Processing wheat straw into strong and flexible cellulose fiber bundle: Waste-to-wealth strategy

The excessive reliance on traditional petroleum resources poses significant environmental challenges. Fortunately, agricultural straw, which is often regarded as a waste product, has considerable potential for various applications. However, these materials are frequently crushed into particles, thereby neglecting their inherent structural advantages. In this study, wheat straw is utilized in its complete form and converted to a strong and flexible fiber bundle. We employ a top-down approach on whole wheat straw that involves an alkali pretreatment combined with delignification and freeze-drying to obtain highly directional cellulose aggregates. Subsequent twist densification results in the formation of a strong, flexible wheat straw-derived fiber bundle (WFB). WFB exhibits an excellent strength of 203.9 MPa, representing a 3.4 improvement rate in relation to that of the initial straw. This indicates that agricultural waste can be transformed to a high-performance material, embodying the concept of "Waste to Wealth." In addition, WFB can be further functionalized (e.g., via hydrophobic treatment, dyeing treatment, or incorporation with a conductive material) on the basis of the abundant hydroxyl groups present on its surface. This strategy provides insights into the innovative utilization of straw and promotes its application in wearable textile and smart fiber development.