A recent publication in Soft Matter (Issue 40, 2018) introduces a novel highly alkaline hydrogel designed to restore the alkaline buffer capacity in carbonated cementitious materials. This property is essential for preventing steel corrosion in reinforced concrete.
The hydrogel is based on a copolymer of diallyldimethylammonium hydroxide (DADMAOH) and methacrylamide. The addition of methacrylamide as a co-neutral monomer allows for extensive tunability of the gel’s rheological properties. The viscosity increases a thousandfold—from 0.35 Pa s to over 350 Pa s—when 10 mol% methacrylamide is used, showcasing the material’s adaptability.
- Ion Exchange: Experiments demonstrated efficient diffusion of hydroxide ions from the hydrogel into carbonated material, accompanied by the release of carbonate ions.
- Re-Alkalisation: The gel’s effectiveness was confirmed through the phenolphthalein test (DIN EN 14630:2007-01) and IR spectroscopy.
- Universal Applicability: The gel can be applied both for modern infrastructure maintenance and the preservation of historical monuments.
Jung, A.; Weichold, O.
Preparation and characterisation of highly alkaline hydrogels for the re-alkalisation of carbonated cementitious materials
Soft Matter 2018, 14 (40), 8105–8111. https://doi.org/10.1039/c8sm01158c.
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