Scalable ultrastrong bamboo strips via interfacial homogeneous fusion

Ultrastrong bamboo is a lightweight, high-strength material with application potential exceeding that of natural bamboo. However, its high strength is not preserved in longer macroscopic assemblies for practical applications, which exhibit substantially inferior tensile strength (∼363 MPa). To address this challenge, we designed a scalable ultrastrong bamboo strip (SUS-bamboo) featuring a structure with interfacial homogeneous fusion through a self-reinforcing strategy. This enhancement was achieved by a significant increase in the interfacial hydrogen-bond density via the synergistic effect of exposed nanofibers on the fiber surface and in situ dissolved regenerated cellulose nanofibrils. The SUS-bamboo exhibited a tensile strength of 942 MPa in macroscopic assembled form, which was 3.5 times that of the conventional assembly. The lower-cost, node-containing, scalable ultrastrong bamboo achieved a tensile strength of 553 MPa (two-layer bonded). This study provided an advanced strategy for the design and application of sustainable bamboo composites.