earticle

영어

Porous, and low-density regenerated cellulose beads (RCBs) have emerged as advanced materials for various engineering applications ranging from chromatography to drug release. Here, 3D porous cellulose beads (CBs) were prepared from the well-dissolved cellulose–TEAOH/urea/H2O solutions via a simple dropping–acid coagulation–freeze drying process. The S-HwBKP with high DP (~1500) were rapidly dissolved at 25 ℃ in a TEAOH/urea solvent system at different molar ratios of TEAOH and urea (T/U = 1:0–1:6), and the dissolved proportion of cellulose was increased from 73.4 to 98.0 wt% with increasing T/U from 1:0 to 1:6. The obtained cellulose–TEAOH/urea solutions with increased T/U molar ratios processed the pronounced surface tension and viscosity, resulting in a bigger size/volume of RCBs via dropping–acid coagulation process. Thereafter, 3D porous RCBs aerogels exhibiting the stable core-shell structure with abundant micro-pores were successfully prepared by freeze-drying method. The slight shrinkage of the freeze-dry RCBs in size and volume was ~11% and ~ 28%, respectively, which was much lower than the oven-dry beads (~64% and ~ 95%). The freeze-dry beads was easily rewet in water and had a good swelling capacity (11.7 g/g). Additionally, its processed lower density (~0.06 g/cm3), high porosity (~91.0%), and thermal/mechanical stabilities, thereby indicating that microporous core-shell structures can be synthesized successfully, and inspiring its widespread design and fabrication on the cellulose-based materials with well-controlled structures via our strategy.