Ozone Treatment Preparation Of Modified Hydrophilic PVDF Ion Exchange Membrane

Microbial fuel cell(MFC), a new generation of power generation equipment, use of microbial oxidation and decomposition of organic compounds at the same time produce electrical current, has the advantages of green environmental protection and realize energy recycling, is one of the important research topics of researchers. Ion exchange membrane as a major part of the MFC system, plays an important role in proton conductivity, its performance will directly affect the overall performance level of MFC. O ne of the most used in the present study is Nafion perfluorinated sulfonic acid series of ion exchange membrane, the membrane has higher proton conductivity, stable performance, but its technology is complex, high cost, to some extent limits its development. In this study, polyvinylidene fluoride(PVDF) by modifying, prepared ion exchange membrane, and applied to the MFC, and N117 membrane performance comparison.In this paper, by using the strong oxidation of ozone to dissolve in Nmethyl-2-pyrrolidone(NMP) solution of PVDF pretreated to generate active molecular chain peroxide groups, then the initiator is added benzoyl peroxide(BPO) and dissolved in dimethyl sulfoxide(DMSO) at a styrene sulfonate(SSS) solution, a method by heat- initiated graft polymer is prepared(PVDF- g-SSS), solvent evaporation and finally after preparation of modified PVDF membrane(PS film). By using infrared spectroscopy(FT-IR), scanning electron microscopy(SEM), X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) to characterize the grafting of PVDF before and after, FT-IR analysis showed that at 1668cm-1 appears the-C = Ccharacteristic absorption peaks, at 1009cm-1 appears the sulfonic acid group characteristic absorption peaks; the SEM observed that the surface of the grafted membrane pore size becomes small, the density increases, the structure is more uniform and compact; XRD analysis showed that the graft around the PVDF crystalline form has not changed, but the crystal structure transformed from order to disorder; XPS analysis showed that grafted membrane surface increases the element of S and O; above analysis directly or indirectly showed that SSS had successfully grafted onto the PVDF molecular chain. This paper also examined the SSS monomer amount of PS membrane ion exchange capacity(IEC), the impact graft, conductivity, surface contact angle, moisture content, swelling ratio and mechanical strength properties and comprehensive consideration of all aspects, finally confirmed that when the ratio of PVDF / SSS is 1/5, PS membrane performance is optimal, and this time the IEC is 2.5 mmol / g, electrical conductivity is 0.046 s / cm.This topic placed homemade PS membrane and N117 membrane respectively in two MFCs device which have the same conditions at same time, by testing the system output power density, polarization curves, COD removal efficiency and coulombic efficiency(CE) indirectly reflect two kinds the basic difference in performance ion exchange membrane, the results showed that the PS membrane MFC system resistance and COD removal efficiency is higher than the N117 membrane systems, power density and C E value than the slightly lower, but due to the low cost of PS film, it still has use value.