Rheological properties of nanocellulose suspensions: effects of fibril/particle dimensions and surface characteristics
Artikel i vetenskaplig tidskrift, 2017

The rheological properties of aqueous suspensions based on three different nanocelluloses were compared. One system was obtained via acid hydrolysis (thus yielding crystalline nanocellulose, CNC) and the other two from mechanical shearing, but from different origins and subjected to different pretreatments. Of the latter two, one was considered to be a rather typical cellulose nanofibril (CNF) suspension whereas the other was a kind of intermediate between CNF and CNC. All three nanocellulose elements differed in dimensions as evident from transmission electron microscopy and atomic force microscopy. With regard to the length of the fibrils/particles, the three nanocelluloses formed three distinct groups with lengths between 200 and slightly more than 800 nm. The three cellulosic elements were also subjected to a TEMPO-mediated oxidation yielding a similar carboxylate content in the three systems. Furthermore, the TEMPO-oxidized elements were grafted with poly(ethylene glycol) (PEG). The amount of grafted PEG was about 35 wt%. The shear viscosity, the storage modulus and the loss modulus of suspensions of the unmodified, the TEMPO-oxidized and the grafted nanocelluloses were determined at room temperature and the solids content of the suspensions was varied between 0.7 and 2.0 wt%. It was concluded that the rheological properties varied significantly between the suspensions depending on the dimensions of the cellulosic elements and their surface characteristics. In this context, the length (or the aspect ratio) of the particles played a very important role.

rheology

surface characteristics

cellulose nanofibrils

cellulose nanocrystals

Författare

Tobias Moberg

Chalmers, Material- och tillverkningsteknik, Polymera material och kompositer

Karin Sahlin

Chalmers, Kemi och kemiteknik, Kemi och biokemi, Organisk kemi

Kun Yao

Kungliga Tekniska Högskolan (KTH)

Shiyu Geng

Kungliga Tekniska Högskolan (KTH)

Luleå tekniska universitet

Gunnar Westman

Wallenberg Wood Science Center (WWSC)

Chalmers, Kemi och kemiteknik, Kemi och biokemi, Organisk kemi

Q. Zhou

Kungliga Tekniska Högskolan (KTH)

Kristiina Oksman

Kungliga Tekniska Högskolan (KTH)

Luleå tekniska universitet

Mikael Rigdahl

Wallenberg Wood Science Center (WWSC)

Chalmers, Material- och tillverkningsteknik, Polymera material och kompositer

Cellulose

0969-0239 (ISSN)

Vol. 24 2499-2510

Drivkrafter

Hållbar utveckling

Styrkeområden

Nanovetenskap och nanoteknik

Materialvetenskap

Ämneskategorier

Pappers-, massa- och fiberteknik

DOI

10.1007/s10570-017-1283-0