Liquid crystal-based multiple emulsion carriers for prolonged essential oil delivery: Toward functional antimicrobial...

Conventional fabric antimicrobial finishing agents (FAGs) suffer from short-term efficacy, textile damage, stain residue, and biosafety concerns. To address these issues, we developed a versatile eco-friendly FAG (CO-LCME) by fabricating liquid crystal-based multiple emulsion (LCME) carriers for sustained delivery of antimicrobial citronella oil (CO). The unique biomimetic architectures (pomegranate-like and matryoshka-like) of CO-LCME with ordered lamellar liquid crystal (L_α) phases were constructed via structure-directed emulsifier formulation engineering. Owing to the hierarchical confinement effect, CO-LCME achieved not only superior stability under complex environmental stresses (dilution, thermal storage, and freeze-thaw cycles), but also prolonged antimicrobial durability (>30 h) in fabric finishing applications. Furthermore, CO-LCME enabled uniform deposition on diverse textiles (e.g., cotton, silk, hemp, wool and leather) without residual staining and exhibited easy washability. Compared to commercial FAGs, CO-LCME demonstrated significantly lower effective concentration (10 mg/mL, containing 0.1 mg/mL CO) against S. aureus, E. coli, and C. albicans, alongside reduced cytotoxicity toward human keratinocytes (HaCaT) cells. This work provides a commercially viable and ecologically sustainable paradigm for innovative textile chemical finishing technologies.