Bioucas F, Koller TM, Fröba AP (2023)
Publication Language: English
Publication Type: Journal article, Original article
Publication year: 2023
Book Volume: 200
Article Number: 123526
DOI: 10.1016/j.ijheatmasstransfer.2022.123526
Microemulsions consist of a liquid dispersion medium and a dispersed phase of colloidal liquid micelles in the nanometer scale. Despite its technological relevance, the effective thermal conductivity of microemulsions has scarcely been investigated both experimentally and theoretically. To elucidate the influence of the concentration of the dispersed micelles and their morphology on the effective thermal conductivity of reverse microemulsions consisting of a n-decane-rich continuous phase and a dispersed surfactant-stabilized phase with water-free or water-swollen micelles, a steady-state parallel-plate instrument was used between 298 and 318 K at water volume fractions from 0 to 0.47. The measured effective thermal conductivities increase with increasing volume fraction of the dispersed water micelles, which is by trend accompanied by increasing effective viscosities and decreasing translational particle diffusion coefficients, as obtained by capillary viscometry and dynamic light scattering. The Hamilton-Crosser model and an analytical thermal-resistance model, which are often employed for dispersions of solid particles in liquids, describe the effective thermal conductivity of microemulsions well in case of virtually spherical micelles at low water loading. Distinct underestimations by both models assuming spherical particles appear at higher water contents and temperatures beyond the percolation at about 308 K, associated with micelle clusters up to a bicontinuous microemulsion structure. Especially for these states, it could be found that the effective thermal conductivity can be well represented by the average of a serial and a parallel resistance model for thermal conduction.
APA:
Bioucas, F., Koller, T.M., & Fröba, A.P. (2023). Effective thermal conductivity of microemulsions consisting of water micelles in n‐decane. International Journal of Heat and Mass Transfer, 200. https://dx.doi.org/10.1016/j.ijheatmasstransfer.2022.123526
MLA:
Bioucas, Francisco, Thomas Manfred Koller, and Andreas Paul Fröba. "Effective thermal conductivity of microemulsions consisting of water micelles in n‐decane." International Journal of Heat and Mass Transfer 200 (2023).
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