Relationship between aspect ratio and suspension viscosity of wood cellulose nanofibers
Relationship between aspect ratio and suspension viscosity of wood cellulose nanofibers
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DOI：
10.1038/pj.2013.64
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发表时间：
2014-01-01
期刊：
影响因子：
2.8
通讯作者：
Endo, Takashi
中科院分区：
文献类型：
--
作者：
Iwamoto, Shinichiro;Lee, Seung-Hwan;Endo, Takashi
以木材为原料，通过酸水解和机械粉碎制备了长径比为30-300的纤维素纳米纤维。从原子力显微镜（AFM）图像测量单个CNF的长度和宽度。采用锥板式流变仪和毛细管流变仪测定了CNF悬浮液的稳态剪切特性，测定了其特性粘度。高长径比的CNF具有较大的特性粘度值。刚性杆理论的基础上预测的纵横比最低的纵横比CNFs符合我们的测量值。然而，对于高纵横比的CNFs，预测值与实验值不一致。与其他类型的颗粒和聚合物的CNF特性粘度的比较表明，CNF是半柔性棒，而不是刚性棒。
Cellulose nanofibers (CNFs) with aspect ratios varying from 30-300 were prepared from wood by acid hydrolysis and mechanical disintegration. The length and width of the individual CNFs were measured from atomic force microscopy (AFM) images. The steady shear properties of the CNF suspensions were measured using cone-plate type and capillary rheometers to determine their intrinsic viscosities. Higher aspect ratio CNFs had larger intrinsic viscosity values. The predicted aspect ratios on the basis of rigid rod theory for the lowest aspect ratio CNFs corresponded well with our measured values. However, for higher aspect ratio CNFs, the predicted values did not agree with the experimental values. A comparison of the CNF intrinsic viscosities with other types of particles and polymers indicated that the CNFs are semi-flexible rods rather than rigid rods.