Effects of Inorganic Salt Electrolytes on the Rheological Properties of Nanocellulose [无机盐电解质对纳米纤维素流变性能的影响]

作者：Li X.; Zhang L.; Chang H.; Wang N.; Zhang Z.^*; Chen L.

来源：China Pulp and Paper, 2020, 39(12): 9-17.

DOI：10.11980/j.issn.0254-508X.2020.12.002

• Cellulose nanocrystal
• Cellulose nanofibril
• Ionic strength
• Rheological properties

In this study, the effect of inorganic salt electrolytes of different anions and cations on the rheological properties of nanocellulose suspension was explored. The results showed that the suspension of cellulose nanofibril (CNF) and cellulose nanocrystal (CNC) had a "shear thinning" behavior. When the shear rate increased from 0.01 s-1 to 1000 s-1, the viscosity of the suspension decreased continuously from 1000 Pa?s to 0.1 Pa?s. When different valence metal salts NaCl, MgCl2, AlCl3, Na2CO3 and Na3PO4 were added to the nanocellulose suspension, with the increase of metal salt content from 0.001 mol/L to 0.5 mol/L, the double electrical layer on the nanocellulose surface was destroyed and the electrostatic repulsion force was weakened. Thus, the nanocellulose particles were deposited and aggregated, and the nanocellulose suspension was gelled. In addition, as the cation strength increased, the gelation became more and more obvious. Correspondingly, the viscosity of the suspension increased, and the storage modulus and loss modulus also increased. In contrast, influenced by the "electrostatic repulsion effect" of metal ions, the viscosity and modulus of suspension at the increase of anionic strength had little change, the anions had no obvious damage to the double layer on the surface of the nanocellulose, so the interaction between nanocellulose could not be significantly reduced. Therefore, the increase of anionic strength had little effect on the gelation of nanocellulose suspension.

• 单位
  制浆造纸工程国家重点实验室; 华南理工大学