Preparation of disk-like cellulose particles

Disk-like cellulose particles were facilely prepared by stirring a dispersion of spongy cellulose particles that were prepared with a solvent-releasing method (SRM) with a magnetic stir bar. The obtained particles were thick and disk-like and retained their spongy structure in the wet state. The thick, disk-like particles became thinner in a specific direction upon drying because of capillary force. In contrast, when the same procedure was conducted using cellulose particles with dense structures, the particle shapes were not deformed, and disk-like shapes did not appear. Moreover, when the stirring was carried out using a shaking bath or a touch mixer, the shape transformation was not observed. These results suggest that the spongy structure of the cellulose particles would be a pseudo-plasticization state, which can cause the cellulose particles to deform. The disk-like particles formed as a result of the grinding of spongy cellulose particles between the stir bar and the vial. The number of disk-like particles and the degree of deformation increased with increasing of the stirring time, the speed and the contact area.