循环伏安法测定聚苯并咪唑膜电解质甲醇透过率

研究建立了电化学循环伏安法(CV)测定磷酸掺杂聚苯并咪唑(PBI)膜甲醇透过率的方法.以磷酸溶液为电解质,在扫描电压范围-0.2~1.2 V和扫描速度100 m V/s的条件下测试了不同磷酸掺杂水平PBI膜的甲醇透过率.研究表明,根据膜样品酸掺杂水平选择磷酸电解质溶液的浓度可使待测PBI膜的酸掺杂水平在测定过程中保持不变,进而保障结果的准确性和可靠性;与纯PBI膜的甲醇透过率(1.34×10-8cm2/s)相比,磷酸掺杂PBI膜的甲醇透过率有所增加,当PBI膜的酸掺杂水平为2.5~3.2时,膜的甲醇透过率为3.2×10-8~14×10-8cm2/s.

Measurement of the Methanol Permeability of Polybenzimidazole Membrane Electrolytes with Cyclic Voltammetry

A method for measuring the methanol permeability of phosphoric acid doped polybenzimidazole (PBI) membranes was developed by using cyclic voltammetry (CV). The methanol permeability of PA doped PBI membranes at different acid doping levels was investigated under a voltage range of -0.2~1.2V and at a potential sweep rate of 100mV/s using phosphoric acid solutions as electrolytes. The results indicated that using the PA solution with a suitable concentration as the electrolyte could maintain the acid doping level of the PBI membrane and ensure a precise and reliable result. Compared with that of the pure PBI membrane (1.34×10^-8cm²/s)， the methanol permeability of acid doped PBI membranes increased， i.e.， 3.2×10^-8~14×10^-8cm²/s， corresponding to the acid doping level of 2.5~3.2.