Magnetic field‐induced alignment of polybenzimidazole microstructures to enhance proton conduction

Abstract

Aligned polymer microstructures in the field of biomaterials, semiconductors, and ion-conductive membranes expand steadily. Here, an alternative aligned polybenzimidazole (WM PBI) microstructures fabrication strategy based on the utilization of a weak magnetic field (0.3 T) via the solvent casting method is demonstrated. The anisotropic alignment is induced by the interaction of the π-electron-rich structure with the magnetic field. A ripple-like structure was observed in the field-emission scanning electron microscopy image for the WM PBI membrane, which depicted the successful alignment of the PBI structure toward magnetic field direction. Electrochemical studies revealed the bulk resistance of WM PBI with only 13.71 × 103 Ω compared to the unaligned PBI (WOM PBI) (63.01 × 103 Ω). WM PBI marked as the highest proton conductivity of 610.66 × 10−6 S cm−1, and it was proven that the external magnetic field does bring the impact toward the augmentation of the proton conductivity, which is useful in various future generation applications.