Different types of ABPBI (poly(2,5-benzimidazole)) membranes and polymer binders were evaluated to investigate the performance of MEAs for high temperature proton exchange membrane fuel cell (HT-PEMFC). The properties...Different types of ABPBI (poly(2,5-benzimidazole)) membranes and polymer binders were evaluated to investigate the performance of MEAs for high temperature proton exchange membrane fuel cell (HT-PEMFC). The properties of the prepared MEAs were evaluated and analyzed by polarization curve, electrochemistry impedance spectroscopy (EIS), cyclic voltammetry (CV) and durability test. The results showed that MEA with modified ABPBI membrane (AM) has satisfactory performance and durability for fuel cell application. Compare to conventional PBI or Nafion binders, polytetrafluoroethylene (PTFE) and polyvinylidene difluoride (PVDF) are more attractive as binders in the catalyst layer (CL) of gas diffusion electrode (GDE) for HT-PEMFC.展开更多
The zwitterionic compound,levofloxacin,was determined for the first time at different pH values in pure samples,pharmaceutical preparations and spiked serum and urine samples.Different types of potentiometric sensors ...The zwitterionic compound,levofloxacin,was determined for the first time at different pH values in pure samples,pharmaceutical preparations and spiked serum and urine samples.Different types of potentiometric sensors including poly(vinyl chloride)membrane electrode,carbon paste electrode and screen printed electrode,containing the ion pair levofloxaciniumphosphomolybdate as the electroactaive species,were used for this purpose.The effect of pH is the key factor in determining the ratio of the different species that can exist in the medium(zwitterionic,monocationic,dicationic,anionic and neutral),and so it is the controller of the electrochemical performance.The different sensors were fully characterized and optimized in terms of composition,pH effect,selectivity,response and lifetimes.The different sensors showed reliable reversibility and could be utilized for the determination of the drug in real spiked physiological fluids with reliable recovery values.展开更多
文摘Different types of ABPBI (poly(2,5-benzimidazole)) membranes and polymer binders were evaluated to investigate the performance of MEAs for high temperature proton exchange membrane fuel cell (HT-PEMFC). The properties of the prepared MEAs were evaluated and analyzed by polarization curve, electrochemistry impedance spectroscopy (EIS), cyclic voltammetry (CV) and durability test. The results showed that MEA with modified ABPBI membrane (AM) has satisfactory performance and durability for fuel cell application. Compare to conventional PBI or Nafion binders, polytetrafluoroethylene (PTFE) and polyvinylidene difluoride (PVDF) are more attractive as binders in the catalyst layer (CL) of gas diffusion electrode (GDE) for HT-PEMFC.
文摘以磺化度为75%的磺化聚醚醚酮(SPEEK)为原料,加入聚醚酰亚胺(PEI)和离子液体(ILs)制备SPEEK/PEI@ILs酸碱复合膜用于质子交换膜电解水制氢(PEMWE)中.研究复合膜的吸水率、溶胀度、质子电导率、热稳定性和相应的PEMWE性能.结果表明,SPEEK/PEI@ILs复合膜与商业Nafion117膜相比,具有相近的质子电导率和溶胀度,说明PEI的加入,增强了复合膜的尺寸稳定性.将SPEEK/PEI@ILs复合膜制备成膜电极并测试PEMWE性能,1 A/cm2电流密度下槽电压为2.75 V,在0.5 A/cm^(2)@1.96(±0.03)V条件下能稳定运行10 h.
文摘The zwitterionic compound,levofloxacin,was determined for the first time at different pH values in pure samples,pharmaceutical preparations and spiked serum and urine samples.Different types of potentiometric sensors including poly(vinyl chloride)membrane electrode,carbon paste electrode and screen printed electrode,containing the ion pair levofloxaciniumphosphomolybdate as the electroactaive species,were used for this purpose.The effect of pH is the key factor in determining the ratio of the different species that can exist in the medium(zwitterionic,monocationic,dicationic,anionic and neutral),and so it is the controller of the electrochemical performance.The different sensors were fully characterized and optimized in terms of composition,pH effect,selectivity,response and lifetimes.The different sensors showed reliable reversibility and could be utilized for the determination of the drug in real spiked physiological fluids with reliable recovery values.
