Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Aug 12;41(31):20463-20480.
doi: 10.1021/acs.langmuir.5c00966. Epub 2025 Jul 31.

Unveiling the Structure and Dynamics of Water Confined in Colloidal Boehmite Suspensions

Affiliations

Unveiling the Structure and Dynamics of Water Confined in Colloidal Boehmite Suspensions

Lawrence M Anovitz et al. Langmuir. .

Abstract

Thin fluid layers confined between nanoparticles play an important role in several natural and industrial systems, including radioactive wastes stored in tanks at the U.S. Department of Energy's Hanford site. Multimodal neutron and computational approaches have been integrated to examine the properties of one, two, and four layers of water (H2O or D2O) on nanoparticulate, hydrous, or deuterated boehmite (γ-AlOOH or γ-AlOOD). Exposure of deuterated boehmite to H2O at 90 °C yielded rapid H/D isotopic exchange likely driven by a Grotthus-like proton-hopping mechanism. The in-plane and out-of-plane vibrations of the structural hydroxyls involved in this exchange were observed for both the hydrated and deuterated boehmite. These observations were confirmed by molecular dynamics simulations that also showed that single water molecules on the (010) surface bond to the structure via four bonds: two from hydrogens (deuteriums) on the water to surrounding oxygens and two from the water's oxygen to surrounding OD/OH. Bulk water-like properties began to appear once four monolayers of water had been added, but steric crowding limited water diffusion rates once two monolayers had been added. The super-Arrhenius temperature dependence observed at four monolayers indicated glass-like behavior in a well-formed hydrogen-bonding network. Such a network is not sufficiently developed, however, when the surface water coverage is less than four layers. The unique nature of these layers can provide critical information for understanding forces between particles in proximity, and resultant effects on suspension rheology.

PubMed Disclaimer

LinkOut - more resources