Surface modification of cellulose nanofibril films via organosilicon deposition using dielectric barrier discharge plasma (DBD) plasma for packaging applications

Films made of cellulose nanofibrils (CNFs) are promising sustainable alternatives to petroleum-based plastic packaging due to their gas and grease barrier properties, high strength-to-flexibility ratio, tunable transparency, and biodegradability. However, cellulose’s hygroscopic nature limits its direct use in food packaging. Here, we exploit dielectric barrier discharge (DBD) plasma to tune the surface properties of CNF films and improve their water/moisture barrier performance. Two strategies were tested: (i) static-mode deposition of organosilicon fragments using 2,4,6,8-tetramethylcyclotetrasiloxane (TMCTS) as precursor, and (ii) formation of multilayers with varied surface chemistries by adjusting the plasma carrier gas and organosilicon fragment chemistry. Strategy (i) identified process parameters enabling uniform deposition of hydrophobic TMCTS fragments on CNF film surfaces. Strategy (ii) extended this by creating a multilayer structure combining tailored inorganic (hydrophilic) and organic (hydrophobic) layers, which substantially reduced water absorption and improved protection relative to untreated films. These results demonstrate that optimizing plasma gas composition, treatment time, and application mode (static vs. dynamic) allows controlled deposition of chemical moieties, enabling CNF films with tunable water and water–vapor barrier properties suited to diverse food-packaging requirements. Plasma treatment thus offers a sustainable, scalable route to enhance CNF film performance and expand their use in packaging applications.