Advanced

Phase behavior in the biologically important oleic acid/sodium oleate/water system

Mele, Stefania; Söderman, Olle LU ; Ljusberg-Wahrén, Helena LU ; Thuresson, Krister LU ; Monduzzi, Maura and Nylander, Tommy LU (2018) In Chemistry and Physics of Lipids 211. p.30-36
Abstract

The phase behavior in the oleic acid/sodium oleate/normal saline (0.15 M NaCl aqueous solution) system has been determined. For this purpose visual inspection of samples between crossed polarizers, and Small Angle X-ray diffraction was used to identify the various phases and their unit cell dimensions. A rich phase behavior was observed for the ternary system, featuring reverse micellar, micellar cubic, hexagonal, and cubic phases, and large regions with lamellar phases. As expected the ratio the ‘oleic acid/sodium oleate’ determines the pH and as a consequence the phase behavior. The results could be modeled by an extended Henderson–Hasselbalch (HH) equation, which takes into account the electrostatic potential at the aqueous lipid... (More)

The phase behavior in the oleic acid/sodium oleate/normal saline (0.15 M NaCl aqueous solution) system has been determined. For this purpose visual inspection of samples between crossed polarizers, and Small Angle X-ray diffraction was used to identify the various phases and their unit cell dimensions. A rich phase behavior was observed for the ternary system, featuring reverse micellar, micellar cubic, hexagonal, and cubic phases, and large regions with lamellar phases. As expected the ratio the ‘oleic acid/sodium oleate’ determines the pH and as a consequence the phase behavior. The results could be modeled by an extended Henderson–Hasselbalch (HH) equation, which takes into account the electrostatic potential at the aqueous lipid interface. The knowledge obtained is important for understanding the lipolysis of triglycerides, as the phase behavior of the end-product of the reaction regulates how well the insoluble product can be dispersed and consequently the kinetics of the process.

(Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Degree of dissociation, Fatty acid pKa, Lipolytic enzymes, Liquid crystalline phases, Oleic acid, Small angle X-ray diffraction, Sodium oleate
in
Chemistry and Physics of Lipids
volume
211
pages
7 pages
publisher
Elsevier
external identifiers
  • scopus:85041452495
ISSN
0009-3084
DOI
10.1016/j.chemphyslip.2017.11.017
language
English
LU publication?
yes
id
497e6a6c-c94c-45de-8fcd-bc5ec989b10d
date added to LUP
2018-03-28 09:44:01
date last changed
2019-03-19 03:51:57
@article{497e6a6c-c94c-45de-8fcd-bc5ec989b10d,
  abstract     = {<p>The phase behavior in the oleic acid/sodium oleate/normal saline (0.15 M NaCl aqueous solution) system has been determined. For this purpose visual inspection of samples between crossed polarizers, and Small Angle X-ray diffraction was used to identify the various phases and their unit cell dimensions. A rich phase behavior was observed for the ternary system, featuring reverse micellar, micellar cubic, hexagonal, and cubic phases, and large regions with lamellar phases. As expected the ratio the ‘oleic acid/sodium oleate’ determines the pH and as a consequence the phase behavior. The results could be modeled by an extended Henderson–Hasselbalch (HH) equation, which takes into account the electrostatic potential at the aqueous lipid interface. The knowledge obtained is important for understanding the lipolysis of triglycerides, as the phase behavior of the end-product of the reaction regulates how well the insoluble product can be dispersed and consequently the kinetics of the process.</p>},
  author       = {Mele, Stefania and Söderman, Olle and Ljusberg-Wahrén, Helena and Thuresson, Krister and Monduzzi, Maura and Nylander, Tommy},
  issn         = {0009-3084},
  keyword      = {Degree of dissociation,Fatty acid pKa,Lipolytic enzymes,Liquid crystalline phases,Oleic acid,Small angle X-ray diffraction,Sodium oleate},
  language     = {eng},
  month        = {03},
  pages        = {30--36},
  publisher    = {Elsevier},
  series       = {Chemistry and Physics of Lipids},
  title        = {Phase behavior in the biologically important oleic acid/sodium oleate/water system},
  url          = {http://dx.doi.org/10.1016/j.chemphyslip.2017.11.017},
  volume       = {211},
  year         = {2018},
}