Eguchi, Kazuya, Niether, Doreen ORCID: 0000-0002-8496-4215, Wiegand, Simone
ORCID: 0000-0001-6333-1956 and Kita, Rio
ORCID: 0000-0002-9683-5840
(2016).
Thermophoresis of cyclic oligosaccharides in polar solvents.
Eur. Phys. J. E, 39 (9).
NEW YORK:
SPRINGER.
ISSN 1292-895X
Abstract
Cyclodextrins are cyclic oligosaccharides which are interesting as drug delivery systems, because they can be used as containers for pharmaceutical substances. We studied the Ludwig-Soret effect of alpha-, beta-, gamma- and methyl-beta-cyclodextrin in water and formamide by infrared thermal diffusion forced Rayleigh scattering (IR-TDFRS). In water the Soret coefficient, S-T, of alpha-, beta- and gamma-cyclodextrin increases with increasing temperature and shows a sign change from negative to positive around T = 35 degrees C, while S-T of methyl-beta-cyclodextrin is positive in the entire investigated temperature. In formamide S-T-values of all cyclodextrins coincide and show a slight decrease with temperature. We discuss the obtained results and relate the S-T-values to the different hydrogen bonding capabilities of the cyclodextrins and the used solvents. It turns out that the change of S-T with temperature correlates with the partition coefficient, log P, which indicates that more hydrophilic substances show a more pronounced temperature sensitivity of S-T. Additionally we obtained a surprising result measuring the refractive index contrast factor with temperature, (partial derivative n/partial derivative T)(c,p) of cyclodextrins in formamide, which might be explained by a complex formation between cyclodextrins and formamide.
Item Type: | Journal Article | ||||||||||||||||||||
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URN: | urn:nbn:de:hbz:38-262042 | ||||||||||||||||||||
DOI: | 10.1140/epje/i2016-16086-5 | ||||||||||||||||||||
Journal or Publication Title: | Eur. Phys. J. E | ||||||||||||||||||||
Volume: | 39 | ||||||||||||||||||||
Number: | 9 | ||||||||||||||||||||
Date: | 2016 | ||||||||||||||||||||
Publisher: | SPRINGER | ||||||||||||||||||||
Place of Publication: | NEW YORK | ||||||||||||||||||||
ISSN: | 1292-895X | ||||||||||||||||||||
Language: | English | ||||||||||||||||||||
Faculty: | Faculty of Mathematics and Natural Sciences | ||||||||||||||||||||
Divisions: | Faculty of Mathematics and Natural Sciences > Department of Chemistry > Institute of Physical Chemistry | ||||||||||||||||||||
Subjects: | no entry | ||||||||||||||||||||
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Refereed: | Yes | ||||||||||||||||||||
URI: | http://kups.ub.uni-koeln.de/id/eprint/26204 |
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