Preparation Of MOFs Derived Carbon/sPPO Nanocomposite Membrane And Application In Salinity Gradient Energy Extraction

Energy plays a very important role in social and economic development.Salinity gradient energy is a clean renewable energy source from the ocean.At present,there are many technologies applied in salt difference energy conversion,among which reverse electrodialysis(RED)is one of them.As the core component of RED system,ion exchange membranes(IEMs)play an important role in salt extraction.As a new type of ion exchange membrane,organic-inorganic nanocomposite membrane combines the advantages of organic membrane and inorganic nanoparticles,which can effectively improve the energy productivity of RED system.In this study,metal organic framework(MOF)-derived nanoporous carbons(hollow zeolitic imidazolate framework(ZIF)-derived nanoporous carbons,HZCs)was incorporated in a sulfonated poly(2,6-dimethyl-1,4-phenylene oxide)(s PPO)membrane to prepare an organic-inorganic nanocomposite cation exchange membrane(CEM).Morphologies,mechanical and thermal properties of the synthesized HZCs/s PPO nanocomposite membranes were characterize.Results showed that the thickness of the nanocomposite membrane was about 20μm,and the structure of the membranes were compact without obvious gaps.With the increase of HZCs loading,the surface and the microstructure of the membranes became more and more rough.The thermal properties of the membrane before and after loading HZCs had no obviouse change while the tensile strength(TS)and the elongation at break(Eb)were significantly various with the increase of the loading of nanoparticles.The results of the electrochemical performance experiments showed that addition of HZCs could improve the physical and chemical properties of HZCs/s PPO nanocomposite membrane as well as the power generation of RED stacks.When the HZCs loading was 1.0wt.%,the highest permselectivity was 77.61%,and the lowest surface resistance was 0.42Ω·cm~2.The total power density of the nanocomposite membrane in RED system was 0.45W/m~2 which was 87.5%(1.87 times)higher than that of the blank s PPO membrane.In this study,the operating condition was also investigaged as it is one of the main factors affecting the power generation performance of RED system.In the self-assembling RED system HZCs/s PPO membranes with HZCs loading of 1.0 wt.%were selected as the cation membranes,and commercial anion exchange membranes(AEMs)were used as the anion membranes.The results showed that,with the increase of the feed liquid cycle time,the power generation density of RED system.The higher feed velocity could produce a higher the power generation.The reverse electrodialysis power generation density was the highest when feeding from the bottom to the top,but it became the lowest when feeding from the top to the bottom.The increase of the concentration difference between concentrated solution and dilute solution resulted in an increase of the power generation density of RED.In this thesis,there are 21 figures,7 tables and 105 references.