Driving forces of phase transitions in surfactant and lipid systems
(2005) In The Journal of Physical Chemistry Part B 109(13). p.6430-6435- Abstract
- In aqueous surfactant and lipid systems, different liquid crystalline phases are formed at different temperatures and water contents. The "natural" phase sequence implies that phases with higher curvature are formed at higher water contents. On the other hand, there are exceptions to this rule, such as the monoolein/water system. In this system an anomalous transition from lamellar to reverse cubic phase upon addition of water is observed. The calorimetric data presented here show that the hydration-induced transitions to phases with higher curvature are driven by enthalpy, while the transitions to phases with lower curvature are driven by entropy. It is shown that the driving forces of phase transitions can be determined from the... (More)
- In aqueous surfactant and lipid systems, different liquid crystalline phases are formed at different temperatures and water contents. The "natural" phase sequence implies that phases with higher curvature are formed at higher water contents. On the other hand, there are exceptions to this rule, such as the monoolein/water system. In this system an anomalous transition from lamellar to reverse cubic phase upon addition of water is observed. The calorimetric data presented here show that the hydration-induced transitions to phases with higher curvature are driven by enthalpy, while the transitions to phases with lower curvature are driven by entropy. It is shown that the driving forces of phase transitions can be determined from the appearance of the phase diagram using the approach based on van der Waals differential equation. From this approach it follows that the slope of the phase boundary should be positive with respect to water content if the phase diagram obeys the "natural" phase sequence. The increase of entropy, which drives the anomalous phase transitions, arises from the increase of disorder of the hydrocarbon chains. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/157425
- author
- Kocherbitov, Vitaly LU
- organization
- publishing date
- 2005
- type
- Contribution to journal
- publication status
- published
- subject
- in
- The Journal of Physical Chemistry Part B
- volume
- 109
- issue
- 13
- pages
- 6430 - 6435
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- wos:000228111200056
- scopus:17044368359
- pmid:16851716
- ISSN
- 1520-5207
- DOI
- 10.1021/jp045555l
- language
- English
- LU publication?
- yes
- id
- 21b79279-5a47-4a25-b028-614836e419f9 (old id 157425)
- date added to LUP
- 2016-04-01 16:29:06
- date last changed
- 2022-01-28 20:01:25
@article{21b79279-5a47-4a25-b028-614836e419f9,
abstract = {{In aqueous surfactant and lipid systems, different liquid crystalline phases are formed at different temperatures and water contents. The "natural" phase sequence implies that phases with higher curvature are formed at higher water contents. On the other hand, there are exceptions to this rule, such as the monoolein/water system. In this system an anomalous transition from lamellar to reverse cubic phase upon addition of water is observed. The calorimetric data presented here show that the hydration-induced transitions to phases with higher curvature are driven by enthalpy, while the transitions to phases with lower curvature are driven by entropy. It is shown that the driving forces of phase transitions can be determined from the appearance of the phase diagram using the approach based on van der Waals differential equation. From this approach it follows that the slope of the phase boundary should be positive with respect to water content if the phase diagram obeys the "natural" phase sequence. The increase of entropy, which drives the anomalous phase transitions, arises from the increase of disorder of the hydrocarbon chains.}},
author = {{Kocherbitov, Vitaly}},
issn = {{1520-5207}},
language = {{eng}},
number = {{13}},
pages = {{6430--6435}},
publisher = {{The American Chemical Society (ACS)}},
series = {{The Journal of Physical Chemistry Part B}},
title = {{Driving forces of phase transitions in surfactant and lipid systems}},
url = {{http://dx.doi.org/10.1021/jp045555l}},
doi = {{10.1021/jp045555l}},
volume = {{109}},
year = {{2005}},
}