*2.1. Solutions Preparation*

Prior to the solution's preparation, polymers were dried in an oven (SLN32STD, POL-EKO-APARATURA sp.j., Wodzisław Sl ˛ ´ aski, Poland) for 3 h at T = 30 ◦C. PS (Sigma Aldrich, Gillingham, UK, Mw = 350,000 g·mol−1) was dissolved in dimethylformamide (DMF, 99.8%, POCH, Gliwice, Poland) at a concentration of 25 wt%, PA6 (BASF, Ludwigshafen, Germany, Mw <sup>=</sup> 24,000 g·mol<sup>−</sup>1) was dissolved in formic acid (85%, POCH, Gliwice, Poland), and acetic acids (99.5%, POCH, Gliwice, Poland) mixed in a volume ratio of 1:1 at 12 wt%. Both solutions were stirred at 500 rpm for 4 h at 20 ◦C (IKA RCT basic, Staufen, Germany). The concentration of the polymer solution was adjusted according to the molecular weight of the polymer to obtain suitable viscosity, allowing it to produce beadles' fibers.
