptake of 108.82% and a low swelling ratio of 15.49%,with a high chloridion conductivity of 62.70 mS cm^-1 at 80 oC and 100% RH.