Mechanically strong micro-nano fibrillated cellulose paper with improved barrier and water-resistant properties for replacing plastic

Replacing nonbiodegradable plastics with environmentally friendly cellulose materials has emerged as a key trend in environmental protection. This study highlights the development of a strong and hydrophobic micro-nano fibrillated cellulose paper (MNP) through the incorporation of micro-nano fibrillated cellulose fiber (MNF) and chitin nanocrystal (Ch), followed by the impregnation of polymethylsiloxane (PMHS). A low-acid, heat-assisted colloidal grinding strategy was employed to prepare MNF with a high aspect ratio effectively. Ch was incorporated as a reinforcing matrix into the cellulose fiber scaffold through straightforward mechanical mixing and mechanical hot-pressing treatments. Compared to pure MNP, the 5Ch-MNP exhibited a 25 % improvement in tensile strength, reaching 170 MPa, and showed enhanced barrier properties against oxygen and water vapor. The impregnation of PMHS rapidly confers environmentally resistant hydrophobic properties to 1 % PMHS-5Ch-MNP, leading to a water contact angle exceeding 112°, and a 290 % increase in tensile strength under wet conditions. Additionally, the paper demonstrated excellent antibacterial adhesion properties, with the adhesion rates for E. coli and S. aureus exceeding 98 %. This study successfully produced functional cellulose paper with remarkable mechanical properties and barrier properties, as well as hydrophobicity, using a simple, efficient, and environmentally friendly method, making it a promising substitute for petroleum-based plastics.