Rheological analysis of oil–water emulsions stabilized with clay particles by LAOS and interfacial shear moduli measurements
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Clay particles (montmorillonite) induced stabilization in oil–water emulsions in different ways depending on their localization. Regardless of the localization, an emulsion showed a plateau in G′ and a local peak in G″ under small strain. During large-amplitude shear tests, an emulsion with clays selectively localized in the oil phase demonstrated local minima in G′ and G″ while an emulsion with an interfacial layer of clays showed a strain thinning behavior. The strain thinning behavior of the emulsion substantially occurred due to strain thinning behavior of the viscoelastic interfacial layer. The interfacial layer of particles of high concentration provided higher yield stress and shear thinning in the emulsion because it had a higher modulus and rapid thinning behavior compared to a layer of particles of low concentration. Using interfacial rheology, the bulk rheological response of the emulsion could be linked to the mechanical properties of the interfacial layer.
KeywordsInterfacial rheology LAOS Emulsion Clay Montmorillonite Stabilization
This study was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIP) (No. 2016R1E1A1A01942362) as well as (MSIT) (No. NRF-2018R1A5A1024127).
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