Electrospun Nanofiber Enhanced Sulfonated Poly(arylene ether nitriles)-based Proton Conducting Membrane

To study the effect of electrospun nanofiber on proton conductivity of sulfonated poly(arylene ether nitriles) (SPEN), the nanofiber mats were prepared by the electrospinning technology and the nanofiber/SPEN proton conducting membranes with different SHQ content were fabricated via impregnation method. For comparison, the casting SPEN membrane was also prepared by the solution-casting method. The scanning electron microscope (SEM) was used to observe the morphologies of electrospinning nanofiber mats. The water uptake, thermal and oxidative stability of casting SPEN and the nanofiber/SPEN membranes were also detailed studied. Besides, the nanofiber/SPEN membranes possess the higher proton conductivity than that of casting SPEN. The SPEN composite membrane with 5 wt% SHQ nanofiber exhibits the highest proton conductivity of 0.044 S/cm and 0.0865 S/cm at 20 degrees C and 80 degrees C, respectively. However, after second times water treatment, the conductivities of nanofiber/SPEN membranes are all lower than that of original value due to the shift loss of dissociative sulfonic acid group. Therefore, although the electrospinning is a good method to improve proton conductivity, it is also a great challenge to avoid the shift loss of sulfonic acid group for the nanofiber/SPEN.