Advanced

Phase equilibria of the mixed didodecyldimethylammonium bromide-sodium taurodeoxycholate-water system with a large solution region

Sjöbom, M B; Marques, E F; Edlund, H and Khan, Ali LU (2005) In Colloids and Surfaces A: Physicochemical and Engineering Aspects 269(1-3). p.87-95
Abstract
The phase behavior over the entire concentration range for the system didodecyldimethylammonium bromide (DDAB)-sodium taurodeoxycholate (STDC)-water, at 25 degrees C, has been investigated, with emphasis on the DDAB-rich part. Polarizing microscopy, SAXS, H-2 NMR and H-1 self-diffusion NMR have been used in combination as probing techniques for phase behavior and microstructure. The system forms four major phases, all deriving from the respective binary surfactant systems. The two lamellar phases originating from the binary DDAB-water axis (D-I and D-II, at 3-30 and 83-91 wt.% DDAB, respectively) are only able to incorporate small amounts of STDC. The D-II phase solubilizes a comparatively higher amount of bile salt (up to ca. 6 wt.%),... (More)
The phase behavior over the entire concentration range for the system didodecyldimethylammonium bromide (DDAB)-sodium taurodeoxycholate (STDC)-water, at 25 degrees C, has been investigated, with emphasis on the DDAB-rich part. Polarizing microscopy, SAXS, H-2 NMR and H-1 self-diffusion NMR have been used in combination as probing techniques for phase behavior and microstructure. The system forms four major phases, all deriving from the respective binary surfactant systems. The two lamellar phases originating from the binary DDAB-water axis (D-I and D-II, at 3-30 and 83-91 wt.% DDAB, respectively) are only able to incorporate small amounts of STDC. The D-II phase solubilizes a comparatively higher amount of bile salt (up to ca. 6 wt.%), while the D, phase takes up less than 0.25 wt.%. From the STDC-water axis, a solution phase and a "hexagonal-like" liquid crystalline phase are derived, at 0-26 and 37-60 wt.% of STDC, respectively. Heterogeneous regions are also indicated on the basis of NMR and SAXS data. The most striking feature is the large extension of the isotropic solution phase, which originates from the water corner and curves toward the DDAB-rich side of the phase diagram. Even though at the upper limit of the solution phase the amount of water is reduced to 10 wt.%, the measured water and DDAB self-diffusion coefficients exclude the possibility of reverse-type structures. (c) 2005 Elsevier B.V. All rights reserved. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Colloids and Surfaces A: Physicochemical and Engineering Aspects
volume
269
issue
1-3
pages
87 - 95
publisher
Elsevier
external identifiers
  • wos:000233262200012
  • scopus:27244447395
ISSN
0927-7757
DOI
10.1016/j.colsurfa.2005.06.066
language
English
LU publication?
yes
id
00a98ffd-edaf-4960-99e4-5809f6653ffd (old id 157590)
date added to LUP
2007-07-12 11:36:13
date last changed
2017-09-10 04:39:34
@article{00a98ffd-edaf-4960-99e4-5809f6653ffd,
  abstract     = {The phase behavior over the entire concentration range for the system didodecyldimethylammonium bromide (DDAB)-sodium taurodeoxycholate (STDC)-water, at 25 degrees C, has been investigated, with emphasis on the DDAB-rich part. Polarizing microscopy, SAXS, H-2 NMR and H-1 self-diffusion NMR have been used in combination as probing techniques for phase behavior and microstructure. The system forms four major phases, all deriving from the respective binary surfactant systems. The two lamellar phases originating from the binary DDAB-water axis (D-I and D-II, at 3-30 and 83-91 wt.% DDAB, respectively) are only able to incorporate small amounts of STDC. The D-II phase solubilizes a comparatively higher amount of bile salt (up to ca. 6 wt.%), while the D, phase takes up less than 0.25 wt.%. From the STDC-water axis, a solution phase and a "hexagonal-like" liquid crystalline phase are derived, at 0-26 and 37-60 wt.% of STDC, respectively. Heterogeneous regions are also indicated on the basis of NMR and SAXS data. The most striking feature is the large extension of the isotropic solution phase, which originates from the water corner and curves toward the DDAB-rich side of the phase diagram. Even though at the upper limit of the solution phase the amount of water is reduced to 10 wt.%, the measured water and DDAB self-diffusion coefficients exclude the possibility of reverse-type structures. (c) 2005 Elsevier B.V. All rights reserved.},
  author       = {Sjöbom, M B and Marques, E F and Edlund, H and Khan, Ali},
  issn         = {0927-7757},
  language     = {eng},
  number       = {1-3},
  pages        = {87--95},
  publisher    = {Elsevier},
  series       = {Colloids and Surfaces A: Physicochemical and Engineering Aspects},
  title        = {Phase equilibria of the mixed didodecyldimethylammonium bromide-sodium taurodeoxycholate-water system with a large solution region},
  url          = {http://dx.doi.org/10.1016/j.colsurfa.2005.06.066},
  volume       = {269},
  year         = {2005},
}