Preparation of cellulose beads with high homogeneity, low crystallinity, and tunable internal structure

The preparation of cellulose beads has attracted much attention in the application of advanced green materials. Herein, the uniform and controllable cellulose beads were prepared by first dissolving the pulp into N-methylmorpholine N-oxide (NMMO), and then regenerated in various coagulation baths (water, alcohol, acid, NMMO, etc.). Results showed that the crystalline structure of regenerated cellulose changed from cellulose I to cellulose II. Besides, the cellulose beads regenerated in Methanol (MT-cellulose bead) had the highest porosity (90.51%) and crystallinity (62.59%). Laser confocal microscopy was employed to reveal the coagulation mechanism of cellulose beads, and the solidification process was carried out from the inside to the outside. This is a green and facile method for preparing cellulose beads with different structures and properties that can be widely used in absorbent materials, energy storage materials, and protein chromatography. Graphical abstract