Preparation of vertically aligned carbon nanotube/polyaniline composite membranes and the flash welding effect on their supercapacitor properties

A vertically aligned carbon nanotube (CNT)/polyaniline (PANi) composite membrane was prepared by a simple filtration and electrical synergy method. Considering the high alternating electric field and strong shear forces during suction, vertically aligned single-walled nanotubes (SWNTs) were found in the SWNT/PANi composite membrane. Scanning electron microscopy and polarised Raman scattering demonstrated that the degree of alignment of the SWNTs improved with increasing electric voltage. Nanoindentation technology indicated that the modulus and hardness of the SWNT/PANi composite membrane increased in the vertically aligned CNTs. Owing to the special photo-thermal property of the PANi nanofibres, a SWNT/PANi composite film with an improved crosslinking structure and strong π–π interactions between PANi and SWNTs was obtained by intensity flash irradiation. The surface density, water contact angle and thermal stability of the composite film increased after flash welding. Nanoindentation technology indicated that the SWNT/PANi composite film significantly increased in modulus and hardness after flash welding. The SWNT/PANi film fabricated by filtration and electrical synergy method also demonstrated an improved specific capacitance of 146.0 F g−1 in 6 M KOH at 0.5 A g−1 after flash welding while maintaining good cycling stability. The prepared SWNT/PANi composite film is suitable for portable and wearable electronic applications.