Electro-spun poly(lactic acid)/poly(triarylamine) composite nanofibers: Making a biocompatible polymer electroactive

Composite poly(lactic acid)-(PLA)/poly(triarylamine)-(PTAA) nanofibers were fabricated via electrospinning for the first time. The objective was to make PLA electroactive via the addition of a p-doped conducting polymer (PTAA). Using CHCl₃ as the common solvent, several composite solutions of PLA and PTAA were prepared. No phase separation or polymer precipitation was observed in the composite solutions prior to electrospinning. At 1wt% and 3wt% PTAA concentrations, the electro-spun fibers were short, and a large amount of polymer beads filled the target substrate. Above 5wt% the fibers were long and uniform with no bead formation. The fiber diameters increased with increasing PTAA concentration. UV/Vis spectra of the blend solutions show a characteristic peak at 390nm and was similar to the spectra of pure PTAA. Using nanofibers electro-spun from the 5wt% solution we fabricated a p-n diode with a turn-on voltage of 0.63V, and an on/off ratio of 800. In addition, the diode was successfully used to rectify a low frequency ac signal with a rectifier efficiency of 15%. Electrospinning is therefore presented as a facile technique of fabricating electroactive polymer nanofibers that are biocompatible and can be used in devices and sensors.