Memristive behaviour of PANI/Au hybrid nanocomposites synthesized via various routes†

Abstract

Herein, hybrid nanocomposite devices based on polyaniline (PANI) nanofibers decorated with gold nanoparticles (Au), as conductive fillers, and atactic polystyrene (aPS), as insulating matrix, were developed. To assess the effect of the PANI and Au synthesis procedure on the electrical behavior of the developed devices, PANI/Au nanosystems were synthesized via two different routes: (1) biphasic synthesis, wherein PANI nanofibers were grown through a biphasic synthesis procedure incorporating 1-dodecanthiol-capped Au (AuDT) nanoparticles, which were previously synthesized and dispersed in the reaction environment; (2) one-pot synthesis, wherein gold nanoparticles were directly reduced, starting with auric salt precursors on the PANI nanofiber surface, which were previously synthesized via a rapid mixing procedure. Thermal stability and the Au/PANI weight ratio were determined using thermogravimetric analysis (TGA). Furthermore, PANI/Au nanosystems were observed using transmission electron microscopy (TEM), revealing that the synthesis route significantly affected the morphology of nanosystems. Electrical characterization showed that aPS/PANI/Au hybrid nanocomposite devices exhibited a typical non-linear current–voltage curve with a closed hysteresis loop, which is a characteristic of memristive behavior. Moreover, devices made with fibers obtained via rapid mixing (PANI RM/Au) exhibited conductivities higher than those produced with fibers from biphasic synthesis (PANI BF/AuDT).