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DOE OSTI · 2203487

Temperature-dependent complex dielectric permittivity: a simple measurement strategy for liquid-phase samples

Baker-Fales, Montgomery·Gutiérrez-Cano, José D.·Catalá-Civera, José M.·Vlachos, Dionisios G.
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Abstract

Abstract Microwaves (MWs) are an emerging technology for intensified and electrified chemical manufacturing. MW heating is intimately linked to a material’s dielectric permittivity. These properties are highly dependent on temperature and pressure, but such datasets are not readily available due to the limited accessibility of the current methodologies to process-oriented laboratories. We introduce a simple, benchtop approach for producing these datasets near the 2.45 GHz industrial, medical, and scientific (ISM) frequency for liquid samples. By building upon a previously-demonstrated bireentrant microwave measurement cavity, we introduce larger pressure- and temperature-capable vials to deduce temperature-dependent permittivity quickly and accurately for vapor pressures up to 7 bar. Our methodology is validated using literature data, demonstrating broad applicability for materials with dielectric constant ε' ranging from 1 to 100. We provide new permittivity data for water, organic solvents, and hydrochloric acid solutions. Finally, we provide simple fits to our data for easy use.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRYanalytical techniqueschemical engineering

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Baker-Fales, Montgomery, Gutiérrez-Cano, José D., Catalá-Civera, José M., Vlachos, Dionisios G.. 2023-10-24. Temperature-dependent complex dielectric permittivity: a simple measurement strategy for liquid-phase samples. https://doi.org/10.1038/s41598-023-45049-8

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