Fabrication of tannic acid-functionalized sugarcane fiber reinforced chitosan based biocomposite sheet: A sustainable antibacterial solution for shoe insoles

Abstract

Chitosan is often blended with other materials to form composites to improve its limited antimicrobial activity and weak mechanical strength properties. In the present investigation, cellulose fibers (CF) isolated from sugarcane bagasse were used as a reinforcing material, which was impregnated using tannic acid (TA) to improve the strength and antibacterial properties. For the preparation of an antibacterial chitosan-based composite sheet (CBCS), additives, e.g., gelatin and polyvinyl alcohol (PVA), were also added. The CBCS is characterized through FTIR, XRD, UV–vis, SEM, and TGA analysis. With a maximum tensile strength of 29.58 MPa, 86 % elongation, shore hardness of 54 (D), and water absorption of 4.53 %, the prepared CBCS (using 32.7 % of CF) demonstrated improved mechanical properties. Using a bacterial suspension of 1.5 × 105 CFU/mL, the fabricated CBCS sheet demonstrated notable antibacterial properties (71.7 % against E. coli and 63 % against S. aureus). According to the cell cytotoxicity analysis, the Vero cell line also showed a 95 % survival rate without toxicity. In addition, the CBCS exhibited significant biodegradability with a weight loss of 74 % after 120 days. The results suggest effective utilization of sugarcane bagasse and synthesis of hygienically important CBCS that can be exploited in footwear, defense against microbial attack, and excellent biocompatibility, making it suitable for antibacterial shoe insole applications. This understanding could help to eliminate foul odors, bacteria causing infections, ulcerations, and enable potential mitigation of microbial growth within the moist environment around the foot.