Estimation of Aspect Ratio of Cellulose Nanocrystals by Viscosity Measurement: Influence of Aspect Ratio Distribution and Ionic Strength
Estimation of Aspect Ratio of Cellulose Nanocrystals by Viscosity Measurement: Influence of Aspect Ratio Distribution and Ionic Strength
复制标题
DOI：
10.3390/polym11050781
复制
发表时间：
2019-05
期刊：
影响因子：
5
通讯作者：
Qiang Wu;Xiuwen Li;Qian Li;Siqun Wang;Yan Luo
中科院分区：
文献类型：
--
作者：
Qiang Wu;Xiuwen Li;Qian Li;Siqun Wang;Yan Luo
研究了纤维素纤维（CNC）长径比（L/d）分布和不同盐离子强度对粘度法估算L/d的影响。通过混合两种不同L/d的CNC来控制L/d分布，所述CNC由木材和细菌纤维素通过酸水解制备。结果表明，L/d分布不影响使用Batchelor方程通过粘度测量估计的CNC L/d的准确性，并且计算的L/d是数均L/d。此外，一价（NaCl），二价（CaCl 2），和三价（AlCl 3）的盐被选择来研究离子强度的影响，通过粘度测量的CNC L/d估计。结果表明，在CNC悬浮液中加入NaCl和CaCl 2可以筛选电粘性效应，并通过粘度测量估算实际物理CNC L/d，而NaCl和CaCl 2的含量可以通过Debye-Hückel理论预测。然而，少量的AlCl 3诱导CNC聚集，并增加特性粘度和预测L/d。
The influence of the cellulose nanocrystal (CNC) aspect ratio (L/d) distribution and ionic strength of different salts on the L/d estimation by viscosity measurement were investigated. The L/d distribution was controlled by mixing two CNC, with different L/d, which were prepared by acid hydrolysis from wood and bacterial cellulose. The results demonstrated that the L/d distribution did not affect the accuracy of the CNC L/d estimated by viscosity measurements using the Batchelor equation, and the calculated L/d was the number-average L/d. Moreover, monovalent (NaCl), divalent (CaCl2), and trivalent (AlCl3) salts were chosen to study the influence of ionic strength on the CNC L/d estimation by viscosity measurement. It was found that NaCl and CaCl2 could be added to the CNC suspension to screen the electro-viscous effect and estimate the actual physical CNC L/d by viscosity measurement, and the content of NaCl and CaCl2 can be predicted by the Debye–Hückel theory. However, a small amount of AlCl3 induced CNC aggregation and increased intrinsic viscosity and predicted L/d.