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Gels of hydrophobically modified ethyl (hydroxyethyl) cellulose cross-linked by amylose: Effects of hydrophobe architecture

Egermayer, Monica LU ; Karlberg, Maria LU and Piculell, Lennart LU (2004) In Langmuir 20(6). p.2208-2214
Abstract
Previous work has shown that amylose (AM) can cross-link hydrophobically modified polymers by inclusion complexation, whereby thermoreversible cold-setting gels are formed. Here we investigate the complexation of AM with different samples of hydrophobically modified ethyl(hydroxyethyl) cellulose (HMEHEC), distinguished by differences in the architecture of the hydrophobes (the hydrophobic side chains). All hydrophobes, except one, were based on linear alkyl chains, but with varying chain lengths (C-12-C-14). In addition, some samples contained short hydrophilic "spacers", consisting of 2-5 ethylene oxide units, between the alkyl chains and the EHEC backbone. Gels of varying strength were obtained for the different AM/HMEHEC samples. The... (More)
Previous work has shown that amylose (AM) can cross-link hydrophobically modified polymers by inclusion complexation, whereby thermoreversible cold-setting gels are formed. Here we investigate the complexation of AM with different samples of hydrophobically modified ethyl(hydroxyethyl) cellulose (HMEHEC), distinguished by differences in the architecture of the hydrophobes (the hydrophobic side chains). All hydrophobes, except one, were based on linear alkyl chains, but with varying chain lengths (C-12-C-14). In addition, some samples contained short hydrophilic "spacers", consisting of 2-5 ethylene oxide units, between the alkyl chains and the EHEC backbone. Gels of varying strength were obtained for the different AM/HMEHEC samples. The alkyl chain length seemed to be the major factor affecting the gel strength, with longer alkyl chains giving stronger gels. For similar alkyl chain lengths, stronger gels were obtained when a spacer was present. Addition of AM caused a small increase of the cloud points of HMEHECs with C-14 hydrophobes in water. Time-dependent effects and effects of the sample preparation procedure were also investigated. The reversibility of the gelation with respect to shear was confirmed. A gel destroyed by added surfactant was shown to reform on removal of the surfactant by dialysis. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Langmuir
volume
20
issue
6
pages
2208 - 2214
publisher
The American Chemical Society
external identifiers
  • wos:000220159800027
  • pmid:15835672
  • scopus:1842425621
ISSN
0743-7463
DOI
10.1021/la036053m
language
English
LU publication?
yes
id
dbeea1c1-026e-4ee0-bb4e-e6dbee9d21fb (old id 153855)
date added to LUP
2007-07-11 10:59:02
date last changed
2017-01-01 04:43:43
@article{dbeea1c1-026e-4ee0-bb4e-e6dbee9d21fb,
  abstract     = {Previous work has shown that amylose (AM) can cross-link hydrophobically modified polymers by inclusion complexation, whereby thermoreversible cold-setting gels are formed. Here we investigate the complexation of AM with different samples of hydrophobically modified ethyl(hydroxyethyl) cellulose (HMEHEC), distinguished by differences in the architecture of the hydrophobes (the hydrophobic side chains). All hydrophobes, except one, were based on linear alkyl chains, but with varying chain lengths (C-12-C-14). In addition, some samples contained short hydrophilic "spacers", consisting of 2-5 ethylene oxide units, between the alkyl chains and the EHEC backbone. Gels of varying strength were obtained for the different AM/HMEHEC samples. The alkyl chain length seemed to be the major factor affecting the gel strength, with longer alkyl chains giving stronger gels. For similar alkyl chain lengths, stronger gels were obtained when a spacer was present. Addition of AM caused a small increase of the cloud points of HMEHECs with C-14 hydrophobes in water. Time-dependent effects and effects of the sample preparation procedure were also investigated. The reversibility of the gelation with respect to shear was confirmed. A gel destroyed by added surfactant was shown to reform on removal of the surfactant by dialysis.},
  author       = {Egermayer, Monica and Karlberg, Maria and Piculell, Lennart},
  issn         = {0743-7463},
  language     = {eng},
  number       = {6},
  pages        = {2208--2214},
  publisher    = {The American Chemical Society},
  series       = {Langmuir},
  title        = {Gels of hydrophobically modified ethyl (hydroxyethyl) cellulose cross-linked by amylose: Effects of hydrophobe architecture},
  url          = {http://dx.doi.org/10.1021/la036053m},
  volume       = {20},
  year         = {2004},
}