Aerogel, a highly porous material, is attracting increasing attention owing to low thermal conductivity and high specific surface area. Freeze-drying technology has been employed to produce nano-cellulose aerogels; however, the resultant product has low specific surface areas. Here, a modified approach to prepare nano-cellulose aerogels was reported, which involves tert-butyl alcohol as a solvent. Nano-cellulose aerogels were prepared via a spontaneous gelation fashion using calcium chloride solution, followed by tert-butyl alcohol solvent displacement and freeze drying. Addition of calcium chloride (0.25%) accelerated the physical gelation process. The application of tert-butyl alcohol as a solvent contributed to preservation of gel network. The obtained spherical nano-cellulose aerogels had a shrinkage rate of 5.89%. The specific surface area and average pore size was 164. 9666 m2 g−1 and 10.01 nm, respectively. Additionally, nano-cellulose aerogels had a comparable thermal degradation property when compared to microcrystalline cellulose. These biophysical properties make nano-cellulose aerogels as a promising absorption material.

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叔丁醇用于通过冷冻干燥技术制备纳米纤维素气凝胶

气凝胶是一种高度多孔的材料，由于其低导热性和高比表面积而受到越来越多的关注。采用冷冻干燥技术生产纳米纤维素气凝胶；然而，所得产品的比表面积低。在这里，报道了一种制备纳米纤维素气凝胶的改进方法，其中包括叔丁醇作为溶剂。使用氯化钙溶液通过自发凝胶方式制备纳米纤维素气凝胶，然后用叔丁醇溶剂置换和冷冻干燥。添加氯化钙 (0.25%) 加速了物理凝胶化过程。叔丁醇作为溶剂的应用有助于凝胶网络的保存。所得球形纳米纤维素气凝胶的收缩率为5.89%。比表面积和平均孔径分别为 164. 9666 m2 g-1 和 10.01 nm。此外，与微晶纤维素相比，纳米纤维素气凝胶具有相当的热降解性能。这些生物物理特性使纳米纤维素气凝胶成为一种很有前途的吸收材料。