Electric field simulation of multi-needle water bath electrospinning and the structural properties of SCN/PAN micro/nanofiber composite yarns

Abstract

Multi-needle water bath electrospinning is one of the most efficient methods to prepare micro-nano fiber composite yarns. The nanofiber structure can be targeted regulated to obtain high performance composite yarns. In order to explore the effect of receiving distance on the structure and properties of micro-nano fiber composite yarns, polyacrylonitrile nanofibers were uniformly coated on silver-coated nylon yarn by four-needle continuous water bath electrospinning method. The electric field distribution at different receiving distances was simulated by ANSYS finite element analysis software, and the effect of electric field distribution on the structure and properties of micro-nano fiber composite yarns were studied. The results indicated that the peak electric field intensity appeared at the tip of the needles and decreased with the increase of receiving distance. The receiving distance was constant, the field intensity was lower when the direction of the centerline of the needle tip was farther away from the tip, but the field intensity at the conductive core yarn was higher than that in the surrounding area (small spikes). The average field intensity of small spikes at 180 mm was only 1/4 of that at 80 mm. When the receiving distance increased within a certain range (100~140 mm), the nanofibers had smooth surface and good separation, nanofibers diameter decreased continuously, and the porosity changed inversely. With the further increase of the receiving distance, the nanofibers gradually bonded, the nanofibers diameter increased, and the porosity changed oppositely. The coating rate of nanofibers showed a decreasing trend, and the mechanical properties of micro-nano composite yarns were improved. When the receiving distance was 100 mm, the porosity reached 38.94%, the breaking force, breaking elongation and breaking strength were 13.71±1.36 cN, 22.76±6.62% and 0.15±0.02 cN·dtex-1, respectively. Considering all factors, the receiving distance of 100 mm is appropriate.