From self-tubulating cornhusk to green, cheap, high-performance biomass straws

To mitigate environmental pollution caused by plastic straws, wood veneer featuring a two-dimensional (2D) structure has been utilized for producing degradable straws. However, the formation of bendable 2D structures required for straw production typically involves pretreatments such as rotary cutting, chemical activation, and polymer infiltration. Herein, cornhusks possessing inherent self-tubulation properties were employed to produce biomass-based straws featuring tunable inner diameters and lengths via a facile top–down method. Tubular cornhusks were immersed in chitosan solution, followed by twisting and drying/baking to form chitosan–cornhusk straws (chitosan–CHS). A self-tubulation mechanism based on differences in microstructure and volume shrinkage between the inner and outer cornhusk surfaces was proposed. The mechanical performance of chitosan–CHS was comparable to that of plastic and paper straws. The material cost and cradle-to-gate carbon footprint of a single chitosan–CHS were 0.11 cents and 0.057 g CO 2 e, respectively. Theoretically, 1.2 million straws can be produced from 1 hm 2 of cornfield. Overall, by integrating sustainability, cost-effectiveness, scalability, wastewater-free production, biodegradability, recyclability, and a low carbon footprint, chitosan–CHS provide a promising alternative to commercial paper and plastic straws.