Ultrasonication of spray- and freeze-dried cellulose nanocrystals in water

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:516

Article

Beuguel, Quentin¹  Tavares, Jason R.¹  Carreau, Pierre J.¹  Heuzey, Marie-Claude¹ 

[1] Polytech Montreal, CREPEC Res Ctr High Performance Polymer & Composi, Dept Chem Engn, Montreal, PQ H3T 1J4, Canada

关键词: Cellulose nanocrystals (CNCs);    Spray drying;    Ultrasonication;    Aqueous suspension;    Structure;    Rheology;   

DOI  :  10.1016/j.jcis.2018.01.035

来源: Elsevier

【 摘 要 】

The structural and Theological properties of aqueous suspensions of spray-dried cellulose nanocrystals (CNCs) were investigated and compared to those of freeze-dried. The cellulose nanocrystals were obtained from sulfuric acid hydrolysis of wood pulp. Ultrasonication was used to disperse cellulose nanocrystals in Milli-Q water and the power applied during ultrasonication was shown to be the controlling parameter for their dispersion, more than total energy. Dynamic light scattering measurements showed a decrease of the average hydrodynamic diameter down to the same limiting value, i.e. similar to 75 nm, for both spray and freeze-dried cellulose nanocrystals. Since the same maximum dispersion state was reached for both CNC types, it indicated that the spray drying process did not limit dispersion, provided that sufficient ultrasonication was provided. Moreover, no desulfation occurred during ultrasonication at ambient temperature. Strong ultrasonication also caused a decrease of intrinsic viscosity, along with an increase in maximum packing concentration. These properties were correlated to agglomerates break-up, which released both ions and water in suspension. The ionic strength increase may lead to a thinner electrostatic double layer surrounding the cellulose nanocrystals, reducing their apparent concentration. (C) 2018 Elsevier Inc. All rights reserved.

【 授权许可】

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