Nucleation kinetics during melt crystallization of plant based high oleic and linoleic polyunsaturated fatty acid mixtures
- Nucleation kinetics of high linoleic and high oleic polyunsaturated fatty acid (PUFA) mixtures were investigated during melt crystallization by means of an Focused beam reflectance measurement (FBRM) sensor. Samples were analyzed thermally and chemically in the Differential Scanning Calorimeter (DSC) and Gas Chromatograph (GC) respectively. Investigations showed that a high oleic content in the PUFA mixtures lead to higher induction times, τi. Unlike previous investigations, a clear relation between τi and cooling rates was established. τi increases with increasing cooling rates and decreasing supercooling. Activation energies of nucleation, ∆Gc' were determined by means of the Fisher Turnbull equation wherein ∆Gc' decreases exponentially with increasing supercooling. Investigations and further evaluations conclude that while the plot establishes the effect of supercooling on ∆Gc' , it does not incorporate the effects of molecular diffusion or the cooling rate. Hence, 3D modeling was performed to visualize the combined effects ofNucleation kinetics of high linoleic and high oleic polyunsaturated fatty acid (PUFA) mixtures were investigated during melt crystallization by means of an Focused beam reflectance measurement (FBRM) sensor. Samples were analyzed thermally and chemically in the Differential Scanning Calorimeter (DSC) and Gas Chromatograph (GC) respectively. Investigations showed that a high oleic content in the PUFA mixtures lead to higher induction times, τi. Unlike previous investigations, a clear relation between τi and cooling rates was established. τi increases with increasing cooling rates and decreasing supercooling. Activation energies of nucleation, ∆Gc' were determined by means of the Fisher Turnbull equation wherein ∆Gc' decreases exponentially with increasing supercooling. Investigations and further evaluations conclude that while the plot establishes the effect of supercooling on ∆Gc' , it does not incorporate the effects of molecular diffusion or the cooling rate. Hence, 3D modeling was performed to visualize the combined effects of cooling rate and supercooling on induction time.…
Author: | Sunanda Dasgupta, Florian Rettig, Peter Ay |
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URL: | http://pubs.acs.org/doi/abs/10.1021/acs.cgd.5b01432 |
DOI: | https://doi.org/10.1021/acs.cgd.5b01432 |
ISSN: | 1528-7505 |
Title of the source (English): | Crystal Growth & Design |
Document Type: | Scientific journal article peer-reviewed |
Language: | English |
Year of publication: | 2015 |
Tag: | Melt crystallization, Focused beam reflectance method, Differential Scanning Calorimeter, Fatty Acids, Induction time, Gibbs free enthalpy of crystallization, Fisher Turnbull equation, Supercooling, Activation barrier |
Volume/Year: | 16 |
Issue number: | 2 |
First Page: | 861 |
Last Page: | 866 |
Faculty/Chair: | Fakultät 2 Umwelt und Naturwissenschaften / FG Aufbereitungstechnik und Sekundärrohstofftechnologie (ehemals) |
Institution name at the time of publication: | Fakultät für Umweltwissenschaften und Verfahrenstechnik (eBTU) / LS Aufbereitungstechnik |