Citrus waste oil and turmeric for antibacterial, mosquito-repellent cotton fabrics

This study introduces a sustainable approach for extracting essential oils from citrus peel residues using supercritical carbon dioxide (SC-CO₂) technology, addressing the resource wastage and environmental pollution associated with traditional disposal methods and the ecotoxicity of chemical textile auxiliaries. The experimental procedure was refined utilising response surface methodology based on Box-Behnken design. Under optimal conditions (solid-liquid ratio of 1:12 g/mL, extraction pressure of 20 MPa, and extraction time of 90.3 min), the yield of essential oil extraction reached 30.11 mg/g. Gas chromatography-mass spectrometry analysis confirmed that limonene was the predominant component, accounting for ≈51%. In addition, by harnessing the synergistic effect of citrus essential oil and turmeric dye, a mosquito-repellent emulsion derived from the extracted essential oil was applied to cotton fabrics via mordant dyeing. The cotton fabrics’ antibacterial and mosquito-repellent efficacy, ultraviolet protection, mechanical properties, breathability, and water washing resistance were evaluated pre- and post-finishing. The findings indicated that the antimicrobial efficacy of the cotton fabrics by post-treatment was 91.46%, the mosquito-repellent efficacy was 90.17%, and the tensile strength was increased by 33.3%.