Process Optimization of Solution Blow Spinning for Poly ( N ‐Isopropylacrylamide) Fibers

ABSTRACT

Solution Blow Spinning (SBS) offers a safe, scalable, and versatile alternative to electrospinning for the fabrication of polymeric fibers. In this work, SBS was systematically investigated as a processing technique for the fabrication of continuous poly( N ‐isopropylacrylamide) (PNIPAM) fibers, a thermoresponsive polymer with significant potential for biomedical applications. A factorial and Box–Behnken experimental design was employed to evaluate the effect of polymer concentration, feed rate, air pressure, and working distance on fiber morphology. Rheological analyses indicated that increasing the polymer concentration enhanced chain entanglement, reduced the surface tension from 50.5 to 35.8 mN m ⁻¹ , and facilitated stable jet formation. Statistical analysis identified polymer concentration and feed rate as the dominant processing parameters, while air pressure and working distance exhibited secondary effects primarily through their interactions with the other variables. Reproducible production of homogeneous PNIPAM fibers with diameters below 2 μm was achieved within an optimized processing window of 16–17 wt.%, 2.5–3.2 mL/h feed rate, 21–23 psi air pressure, and 24–27 cm working distance. In contrast to previous SBS studies that primarily addressed conventional polymers, this work establishes a statistically optimized SBS processing framework for reproducible PNIPAM fiber fabrication, providing practical guidelines for future thermoresponsive fibrous systems.