Continuously enhanced versatile nanocellulose films enabled by sustaining CO₂ capture and in-situ calcification

Cellulose possesses numerous favorable peculiarities to replace petroleum-based materials. Nevertheless, the extremely high hygroscopicity of cellulose severely degrades their mechanical performance, which is a major obstacle to the production of high-strength, multi-functional cellulose-based materials. In this work, a simple strategy was proposed to fabricate durable versatile nanocellulose films based on sustaining CO₂ capture and in-situ calcification. In this strategy, Ca(OH)₂ was in-situ formed on the films by Ca²⁺ crosslinking and subsequent introduction of OH^-, which endowed the films with high mechanical strength and carbon sequestration ability. The following CO₂ absorption process continuously improved the water resistance and durability of the films, and enabled them to maintain excellent mechanical properties and promising light management ability. After a 30-day CO₂ absorption process, the water contact angle of the films can be increased from 43° to 79°, and the weight gain rate of the films in a 30 h water-absorption process can be sharply decreased from 331.2 % to 52.2 %. The films could maintain a high tensile strength of 340 MPa, and result in a CO₂ absorption rate of 3.5 mmol/g_cellulose after 30 days. In this study, the improvement of durability and carbon sequestration of nanocellulose films was achieved by a simple and effective method.