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Investigation of the surfactant distribution in oil‐in‐water emulsions during the crystallization of the dispersed phase via nuclear magnetic resonance relaxometry and diffusometry
Author(s) -
Kaysan Gina,
Kräling Raphael,
Meier Manuel,
Nirschl Hermann,
Guthausen Gisela,
Kind Matthias
Publication year - 2022
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.5305
Subject(s) - pulmonary surfactant , chemistry , relaxometry , crystallization , micelle , phase (matter) , chemical engineering , diffusion , analytical chemistry (journal) , chemical physics , aqueous solution , chromatography , organic chemistry , spin echo , magnetic resonance imaging , thermodynamics , engineering , radiology , medicine , biochemistry , physics
The crystallization of melt emulsions is of great interest to the food, cosmetic, and pharmaceutical industries. Surfactants are used in emulsions and suspensions to stabilize the dispersed phase; thus, questions arise about the liquid–liquid and solid–liquid interfaces of the droplets or particles and the distribution of the surfactant in the different phases (continuous and dispersed phase, interface). Nuclear magnetic resonance relaxation and diffusion measurements revealed that the internal and rotational mobility of surfactant molecules at the liquid–liquid interface decreases with increasing droplet sizes. Additionally, solid–liquid interfaces have fewer surfactants than liquid–liquid interfaces as a result of the desorption of the surfactant molecules during the crystallization of the droplets. Relaxation rates of surfactant molecules in aqueous solution as single molecules, micelles, and at the liquid–liquid and solid–liquid interface are analyzed for the first time.