Eco-engineered Opuntia cladode fibers: Environmentally benign extraction, structural, and functional properties

The increasing demand for environmentally responsible and biodegradable alternatives to synthetic materials has driven interest in plant-derived fibers for sustainable material development. This study focuses on the environmentally benign extraction and multifunctional characterization of fibers derived from Opuntia cladodes (OCF), emphasizing both the environmental merits of the process and the material's functional properties. The fibers were obtained using a water-based, chemical-free retting method conducted at ambient temperature, aligning with key principles of environmental chemistry by eliminating hazardous reagents, reducing energy consumption, and minimizing waste. Comprehensive analyses were performed to evaluate the structural, chemical, mechanical, and biological characteristics of the extracted fibers. Antibacterial assays showed substantial inhibition against Escherichia coli , with 100 μg of OCF producing a 24 mm zone of inhibition comparable to the standard antibiotic streptomycin (28 mm at 10 μg). Confocal laser scanning microscopy confirmed biofilm disruption through membrane damage and bacterial cell death. FTIR analysis revealed functional groups characteristic of cellulose, hemicellulose, and mucilage (–OH, –COOH, C–O–C), while XRD results indicated a largely amorphous structure (crystallinity index: 3.7%), suggesting enhanced biodegradability. The fibers exhibited a tensile strength of ∼11.3 MPa at 0.19 strain, and SEM imaging showed a stratified, uniform morphology suitable for reinforcement in composite application. This study demonstrates the sustainable potential of OCF by combining environmentally benign processing with functional performance.