In recent years, the technique of electrospinning has been used to develop a novel class of micro-and nanoscale materials based on fibrous structures. Several polymers, in particular elastomers, that have been implemented in this process rely on properties such as elasticity, flexibility, biocompatibility, and low cost. Herein, we describe for the first time the electrospinning of natural rubber fibers without polymeric matrix to obtain self-standing non-woven mats and oriented elastomeric fibers. The fibers average diameters were approximately 5.5 µm. Polyaniline (PAni) was deposited on the membrane surface in order to enhance the conductive properties making easy the charge transportation. We have obtained biocompatible and flexible fibrous materials using natural rubber, this research opens up possibilities of using micro and nanofibers of only-natural rubber in many applications including sensors preparation.

With the advancement of nanotechnology, nanomaterials such as nanofibers have gained attention, as they have applications in technological, environmental and health areas. In this context, electrospinning stands out for being considered a simple and versatile technique that allows the production of nanofibers. Carbon-based additives have been used to compose the polymeric matrix responsible for obtaining nanofibers, such as graphene, which among its applications has been used in gas sensors, as it can detect some molecules, including the ammonia. Thus, it is interesting to carry out studies of the polymer poly(vinyl alcohol) (PVA), together with the additive reduced graphene oxide (rGO), aiming at the application in ammonia gas sensor. Thus, electrospun PVA nanofibers with rGO were produced at different concentrations. To analyze the influence of rGO on PVA nanofibers, they were characterized by optical microscopy (OM) and tested in the presence of ammonia gas, generating graphs of current (i) by time (t). Therefore, electrospun nanofibers with considerable quantity and good formats were obtained, as seen in the OM images. By the graphs of i vs t, it was observed that the nanofibers that contained 4% of rGO showed greater sensitivity in the presence of ammonia gas, proving that rGO can be used as an additive in polymeric nanofibers with application in ammonia gas sensor.