Cellulose nanosphere: Preparation and applications of the novel nanocellulose.

Over the past few years, cellulose nanosphere (CNS) has gained growing attention and rapid development. As a new type of nanocellulose materials, CNS can be prepared from native cellulose by using methods which have been adopted extensively to prepare the well-known nanocelluloses, i.e., cellulose nanofiber and cellulose nanocrystal. The particular interest is that the regenerated cellulose and mercerized cellulose can also be used as important feedstocks to produce CNS. In this review, the preparation methods of CNS are described and discussed, via both top-down processes, including chemical, mechanical, and enzymolysis ones, and bottom-up processes by using various cellulose I and II starting materials. This review also highlights the researches relative to cellulose composite nanospheres, and summarizes the applications of spherical cellulose-based nanoparticles. Finally, the future challenges and opportunities of CNS are prospected in this work. • A novel nanocellulose material, cellulose nanospheres, is reviewed. • The preparation of the spherical nanocellulose via top-down and bottom-up processes are presented. • The application of cellulose and cellulose composite nanospheres are also included. [ABSTRACT FROM AUTHOR]