Hybrid microstructure of smectite clay gels revealed using neutron and synchrotron X-ray scattering

Aqueous suspensions of swelling clays display a nematic sol-gel transition at very low solid concentrations. The underlying microstructure of the gel has remained a point of contention since the time of Irving Langmuir and has been a major obstacle to fully realizing the potential of clays for practical applications. Here, we comprehensively probe the microstructure of a smectite clay suspension using ultra-small angle neutron/X-ray scattering and find that the nematic gel is structurally ordered and contains entities that are at least an order of magnitude larger than the individual particles. Complementary cryo-electron microscopy shows the presence of domains having particle-particle ordering responsible for nematic texture and regions of particle-particle aggregation responsible for gel-like behavior. We find that the smectic clay gels have a hybrid microstructure with co-existing repulsive nematic domains and attractive disordered domains. © 2023 The Author(s). Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License.

Keywords

Colloids, Liquid crystals, Materials, Microstructure, Smectite, Clays, Gels, Neutron diffraction, Synchrotrons, X-ray diffraction

Citation

Shoaib, M., Khan, S., Wani, O. B., Mata, J., Krzysko, A. J., Kuzmenko, I., Bluel, M., Fiddes, L. F., Roth, E. W., & Bobicki, E. R. (2023). Hybrid microstructure of smectite clay gels revealed using neutron and synchrotron X-ray scattering. Communications Materials, 4(1), 93. doi:10.1038/s43246-023-00414-y

URI

https://apo.ansto.gov.au/handle/10238/15332

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