Chapter 10 - Nanocellulose and its composite films: Applications, properties, fabrication methods, and their limitations

Abstract

Nanocellulose (NC) is a biodegradable nanomaterial produced from lignocellulosic biomass. Mechanical, chemical, or enzymatic processes are normally used for the defibrillation of wood fibers into nanofibrils. It is a network of fibrillar cellulosic material in which there is a very wide range of fibrillar diameter. This material has unique characteristics leading to potential applications in fabricating various functional materials. These nanomaterials can be used as a base substrate or in coatings, and as an alternative for synthetic plastic substrates and plastic laminates. These nanomaterials possess good barrier properties, although often still inferior to synthetic plastics, excellent mechanical strength and are biodegradable NC films and their composites have been used in developing functional materials such as barrier materials, substrates for printing circuits in flexible electronics, barrier coatings on the paper and paper board etc. In addition, there is a potential demand for NC films and composites to replace or eliminate conventional plastics. There are many methods available to prepare free-standing NC films and composites and these are critically reviewed and addressed in this chapter. Conventional methods are seen to be time-consuming, and unable to produce outstanding quality films, and hence set limitations on commercialization. Therefore, a rapid process to produce the NC films is required to meet the potentially large requirement for packaging and other functional material.