Fabrication And Study Of Anion Hybrid Membranes Containing Functional Particles With Ionic Liquids

To overcome the shortage of global energy,fuel cells have become the focus of energy research due to their high efficiency and non-pollution.It is important to prepare a high performance ion exchange membrane which is the core part of a fuel cell and can affect the performance of cells.In this study,we have prepared functional particles by imidazolium-based ionic liquids and synthesized hybrid membranes with functional particles and polymer.The imidazolium-based ionic liquid increases the number of anion-conducting groups in the membranes,and the functionalized particles optimize the anion-conducting channels in the membranes,which improves the performances of the anion exchange membranes.This research mainly carried out as follows:（1）A new imidazolium-based ionic liquid named 1-nitrileethyl-2-methyl-3-（3-aminopropyl）imidazole bromide was synthesized in order to modify imidazole ionic liquid on graphene oxide.The imidazolium-based ionic liquid-functionalized graphene oxide（IL-GO）was prepared,and Im PPO/IL-GO nanohybrid membranes with different contents were prepared.The incorporation of IL-GO improves the ion conductivity of the anion exchange membranes and enhances the stability of the membranes.At 20℃,the anion conductivity of Im PPO/IL-GO-3 was 0.032 S·cm^-1,which was 113%higher than that of Im PPO.And both the water absorption and swelling degree of the anion exchange membranes were reduced,which enhanced the stability of the membranes.（2）1-n-butyl-3-vinylimidazole bis（trifluoromethanesulfonimide）salt was designed and synthesized,and the imidazole poly（ionic liquid）porous microspheres named P（St-co-BVBS）were prepared.And it was incorporated into the membranes to prepare Im PPO/P（St-co-BVBS）membranes with different contents.P（St-co-BVBS）provided more transfer sites for the membranes.At 20℃,the anion conductivity of Im PPO/P（St-co-BVBS）-8 is 0.035 S·cm^-1,which is 150%higher than that of Im PPO.The alkali stability of anion nanohybrid membranes was also improved.Under alkaline conditions,the anion conductivity of Im PPO/P（St-co-BVBS）-6 could be stabilized at 69%.（3）Four imidazolium-based ionic liquids with different groups were synthesized,which were 1-ethyl-2-methyl-3-（3-aminopropyl）imidazole bromide（[EMAIm]Br）,1-n-butyl-2-methyl-3-（3-aminopropyl）imidazolebromide（[BMAIm]Br）,1-isobutyl-2-methyl-3-（3-aminopropyl）imidazole bromide（[IMAIm]Br）and1-phenyl-2-methyl-3-（3-aminopropyl）imidazole bromide（[Ph MAIm]Br）.The graphene oxide with imidazolium-based ionic liquids was prepared by chemical methods.A series of anionic hybrid membranes were prepared by the blending method,and the stability of the membranes were explored with theoretical calculations.The results showed that the LUMO energy and the OH^-binding energy of the IMAIm were the lowest,which were-0.980 e V and-0.509 e V.The results of alkali stability measured in the experiment were as follows:M-IMAIm>M-BMAIm>M-EMAIm>M-Ph MAIm,which are consistent with the results of theoretical calculation.It is proved that the degradation of the imidazole can be inhibited by designing the groups in imidazolium-based ionic liquids and the alkali stability of the anion exchange membranes also increases.