| The research and development of membrane preparation is the key of membrane technology. In this work, two types of composite mem-branes have been prepared, which could be used in the vanadium redox flow battery and alkali recovery by diffusion dialysis and good results have been obtained. At the same time, the gas sensing properties of inor-ganic materials in the process of membrane preparation were tested.PES is a kind of polymer materials to form membrane easily, and it’s a good choice to fabricate membrane because of the stable chemical and physical properties, the resistance to acid and alkali and low cost. In this work, PES/Nafion porous composite membranes with tunable morpholo-gy were prepared via phase inversion method and were tested in the va-nadium battery. At first, PES porous membrane was prepared via intro-ducing PVP in PES cast solutions. Second, PES/Nafion porous composite membrane was prepared by coating with 5 wt % nafion solution. Last,these porous composite membranes were used in VFB. The results show that the performance of PES/Nafion composite membrane is better than PES membrane. For example, H/V selectivity of PES/Nafion membrane is 495.3 while PES membrane is 91.3.Further more, the EE of VFB as-sembled with PES/Nafion composite membrane is 88.6% while PES membrane is 80.3%. Therefore PES/Nafion porous composite membranes have promising use in VFB.Another type of hybrid membrane prepared in this thesis is SPPO/y-FeOOH ,which alkali resistance is better than pure SPPO mem-branes, and the separation factor of OH- and AlO2- is 11.3 in diffusion di-alysis.Another important discovery in this work is that sulfonated γ-Fe2O3 nanoflowers has potential application for acetone gas sensing. In this work, sulfonated γ-Fe2O3 nanoparticles has been fabricated via hydro-thermal method which the operation is simple and cost is low. The results indicated that the sensitivity of sulfonated γ-Fe2O3 is 9 times than y-Fe203 and it has no response to C2H5OH, CO and H2. Therefore, sulfonatedγ-Fe2O3 is a potential candidate for fabricating acetone gas sensor. |
