3. Results and discussion
3.1. SEM analysis
It is seen from the SEM images (Fig. 1) that the PANI films had uniform nanofibrous morphology with diameters around 80–120 nm and length upto several micrometers, thus having high aspect ratios, characteristic of nanofibrous structures. Nano rods, on the other hand are significantly shorter, straighter and not branched. The nano fiber synthesized by the employed technique exhibit three-dimensional flexible, branched [49] interconnected
networking [50] with highly porous surface and large surface area. The porous surface of the film ensured easy and fast diffusion of gas inside the polymer matrix, thus causing a short response time. The smaller diameters of the fibers made way for rapid diffusion of dopants onto the polymer surface. Each of the nanofibers presented a three-dimensional structural surface which allowed better adsorption of gas or dopant in comparison to flat 2-dimensional
film [14,29].