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Contact-mediated nucleation in melt emulsions investigated by rheo-nuclear magnetic resonance

Kaysan, G. ORCID iD icon; Schork, N.; Herberger, S.; Guthausen, G.; Kind, M.

Abstract:

Increasing the efficiency of disperse phase crystallization is of great interest for melt emulsion production as the fraction of solidified droplets determines product quality and stability. Nucleation events must appear within every single one of the μm-sized droplets for solidification. Therefore, primary crystallization requires high subcooling and is, thus, time and energy consuming. Contact-mediated nucleation is a mechanism for intensifying the crystallization process. It is defined as the successful nucleation of a subcooled liquid droplet induced by contact with an already crystallized droplet. We investigated contact-mediated nucleation under shear flow conditions up to shear rates of 457 s$^{-1}$ for a quantitative assessment of this mechanism. Rheo-nuclear magnetic resonance was successfully used for the time-resolved determination of the solids fraction of the dispersed phase of melt emulsions upon contact-mediated nucleation events. The measurements were carried out in a dedicated Taylor–Couette cell. The efficiency of contact-mediated nucleation $\lambda$$_{sec}$ decreased with increasing shear rate, whereas the effective second order kinetic constant k$_{coll, eff}$ increased approximately linearly at small shear rates and showed a linear decrease for shear rates higher than about 200 s$^{-1}$. ... mehr


Verlagsausgabe §
DOI: 10.5445/IR/1000140720
Originalveröffentlichung
DOI: 10.1002/mrc.5228
Scopus
Zitationen: 6
Web of Science
Zitationen: 7
Dimensions
Zitationen: 6
Cover der Publikation
Zugehörige Institution(en) am KIT Engler-Bunte-Institut (EBI)
Institut für Thermische Verfahrenstechnik (TVT)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2022
Sprache Englisch
Identifikator ISSN: 0749-1581, 0030-4921, 1097-458X
KITopen-ID: 1000140720
Erschienen in Magnetic Resonance in Chemistry
Verlag John Wiley and Sons
Band 60
Heft 7
Seiten 615-627
Vorab online veröffentlicht am 26.10.2021
Nachgewiesen in Dimensions
Scopus
Web of Science
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