Free standing nanocellulose films – fabrication methods, surface engineering and recyclability

Free-standing nanocellulose films are among the predominant products derived from nanocellulose-based nanomaterials. These films have the potential to serve as alternatives to synthetic plastics in various applications. This review highlights the capacity of nanocellulose to develop films primarily used as barrier materials. Several methods are available for fabricating free-standing nanocellulose films and their composites. However, traditional techniques such as solvent casting and vacuum filtration are often time-consuming in the formation of wet films. Therefore, there is a need for faster fabrication methods. Spray coating emerges as a rapid and flexible process that accelerates the formation of nanocellulose films by spraying nanocellulose suspension onto polished stainless-steel surfaces. This method allows for surface engineering of the films, enabling the development of functional materials such as barriers and substrates for flexible electronics. The review summarizes various fabrication approaches suitable for large-scale production, emphasizing their efficiency and scalability. Additionally, considerations regarding the recyclability and surface engineering of nanocellulose films are discussed, highlighting their potential as functional materials within a circular economy framework. Nanocellulose films offer a sustainable alternative to conventional plastics, contributing to environmental conservation. Moreover, nanocellulose is an eco-friendly material with the capacity to combat microplastics and nanoplastics originating from synthetic plastics, thus supporting efforts toward reducing plastic pollution and promoting sustainability.