Review On: Current Research Applications of Cellulose Nanocrystals, Its Sources, Fabrication Methods, and Properties

In the 21st century, cellulose based nano-sized materials will be regarded as an innovative matter that encouraging production of high value-added pulp and paper products, and provide solutions for technological innovations for various applications. Recently, there is a wide range of cellulose based nano-materials that have been extracted, and developed for various applications. The current research interest is towards conducting a large scale research and development activities on numerous applications of nano-materials for commerical use. Cellulose nanofiber is a eco-friendly materials with a potential applications as reinforced filler in various composites, targeted drug delivery, smart materials, 3D printing, and automotive interior parts. The first cellulose nanofiber or micelles was chemically (acid hydrolysis) extracted by Ranby in 1949. Based on fabrication techniques, cellulose nanofibers can be categorized into cellulose nanocrystals, nanofibrillated celulose and TEMPO cellulose nanofibers. Cellulose nanofibers can be extracted by top down and bottom up approaches such as mechanical, enzymatic hydrolysis, TEMPO, acid hydrolysis and production of bacterial cellulose respectively. In recent years, the use of cellulose nanocrystals for different applications have gained much research interest because they are bio-degradable, biocompatible, carbon neutral, and readily available from renewable resources. In the acid hydrolysis process, the cellulose nanocrystals (CNCs) amorphous regions are destroyed while the crystalline domains are kept intact. In this review chapter, the recent developments on research and applications of cellulose nanocrystal extracted by acid hydrolysis will be discussed. This chapter aims to provide a detailed description on i) Cellulose nanocrystals isolation methods, characterization, and properties ii) Current and future trends in terms of development of CNCs for various applications and iii) Concluding remarks on cellulose nanocrystals major use in advanced engineering applications such as composites, smart materials, electronic devices, automobile interiors, surface coating, used as a lubricant, transparent films, targeted drug delivery and etc.