Development of Antimicrobial Textile Coatings Through Encapsulation of ZnO in Electrospun PLA Fibers

The present study investigates the development of antimicrobial textile coatings by encapsulating zinc oxide (ZnO) particles within electrospun polylactic acid (PLA) fibers. Electrospinning was used to produce uniform fibrous coatings with effective incorporation of ZnO. ZnO reduced solution viscosity and increased conductivity, resulting in thinner and more homogeneous fibers. Thermogravimetric analysis confirmed high encapsulation efficiency (up to 95%) and a significant loading capacity (47.71 ± 1 mg ZnO/g fiber), while scanning electron microscopy revealed uniform fiber structures with high-contrast regions that are qualitatively consistent with the presence of ZnO-rich domains. The release behavior of ZnO was assessed under simulated washing and perspiration conditions. Results showed limited release under sweat conditions (R < 0.07), indicating strong ZnO retention under perspiration-related exposure, whereas washing increased release from the free-standing coatings (up to 0.32), indicating partial ZnO retention under more aggressive aqueous surfactant conditions. Kinetic modeling using first-order, Higuchi, and Korsmeyer–Peppas models indicated that ZnO release was predominantly diffusion-controlled, with the Higuchi and Korsmeyer–Peppas models showing the best fit to the experimental data. Following thermal bonding onto textile substrates, the coatings achieved successful macroscopic integration; however, washing simulation of the bonded coatings resulted in more pronounced ZnO loss, while sweat exposure caused only limited release. The antimicrobial activity of the coatings was assessed against Staphylococcus aureus and Klebsiella pneumoniae (ISO 20743:2021). The PLA/ZnO (5% w/v) system showed strong broad-spectrum antibacterial activity, with values of 4.71 and 3.37, respectively. Overall, electrospun PLA/ZnO coatings show potential as antimicrobial textile coatings, offering controlled release behavior, strong antibacterial activity, and condition-dependent ZnO retention.