Details
| Original language | English |
|---|---|
| Pages (from-to) | 929-938 |
| Number of pages | 10 |
| Journal | Heat and Mass Transfer/Waerme- und Stoffuebertragung |
| Volume | 42 |
| Issue number | 10 |
| Early online date | 28 Jun 2006 |
| Publication status | Published - Aug 2006 |
Abstract
The potential of a high electric field was utilized to induce ice nucleus formation in aqueous solutions. Using this technique it was possible to reduce the primary drying time during lyophilization. Samples of 10% (w/v) hydroxyethylstarch (HES) solution were frozen at a constant rate of -1 K/min, while nucleation was initiated at temperatures of -1.5, -4.5 and -8.5°C. In contrast, spontaneous nucleation was observed in a range between -11.5 and -17.1°C. Electrically induced nucleus formation has proved to be a reliable method to start crystallization at a desired temperature. Continuous measurement of the weight allowed to determine the drying rate and to detect at which time primary drying was completed. The drying time and the drying rate were found to be strongly dependent on the nucleation temperature during freezing. A relation between the nucleation temperature, the structure of the frozen samples and the drying times could be established.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Condensed Matter Physics
- Chemical Engineering(all)
- Fluid Flow and Transfer Processes
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In: Heat and Mass Transfer/Waerme- und Stoffuebertragung, Vol. 42, No. 10, 08.2006, p. 929-938.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Reduction of primary freeze-drying time by electric field induced ice nucleus formation
AU - Petersen, Ansgar
AU - Rau, Guenter
AU - Glasmacher, Birgit
PY - 2006/8
Y1 - 2006/8
N2 - The potential of a high electric field was utilized to induce ice nucleus formation in aqueous solutions. Using this technique it was possible to reduce the primary drying time during lyophilization. Samples of 10% (w/v) hydroxyethylstarch (HES) solution were frozen at a constant rate of -1 K/min, while nucleation was initiated at temperatures of -1.5, -4.5 and -8.5°C. In contrast, spontaneous nucleation was observed in a range between -11.5 and -17.1°C. Electrically induced nucleus formation has proved to be a reliable method to start crystallization at a desired temperature. Continuous measurement of the weight allowed to determine the drying rate and to detect at which time primary drying was completed. The drying time and the drying rate were found to be strongly dependent on the nucleation temperature during freezing. A relation between the nucleation temperature, the structure of the frozen samples and the drying times could be established.
AB - The potential of a high electric field was utilized to induce ice nucleus formation in aqueous solutions. Using this technique it was possible to reduce the primary drying time during lyophilization. Samples of 10% (w/v) hydroxyethylstarch (HES) solution were frozen at a constant rate of -1 K/min, while nucleation was initiated at temperatures of -1.5, -4.5 and -8.5°C. In contrast, spontaneous nucleation was observed in a range between -11.5 and -17.1°C. Electrically induced nucleus formation has proved to be a reliable method to start crystallization at a desired temperature. Continuous measurement of the weight allowed to determine the drying rate and to detect at which time primary drying was completed. The drying time and the drying rate were found to be strongly dependent on the nucleation temperature during freezing. A relation between the nucleation temperature, the structure of the frozen samples and the drying times could be established.
UR - http://www.scopus.com/inward/record.url?scp=33745698119&partnerID=8YFLogxK
U2 - 10.1007/s00231-006-0153-3
DO - 10.1007/s00231-006-0153-3
M3 - Article
AN - SCOPUS:33745698119
VL - 42
SP - 929
EP - 938
JO - Heat and Mass Transfer/Waerme- und Stoffuebertragung
JF - Heat and Mass Transfer/Waerme- und Stoffuebertragung
SN - 0947-7411
IS - 10
ER -