Preparation Of PVDF-g-PSSA/SiO₂-SO₃H Composite Proton Exchange Membrane And Its Application In Microbial Fuel Cell

In recent years,microbial fuel cell?MFC?has attracted much attention.Searching for a clean,highly effective and anti pollution microbial fuel cell proton exchange membrane is a research hotspot.The sulfonated SiO₂ nanoparticles were prepared and mixed with PVDF-g-PSSA homopolymers of different quantities of SiO₂-SO₃H particles,and the properties of the SiO₂-SO₃H composite membranes,SiO₂composite film,PVDF-g-PSSA membrane and the hydrophilic property and proton conductivity were compared,and the optimum membrane was optimized.The structure,surface morphology and crystal structure of SiO₂-SO₃H composite membrane,SiO₂ composite film and PVDF-g-PSSA film were characterized by FT-IR,SEM and XRD;The adsorption behavior of three kinds of membranes to protein in ultra pure water and 50mMPBS solution was investigated by QCM-D,and the surface ZETA potential of BSA and membrane in two kinds of solutions was measured to find out the antipollution properties of the membrane.Finally,the optimized SiO₂-SO₃H composite membrane,SiO₂ composite membrane and PVDF-g-PSSA film were placed in MFC system respectively,and their comprehensive performance was observed after the system was stable.Finally,the following conclusions are drawn.?1?.The hydrophilic properties,proton conductivity and mechanical properties of the SiO₂-SO₃H composite membranes are better than that of Si O₂ composite membrane and PVDF-g-PSSA memrbane compared with the SiO₂-SO₃H composite membrane,SiO₂ composite membrane and PVDF-g-PSSA membrane.As the addition of SiO₂-SO₃H particles increases,the composite performance of the composite membrane increases continuously,when SiO₂-SO₃H particles are added.?2?.The surface of the different membranes was tested by FT-IR and XRD,and the infrared spectra were similar,but the SiO₂/SiO₂-SO₃H composite membrane could?3?clearly show the existence of the Si-O-Si functional group.The addition of SiO₂-SO₃H has little effect on the crystal form of PVDF,but the proportion of amorphous component increases and the crystallinity decreases,which is more favorable for the proton conduction in the membrane.The SiO₂-SO₃H composite membrane,SiO₂ composite membrane and PVDF-g-PSSA membrane were characterized by SEM.Compared with the PVDF-g-PSSA membrane,the pore density of the composite membrane is obviously larger and the pore dispersion is more uniform after adding the sulfonated SiO₂,which is more beneficial to the improvement of mechanical properties of the membrane and the conduction of the proton.?4?.The ZETA potential test showed that the 5%SiO₂-SO₃H composite membrane had lower electronegativity,which could enhance the membrane resistance to protein contamination.The QCM-D experiment showed that the quality of the adsorbed protein on the surface of the composite membrane with 5%SiO₂-SO₃H particles was significantly lower than that of the PVDF-g-PSSA membrane,and the adsorption layer was loose and easy to clean,and the anti pollution performance was better.In 50mM PBS solution,the amount of protein adsorbed on the membrane surface is larger than that in the ultra pure water,the fouling on the membrane surface is more serious,and the structure of the pollutant layer is loose.?5?.The polarization curves of the MFC devices composed of three kinds of membranes were compared,and the internal resistance of the MFC device composed of SiO₂-SO₃H composite membranes was less than that of the SiO₂ composite membrane and the PVDF-g-PSSA membrane device.Because of the increase of the number of sulfonic groups on the surface of SiO₂-SO₃H composite membrane,the increase of water content and proton conductivity makes the membrane internal resistance decrease.The power density curves of the three membranes also show that the SiO₂-SO₃H composite membrane MFC device has a higher maximum power density.?6?.The MFC devices composed of three kinds of membranes have better COD removal efficiency,in which the COD removal rate of the MFC device composed of SiO₂-SO₃H composite membrane is slightly higher than that of the other two membranes,and the CE value of the three kinds of membranes is not large,and the CE value of the MFC device consisting of SiO₂-SO₃H composite membrane is the largest.