Adsorption of Xyloglucan onto Cellulose Surfaces of Different Morphologies: An Entropy-Driven Process
2016 (English)In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 17, no 9, 2801-2811 p.Article in journal (Refereed) Published
The temperature-dependence of xyloglucan (XG) adsorption onto smooth cellulose model films regenerated from N-methylmorpholine N-oxide (NMMO) was investigated using surface plasmon resonance spectroscopy, and it was found that the adsorbed amount increased with increasing temperature. This implies that the adsorption of XG to NMMO-regenerated cellulose is endothermic and supports the hypothesis that the adsorption of XG onto cellulose is an entropy-driven process. We suggest that XG adsorption is mainly driven by the release of water molecules from the highly hydrated cellulose surfaces and from the XG molecules, rather than through hydrogen bonding and van der Waals forces as previously suggested. To test this hypothesis, the adsorption of XG onto cellulose was studied using cellulose films with different morphologies prepared from cellulose nanocrystals (CNC), semicrystalline NMMO-regenerated cellulose, and amorphous cellulose regenerated from lithium chloride/dimethylacetamide. The total amount of high molecular weight xyloglucan (XGHMW) adsorbed was studied by quartz crystal microbalance and reflectometry measurements, and it was found that the adsorption was greatest on the amorphous cellulose followed by the CNC and NMMO-regenerated cellulose films. There was a significant correlation between the cellulose dry film thickness and the adsorbed XG amount, indicating that XG penetrated into the films. There was also a correlation between the swelling of the films and the adsorbed amounts and conformation of XG, which further strengthened the conclusion that the water content and the subsequent release of the water upon adsorption are important components of the adsorption process.
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2016. Vol. 17, no 9, 2801-2811 p.
Adsorption, Amorphous films, Cellulose, Entropy, Hydrogen bonds, Molecules, Oxide films, Polymers, Surface plasmon resonance, Temperature distribution, Van der Waals forces, Cellulose nanocrystal (CNC), High molecular weight, Increasing temperatures, N methylmorpholine N oxide, Reflectometry measurements, Regenerated cellulose films, Surface plasmon resonance spectroscopy, Temperature dependence
Nano Technology Paper, Pulp and Fiber Technology Polymer Chemistry Physical Chemistry Polymer Technologies
Research subject Fibre and Polymer Science
IdentifiersURN: urn:nbn:se:kth:diva-193110DOI: 10.1021/acs.biomac.6b00561ISI: 000383213200004PubMedID: 27476615ScopusID: 2-s2.0-84986911764OAI: oai:DiVA.org:kth-193110DiVA: diva2:975200
FunderKnowledge FoundationSwedish Foundation for Strategic Research Knut and Alice Wallenberg Foundation
QC 201610052016-09-292016-09-292016-10-17Bibliographically approved