Fabrication of High-Alignment-Degree Nanofiber Filaments Using Multi-Needle Electrospinning Equipment with an Auxiliary Electrode

High-alignment-degree nanofiber filaments were prepared using a multi-needle electrospinning device with an auxiliary electrode. The effects of the auxiliary electrode parameters on the alignment degrees (ADs) of the filaments were examined. The results showed the AD of the filament spun with a rounded rectangular auxiliary electrode (RAE) was better than that of that spun with a rectangular one (AE). Meanwhile, the ADs decreased with an increase in the size of the RAE, but they increased initially with increasing the height and voltage until 17.5 mm and 22 kV, respectively, and then decreased. Thus, the optimum auxiliary electrode parameters were an RAE shape, a size of 100 × 60 mm, a height of 17.5 mm, and a voltage of 22 kV. The structure, mechanical properties and productivity of the filament spun with the optimum RAE were studied. Compared with the filament spun without an auxiliary electrode, the nanofiber diameter of the filament spun with the RAE decreased by 9.9%, while the AD increased by 24.8%. The crystallinity increased, and the glass transition temperature and the melting temperature increased by 2.5 °C and 1.5 °C, respectively. The breaking stress and initial modulus increased by 33.3% and 18.3%, respectively, while the strain decreased by 12.5%. Meanwhile, the productivity increased by 14.8%.