printlogo
http://www.ethz.ch/index_EN
Nonmetallic Inorganic Materials
 
print
  

Details

Back to List

Size and Microstructure Control of Calcium Aluminate Microcapsules

Author   Sturzenegger, P. N.; Gonzenbach, U. T.; Martynczuk, J.; Gauckler, L. J.
Year   2012
Type   Journal Article
Journal   Journal of the American Ceramic Society
Volume   95
Issue   8
Pages   2481-2490
Date   Aug
ISSN   0002-7820
Accession Numer   WOS:000307101000019
Abstract   Microencapsulation is nowadays widely applied for the separation or controlled and targeted release of substances. In the present work we propose using particle-stabilized water-in-oil emulsions to produce microcapsules from calcium aluminate cement. First, we investigate the parameters determining the capsule size and size distribution. Then, the anhydrous particles at the water-oil contact line are hydrated resulting in the formation of a layer of precipitated calcium aluminate hydrate that strengthens the capsule shells. By manipulating the hydration reaction of the cement particles, the capsule shell thickness is varied between 200 and 1300 similar to nm. For hydration temperatures of 3 degrees C and 25 degrees C, the capsule walls are mainly formed from Ca2Al2O(5) center dot 8H2O, whereas Ca2Al2O(5) center dot 8H2O and the stable ?-Al(OH)3 and Ca3Al2O6 center dot 6H2O phases are precipitated at 60 degrees C. In addition, the impact of these manipulations on the yield of dry microcapsules is discussed. The highest yield of intact capsules observed in this study is 72 +/- 3%. We believe that such microcapsules can lead to new applications, particularly in environments with harsh conditions or in inorganic matrixes.
Notes   Sturzenegger, Philip N. Gonzenbach, Urs T. Martynczuk, Julia Gauckler, Ludwig J.
Si
URL   Access publication [Website]
Access publication [Website]
Link to PDF  
Record Number   16
Group   nonmet

Back to List

 

Wichtiger Hinweis:
Diese Website wird in älteren Versionen von Netscape ohne graphische Elemente dargestellt. Die Funktionalität der Website ist aber trotzdem gewährleistet. Wenn Sie diese Website regelmässig benutzen, empfehlen wir Ihnen, auf Ihrem Computer einen aktuellen Browser zu installieren. Weitere Informationen finden Sie auf
folgender Seite.

Important Note:
The content in this site is accessible to any browser or Internet device, however, some graphics will display correctly only in the newer versions of Netscape. To get the most out of our site we suggest you upgrade to a newer browser.
More information

© 2019 ETH Zurich | Imprint | Disclaimer | 14 March 2006
top