Thermal control over the electrophoresis of soft colloidal particles
We study the electrophoresis of surface-charged thermosensitive microgel particles based on poly-N-isopropylacrylamide (PNIPAM); these deswell with increasing temperature T. Our results show that the electrophoretic mobility mu is affected by the temperature-induced volume phase transition. It incre...
Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1992. - 22(2006), 8 vom: 11. Apr., Seite 3586-90 |
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Weitere Verfasser: | , , |
Format: | Aufsatz |
Sprache: | English |
Veröffentlicht: |
2006
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Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
Schlagworte: | Journal Article |
Zusammenfassung: | We study the electrophoresis of surface-charged thermosensitive microgel particles based on poly-N-isopropylacrylamide (PNIPAM); these deswell with increasing temperature T. Our results show that the electrophoretic mobility mu is affected by the temperature-induced volume phase transition. It increases with increasing temperature, as a result of the charge density increase induced by particle deswelling. Temperature thus allows control of mu, in contrast to the more conventional charged hard spheres for which mu is T independent. Salt also affects the mu behavior and gives rise to rich phenomenology, sharing common characteristics with charged hard spheres and polyelectrolyte-coated colloids depending on whether the microgels are swollen or deswollen. We interpret the effects of salt concentration n by considering that particle charges are located in an external shell, as confirmed by titrations, and that it is this shell-salt-induced compression that affects the resulting mu behavior |
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Beschreibung: | Date Completed 09.07.2007 Date Revised 04.04.2006 published: Print Citation Status PubMed-not-MEDLINE |
ISSN: | 1520-5827 |