Morphology and Flow Behavior of Cellulose Nanofibers Dispersed in Glycols
Morphology and Flow Behavior of Cellulose Nanofibers Dispersed in Glycols
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DOI：
10.1021/acs.macromol.9b01036
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发表时间：
2019-07
期刊：
影响因子：
5.5
通讯作者：
Ruifu Wang;T. Rosén;Chengbo Zhan;S. Chodankar;Jiahui Chen;P. Sharma;S. Sharma;Tianbo Liu;B. Hsiao
中科院分区：
文献类型：
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作者：
Ruifu Wang;T. Rosén;Chengbo Zhan;S. Chodankar;Jiahui Chen;P. Sharma;S. Sharma;Tianbo Liu;B. Hsiao
了解分散在有机溶剂中的纤维素纳米纤维(CNF)的形态和流动行为有助于改进新型纤维素基纳米复合材料的制备工艺。本研究采用溶剂交换法将黄麻基2，2，6，6-四甲基哌啶-1-氧基(TEMPO)氧化的碳纳米纤维分别分散在乙二醇(EG)和丙二醇(PG)中，其电荷密度分别为0.64和1.03 mmol/g。用透射电子显微镜、原子力显微镜和小角X射线散射技术对干燥和悬浮状态下碳纳米纤维的形貌和尺寸进行了表征。结果表明，在不同的溶剂中，其横截面尺寸保持不变。流变学测量表明，CNF在水或乙二醇(EG和PG)中的悬浮液表现出与典型聚合物溶液相似的行为，其与溶剂无关的重叠浓度对应的拥挤因子约为14。此外，在浓缩的CNF/PG体系中发现了触变性行为.
Understanding the morphology and flow behavior of cellulose nanofibers (CNFs) dispersed in organic solvents can improve the process of fabricating new cellulose-based nanocomposites. In this study, jute-based 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO)-oxidized CNFs with two different charge densities (0.64 and 1.03 mmol/g) were dispersed in ethylene glycol (EG) and propylene glycol (PG) using the solvent exchange method. The morphology and dimensions of CNFs in dry and suspension states were characterized using transmission electron microscopy, atomic force microscopy, and small-angle X-ray scattering techniques. The results showed that the cross-sectional dimensions remained the same in different solvents. Rheological measurements revealed that CNF suspensions in water or glycol (EG and PG) behaved similar to typical polymer solutions with a solvent-independent overlap concentration corresponding to the crowding factor of about 14. Furthermore, a thixotropic behavior was found in the concentrated CNF/...