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Anion-Specific Adsorption of Carboxymethyl Cellulose on Cellulose
journal contributionposted on 2023-10-11, 07:03 authored by Vishnu 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.
resource efficient wayproduce functional fibersmodern pulp millgreater entropy gainfiber modification stepcurrent pulping systemintegrate polymer adsorptionadsorption experiments revealedkosmotropic sulfate cocellulose model surfacechaotropic cellulose surfacecellulose integrationcellulose comparedcarboxymethyl cellulosechaotropic cospecific adsorptionwater moleculesspecific effectsnitrate increasedmagnesium saltsdistributed nearchaotropic ionscausing changesanions determines