Adsorbent semi-transparent cellulose-based self-standing thin films

Cellulose-based materials are emerging as versatile candidates for sustainable functional materials. This study presents a straightforward process to fabricate cellulose-based, self-standing films using 12 wt% microcrystalline cellulose (MCC) in an aqueous solution of 40 wt% tetrabutylammonium hydroxide (TBAH). TBAH, as an out-of-equilibrium solvent capable of dissolving MCC, is utilized to fabricate self-standing cellulose films through gelation induced by cellulose I-cellulose II precipitation. The films exhibit moderate mechanical properties, with a Young's modulus approximately 460 MPa, tensile strength ranging from 1 to 4 MPa, and an elongation at break of about 2 %. The incorporation of zinc salts (0.2 M) does not significantly affect the overall mechanical properties. Their long-term stability is ensured by TBAH and zinc salts, both of which are known to prevent microbial growth. These films demonstrate a strong adsorption capacity for water-soluble contaminants like methylene blue, making them valuable for wastewater treatment and dye detection. Their multifunctional attributes position them as sustainable materials for advanced applications, including antimicrobial packaging, water purification systems, and potentially biomedical technologies. Overall, these cellulose-based films offer promising solutions for critical global challenges.