Simulation of phase equilibria in lamellar surfactant systems
(2004) In Langmuir 20(12). p.5123-5126- Abstract
- The coexistence of two lamellar liquid crystalline phases has been investigated by means of Monte Carlo simulations. The surfaces of the negatively charged bilayers formed by the surfactant molecules are modeled as planar infinite walls with a uniform surface charge density. Water is treated as a dielectric continuum, and only electrostatic interactions are considered. The counterions are mono- and divalent point ions, and their ratio is allowed to vary. Monovalent counterions lead to a repulsive osmotic pressure at all separations, while an attractive region exists when the counterions are divalent. In the latter case, one would expect a phase separation to take place, although it is not observed experimentally due to the limited... (More)
- The coexistence of two lamellar liquid crystalline phases has been investigated by means of Monte Carlo simulations. The surfaces of the negatively charged bilayers formed by the surfactant molecules are modeled as planar infinite walls with a uniform surface charge density. Water is treated as a dielectric continuum, and only electrostatic interactions are considered. The counterions are mono- and divalent point ions, and their ratio is allowed to vary. Monovalent counterions lead to a repulsive osmotic pressure at all separations, while an attractive region exists when the counterions are divalent. In the latter case, one would expect a phase separation to take place, although it is not observed experimentally due to the limited stability of the lamellar phase at high water content. In a system with mixed counterions, however, the osmotic pressure exhibits a van der Waals loop under such conditions that two phases can coexist. A phase diagram is constructed, and the agreement with experimental data is excellent. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/139657
- author
- Turesson, Martin LU ; Forsman, Jan LU ; Åkesson, Torbjörn LU and Jönsson, Bo LU
- organization
- publishing date
- 2004
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Langmuir
- volume
- 20
- issue
- 12
- pages
- 5123 - 5126
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- wos:000221846000050
- pmid:15984278
- scopus:2942733694
- ISSN
- 0743-7463
- DOI
- 10.1021/la049858i
- language
- English
- LU publication?
- yes
- additional info
- The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Theoretical Chemistry (S) (011001039)
- id
- 2e391ff9-d135-432b-8109-3bc2a3c286b9 (old id 139657)
- date added to LUP
- 2016-04-01 11:57:06
- date last changed
- 2023-01-03 01:42:39
@article{2e391ff9-d135-432b-8109-3bc2a3c286b9,
abstract = {{The coexistence of two lamellar liquid crystalline phases has been investigated by means of Monte Carlo simulations. The surfaces of the negatively charged bilayers formed by the surfactant molecules are modeled as planar infinite walls with a uniform surface charge density. Water is treated as a dielectric continuum, and only electrostatic interactions are considered. The counterions are mono- and divalent point ions, and their ratio is allowed to vary. Monovalent counterions lead to a repulsive osmotic pressure at all separations, while an attractive region exists when the counterions are divalent. In the latter case, one would expect a phase separation to take place, although it is not observed experimentally due to the limited stability of the lamellar phase at high water content. In a system with mixed counterions, however, the osmotic pressure exhibits a van der Waals loop under such conditions that two phases can coexist. A phase diagram is constructed, and the agreement with experimental data is excellent.}},
author = {{Turesson, Martin and Forsman, Jan and Åkesson, Torbjörn and Jönsson, Bo}},
issn = {{0743-7463}},
language = {{eng}},
number = {{12}},
pages = {{5123--5126}},
publisher = {{The American Chemical Society (ACS)}},
series = {{Langmuir}},
title = {{Simulation of phase equilibria in lamellar surfactant systems}},
url = {{http://dx.doi.org/10.1021/la049858i}},
doi = {{10.1021/la049858i}},
volume = {{20}},
year = {{2004}},
}