A robust and biodegradable carboxymethyl cellulose-based bioplastic inspired by nacre.

The extensive use of petroleum-based plastics has resulted in critical energy and environmental challenges, driving the pursuit of sustainable and biodegradable bioplastics as ideal alternatives. However, the development of functional bioplastics with superior mechanical strength, water stability, and thermal stability remains a formidable challenge. Herein, inspired by the nacre, a cellulose-based bioplastic was designed with a unique layered architecture and enhanced interfacial interactions，achieved through the self-assembly of carboxymethyl cellulose (CMC) and nano-montmorillonite, while simultaneously forming a chemically and physically double-crosslinked network under the action of TiO nanoparticles and citric acid. The resulting bioplastic demonstrated excellent mechanical performance, with the tensile strength reaching 106.83 MPa, representing a 220.09 % improvement over pure CMC-based bioplastic and surpassing the tensile strength of other CMC-based films. Alongside mechanical prowess, it exhibited exceptional water resistance (water absorption reduced to 42.88 %), thermal stability and UV shielding. Furthermore, it was biodegradable and environmentally benign, capable of achieving complete degradation in the soil within three months. This biomimetic strategy provided a novel approach for developing competitive cellulose-based bioplastics, offering a promising alternative to petroleum-derived plastics for everyday applications.