posted on 2023-10-11, 07:03authored byVishnu Arumughan, Hüsamettin
Deniz Özeren, Mikael Hedenqvist, Marie Skepö, Tiina Nypelö, Merima Hasani, Anette Larsson
Integration of fiber
modification step with a modern pulp mill
is a resource efficient way to produce functional fibers. Motivated
by the need to integrate polymer adsorption with the current pulping
system, anion-specific effects in carboxymethylcellulose (CMC) adsorption
have been studied. The QCM-D adsorption experiments revealed that
CMC adsorption to the cellulose model surface is prone to anion-specific
effects. A correlation was observed between the adsorbed CMC and the
degree of hydration of the co-ions present in the magnesium salts.
The presence of a chaotropic co-ion such as nitrate increased the
adsorption of CMC on cellulose compared to the presence of the kosmotropic
sulfate co-ion. However, anion-specificity was not significant in
the case of salts containing zinc cations. The hydration of anions
determines the distribution of the ions at the interface. Chaotropic
ions, such as nitrates, are likely to be distributed near the chaotropic
cellulose surface, causing changes in the ordering of water molecules
and resulting in greater entropy gain once released from the surface,
thus increasing CMC adsorption.