Moisture-Induced Self-Strengthening Cellulose Fibers for Textile Applications in a High Humidity Environment

Regenerated cellulose fibers are renowned for their natural origin, environmental sustainability, and soft, skin-friendly texture. However, their application in high-humidity environments is hampered by two major challenges: significant degradation of mechanical properties and susceptibility to bacterial growth. Herein, we develop a waterless wet spinning method to prepare moisture-induced self-strengthening cellulose fibers (MSFs) by introducing calcium sulfate hemihydrate (CSH), which will convert into calcium sulfate dihydrate (CSD) crystals through a hydration reaction after contact with water. Benefiting from participation of the hydroxyl group on cellulose in the hydration reaction, the tensile strength of MSFs increased from 111.7 to 249.4 MPa after storage in high humidity. Additionally, experiments have verified that this moisture-induced self-strengthening phenomenon is also applicable to substances such as MgSO4, CaCl2, and ZnSO4, which crystallize in water. MSFs were endowed with 100% antibacterial properties by replacing CSH with ZnSO4. We believe that cellulose fibers with moisture-induced self-strengthening and good antibacterial properties have great potential for textile applications in a highly humid environment.