Hollow reversible kapok fibrous membranes with amphiphilicity, natural antibacterial properties, and biodegradability

The demand for exploring biodegradable materials that possess multiple functionalities is rapidly increasing. However, achieving a balance between multiple functional properties is a critical objective that presents a significant challenge. In this study, we have developed multifunctional fibrous membranes with a porous layered structure and high porosity fabricated using alkali-treated kapok fibers via a wet-laid web formation and hot-pressing technique. A noteworthy phenomenon has been observed wherein a fibrous membrane can recover up to 4.49 times its original thickness and restore its hollow structure after being soaked in water for 24 h. This exceptional behavior is attributed to the combined effects of hydration and structure in the kapok fibers. Additionally, the kapok fibrous membrane demonstrates amphiphilic properties, evidenced by contact angles below 42° for water and oil. Furthermore, the membrane exhibits degradation rates of 17.91 % and 74.14 % after 15 and 30 days, respectively. The presence of associated substances and the unique hollow structure inherent in kapok fiber contribute to the outstanding antibacterial efficacy of the fibrous membrane, demonstrating a remarkable inhibition rate of 94 % and 95 % against Escherichia coli and Staphylococcus aureus, respectively. This innovative approach enables the production of versatile biodegradable fibrous membranes with the potential to be utilized in various environmentally-conscious applications, particularly in personal protection and human health.