Ultrathin and nanofibers via room temperature electrospinning from trifiuoroacetic acid solutions of untreated lignocellulosic sisal fiber or sisal pulp

Lignocellulosic sisal fiber (LSF) and sisal pulp (SP) were electrospun at room temperature from solutions in trifluoroacetic acid (TFA) prepared at concentrations of 2 x 10(-2) g mL(-1) and 3 x 10(-2) g mL(-1) respectively. Scanning electron microscopy images of the electrospun LSF showed fibers with diameters ranging from 120 to 510 nm. The presence of defects decreased along with increasing the flow rate of the SP solution, which generated nanofibers and ultrathin fibers with diameters in the range of 40-60 (at 5.5 mu L min(-1)) up to 90-200 nm (at 65.5 mu L min(-1)). Despite the known ability of TFA to esterify the hydroxyl groups present in the starting materials, the Fourier transform infrared spectra indicated the absence of trifluoroacetyl groups in the electrospun samples. The thermal stability of the final materials proved suitable for many applications even though some differences were observed relative to the starting materials. This study demonstrated a feasible novel approach for producing nano/ultrathin fibers from lignocellulosic biomass or its main component, which allows for a wide range of applications for these materials. (C) 2015 Wiley Periodicals, Inc. (AU)