Effects of Various Surfactants on Alkali Lignin Electrospinning Ability and Spun Fibers

Anionic, cationic, and nonionic surfactants with varying concentrations (0.2-4.2%) were introduced to neutralize beads on lignin nanofibers by decreasing the surface tension of spinning dopes. The surfactants used in this work were sodium dodecyl sulfate (SDS), N,N,N-trimethyl-1-dodecanaminium bromide (DTAB), and Triton X-100 (TX-100). The effects of viscosity, rheological properties, surface tension, and conductivity of the solutions on the morphology and physicochemical performances of fibers were investigated. As expected, the presence of certain amounts of surfactants eliminated the beads and resulted in the formation of smooth and bead-free fibers with small diameters. Furthermore, the gravimetric capacitance of the carbon mat with 1% SDS was slightly improved from 66.3 to 80.7 F g(-1). The results suggested that the surfactants benefit from the electrospinning of lignin and allow for the control over nanofiber morphology without compromising their performance as supercapacitor electrodes.