Colloidal Stability of Aqueous Nanofibrillated Cellulose Dispersions
2011 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 27, no 18, 11332-11338 p.Article in journal (Refereed) Published
Cellulose nanofibrils constitute an attractive raw material for carbon-neutral, biodegradable, nanostructured materials. Aqueous suspensions of these nanofibrils are stabilized by electrostatic repulsion arising from deprotonated carboxyl groups at the fibril surface. In the present work, a new model is developed for predicting colloidal stability by considering deprotonation and electrostatic screening. This model predicts the fibril-fibril interaction potential at a given pH in a given ionic strength environment. Experiments support the model predictions that aggregation is induced by decreasing the pH, thus reducing the surface charge, or by increasing the salt concentration. It is shown that the primary mechanism for aggregation upon the addition of salt is the surface charge reduction through specific interactions of counterions with the deprotonated carboxyl groups, and the screening effect of the salt is of secondary importance.
Place, publisher, year, edition, pages
2011. Vol. 27, no 18, 11332-11338 p.
microfibrillated cellulose, polyelectrolyte, cylinders, surfaces, fibers
IdentifiersURN: urn:nbn:se:kth:diva-41786DOI: 10.1021/la201947xISI: 000294790500010ScopusID: 2-s2.0-80052713583OAI: oai:DiVA.org:kth-41786DiVA: diva2:445267
FunderSwedish Research Council
QC 201506302011-10-032011-10-032015-06-30Bibliographically approved