Sustainable Bilayer Nanoemulsions for Textiles with Enhanced Thermal Stability for Prolonged Release

This study explores the development of a natural polymer-based nanoemulsion (AG–CN@NE) for encapsulating citronella essential oil (CEO) in textiles, targeting thermal stability, controlled release, and multifunctionality. A sustainable formulation using almond gum and chitosan was optimized for personal care, home care, and laundry applications. The ideal oil-to-surfactant ratio was 10–12.5%. Among various formulations, the AG/CN 3:1 ratio yielded the most stable emulsion with a droplet size of 72.86 nm and a PDI of 0.258. FTIR spectroscopy confirmed CEO encapsulation. TGA revealed enhanced thermal stability with CEO evaporation. The emulsion remained stable for 30 days at room temperature and 4 °C and retained fragrance despite mild turbidity at 60 °C. Microscopy confirmed uniform nanoemulsion adherence on cotton, and postwash studies showed an intact coating even after ten washes. After five wash cycles, 73.25% of CEO was retained, reflecting the strong durability and aroma retention. Additionally, AG–CN@NE/1 exhibited controlled and prolonged CEO release, with 25.83% of the oil content remaining after 14 days, supporting long-lasting fragrance delivery. These results demonstrate AG–CN@NE’s potential as a sustainable platform for fragrance delivery in functional textiles, green detergents, and eco-conscious personal and home care products.