Investigation of poly(lactic acid) nanocapsules containing the plant extract via coaxial electrospraying method for functional nonwoven applications

Abstract

This study focuses on the development of functional nanocapsules via the coaxial electrohydrodynamic atomization (electrospraying) method. These nanocapsules can manipulate nonwoven surface functionality in terms of antibacterial characteristics for medical textile purposes. Electrosprayed nanocapsules were produced from Poly(lactic acid) (PLA) polymer and Plumbago europaea plant extract. Here, we employ optimized solution and process parameters (needle to collector distance, electrical field, application time, and needle dimension) for the coaxial electrospraying process. Different Plumbago europaea extract concentrations and co-fluids' flow rates were investigated as part of the study. Also, the effect of these parameters on capsule morphology and dimension were investigated. After the formation of PLA nanocapsules, morphological and dimensional characteristics were analyzed through SEM, FESEM, TEM images in addition to FTIR and nanosize measurements. According to our findings, a lower co-fluids' flow rate gives the smaller nanocapsules with narrow-sized distribution and desired spherical morphology. Antibacterial efficiency doesn't show any significant difference except the lowest plant extract concentrations. After characterizing the nanocapsules' structures, the core-sheath structure can be clearly identified. Consequently, the desired capsule morphology and size for nanocapsules were accomplished. The antibacterial efficiency of covered surfaces with nanocapsules is up to 80% for Staphylococcus aureus and about 31% for Escherichia coli, even with low pick-up ratios. Even for a very low amount of extract usage, good antibacterial efficiency can be achieved. The application has endless potential in terms of higher concentration and a wide range of chemical usage.