Formation and Properties of Electrospun Zein Nanofibers from Glacial Acetic Acid Solutions: Effects of Process Variables and Surfactants.

Electrospun zein nanofibers are promising bio-based materials, but producing uniform ultrafine fibers with desirable performance remains challenging. This study examined the effects of process variables and three surfactants on zein fiber formation, diameter, and material properties. Zein solutions (30-40%, w/v) were prepared in glacial acetic acid, and 2% (w/w, based on zein) triethyl benzyl ammonium chloride (TEBAC), sodium dodecyl sulfate (SDS), or span-80 was incorporated into the 30% zein solution. Zein concentration and feed rate yielded fiber diameters of 208.22-1001.90 nm. Surfactants reduced surface tension and increased conductivity, promoting jet stretching and generating uniform fibers with diameters near 100 nm. SDS produced the smallest fibers (98.92 ± 15.20 nm). TEBAC increased tensile strength from 11.08 to 63.26 MPa and improved dimensional retention in water, whereas SDS and span-80 increased elongation at break but reduced strength and stiffness. All surfactants increased wettability and altered intermolecular interactions and secondary structure of zein, although they reduced thermal stability. Overall, surfactants acted as both electrospinning aids and structure-directing modifiers, with TEBAC providing the best balance of fineness, strength, and aqueous stability. These ultrafine, robust, and water-stable nanofibers are promising as functional coating layers for high-moisture food packaging and as carriers for antioxidants or antimicrobial agents.