Carboxymethylated nanofibrillated cellulose: effect of monovalent electrolytes on the rheological properties
- 538 Downloads
The effect of the ionic strength on the properties of a carboxymethylated nanofibrillated cellulose (NFC) system was investigated through rheological studies. It was shown that homogenization of pulp suspensions containing a high amount of a monovalent electrolyte leads to the production of NFC systems displaying a lower magnitude in the rheological response as compared with systems prepared at lower ionic strengths conditions. It was further shown that increasing the ionic strength of NFC suspensions after their manufacturing also results in a lowering of the rheological response. The decreased rheological response in the former case was postulated to be caused by a lowering of the delamination deficiency of the homogenization process, due to decreased swelling of the carboxymethylated pulp, caused by the screening of the charges. In the latter case (post-addition of the electrolyte), the lowering of the rheological response was postulated to be due to the compression of the electrostatic double layer, when the electrostatic repulsion between the charged fibrils diminished in the presence of the electrolyte.
KeywordsNanofibrillated cellulose NFC Homogenization Charge density Rheology Ionic strength
Åsa Engström is thanked for her competent supporting work. Billerud-Korsnäs, Borregaard, De la Rue, Hansol Holmen, Kemira, Korsnäs, Metsä Group, Stora Enso, Södra, Evergreen Packaging and UPM are acknowledged for their financial support.
- Eichhorn SJ, Dufresne A, Aranguren M, Marcovich NE, Capadona JR, Rowan SJ, Weder C, Thielemens W, Roman M, Renneckar S, Gindl W, Veigel S, Keckes J, Yano H, Abe K, Nogio M, Nakagaito AN, Mangalam A, Simonsen J, Benight AS, Bismarck A, Berglund LA, Peijs T (2010) Review: current international research into cellulose nanofibres and nanocomposites. J Matter Sci 45(1):1–33CrossRefGoogle Scholar
- Herrick FW, Casebier RL, Hamilton JK, Sandberg KR (1983) Microfibrillated cellulose: morphology and accessibility. J Appl Polym Sci Appl Polym Symp 37:797–813Google Scholar
- Jowkarderis L, van de Ven TM (2014) Intrinsic viscosity of aqueous suspensions of cellulose nanofibrils. Cellulose 1–7. doi: 10.1007/s10570-014-0292-5
- Lindström T, Aulin C, Naderi A, Ankerfors M (2014) Microfibrillated cellulose. In: Encyclopedia of polymer science and technology. Wiley, pp 1–34. doi: 10.1002/0471440264.pst614
- Pääkkö M, Ankerfors M, Kosonen H, Nykänen A, Ahola S, Österberg M, Ruokolainen J, Laine J, Larsson PT, Ikkala O, Lindström T (2007) Enzymatic hydrolysis combined with mechanical shearing and high-pressure homogenization for nanoscale cellulose fibrils and strong gels. Biomacromolecules 8(6):1934–1941. doi: 10.1021/bm061215p CrossRefGoogle Scholar
- Tanaka R, Saito T, Ishii D, Isogai A (2014) Determination of nanocellulose fibril length by shear viscosity measurement. Cellulose 1–9. doi: 10.1007/s10570-014-0196-4