Adsorption of non-ionic cellulose ethers on cement revisited. (20th January 2019)

• Record Type: Journal Article
• Authors: Hurnaus, Thomas; Plank, Johann
• Is Part Of: Construction & building materials. Volume 195(2019)
• Page Start: 441
• Page End: 449
• Publication Date: 2019-01-20
• Subjects: Cellulose ether -- Cement -- Adsorption -- Depletion -- Zeta potential; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2018.11.020
• Languages: English
• ISSNs: 0950-0618

Abstract

Graphical abstract: Highlights: Currently, non-ionic cellulose ethers (niCEs) are believed to adsorb on cement. The solution depletion of four niCEs from cement slurries was investigated. Retained amounts of niCEs are low, decrease with increasing w/c ratio and DS value. d -glucose, the monomeric unit of niCEs is not retained by silica while niCEs are. niCEs are depleted by entrapment between cement particles, not by adsorption. Abstract: Current literature suggests that non-ionic cellulose ethers (niCEs) adsorb on cement. To clarify whether such interaction occurs indeed, the solution depletion of niCEs from cement slurries was investigated. It was found that the retained amounts of niCEs on cement are generally quite low, decrease with increasing w/c-ratio and are independent of cement composition and surface area. Moreover, d -glucose, cellulose's monomeric unit, was not retained by silica as model substrate, and the zeta potential of the silica suspension was unchanged upon niCE addition. We conclude that niCEs do not adsorb on cement. Instead, the large niCE associates are screened-off in adsorption measurement.