Dynamic and Static Assembly of Sulfated Cellulose Nanocrystals with Alkali Metal Counter Cations
Artikel i vetenskaplig tidskrift, 2022

Sulfate groups on cellulose particles such as cellulose nanocrystals (CNCs) provide colloidal stability credit to electrostatic repulsion between the like-charged particles. The introduction of sodium counter cations on the sulfate groups enables drying of the CNC suspensions without irreversible aggregation. Less is known about the effect of other counter cations than sodium on extending the properties of the CNC particles. Here, we introduce the alkali metal counter cations, Li+, Na+, K+, Rb+, and Cs+, on sulfated CNCs without an ion exchange resin, which, so far, has been a common practice. We demonstrate that the facile ion exchange is an efficient method to exchange to any alkali metal cation of sulfate half esters, with exchange rates between 76 and 89%. The ability to form liquid crystalline order in rest was observed by the presence of birefringence patterns and followed the Hofmeister series prediction of a decreasing ability to form anisotropy with an increasing element number. However, we observed the K-CNC rheology and birefringence as a stand-out case within the series of alkali metal modifications, with dynamic moduli and loss tangent indicating a network disruptive effect compared to the other counter cations, whereas observation of the development of birefringence patterns in flow showed the absence of self- or dynamically-assembled liquid crystalline order.

rheo-PLI

cellulose nanocrystals

rheology

ion exchange

ion pairs

birefringence

Författare

P. Petschacher

Technische Universität Graz

Reza Ghanbari

Chalmers, Industri- och materialvetenskap, Konstruktionsmaterial

C. Sampl

Technische Universität Graz

H. Wiltsche

Technische Universität Graz

Roland Kádár

Chalmers, Industri- och materialvetenskap, Konstruktionsmaterial

Stefan Spirk

Tiina Nypelö

Chalmers, Kemi och kemiteknik, Tillämpad kemi

Nanomaterials

20794991 (eISSN)

Vol. 12 3131

Development of a new rheometer system at MAX IV

Stiftelsen Chalmers tekniska högskola, 2019-03-01 -- 2021-12-31.

Max IV-laboratoriet, 2019-03-01 -- 2021-12-31.

Advanced rheometry of CNC based systems

Wallenberg Wood Science Center (WWSC), 2019-01-01 -- 2024-12-31.

Ämneskategorier

Annan maskinteknik

Pappers-, massa- och fiberteknik

Infrastruktur

Chalmers materialanalyslaboratorium

Styrkeområden

Materialvetenskap

DOI

10.3390/nano12183131

Mer information

Senast uppdaterat

2024-01-03