Potential Determining Salts in Microemulsions: Interfacial Distribution and Effect on the Phase Behavior
(2013) In Langmuir 29(51). p.15738-15746- Abstract
- In this work we consider potential determining salts, also referred to as phase transfer agents for a future objective of electrochemistry at the oil-water interface in microemulsions. We have studied these salts, composed of a hydrophilic and a hydrophobic ion, in microemulsion stabilized by nonionic surfactants with an oligo ethylene oxide headgroup. NMR measurements show that the salts preferentially dissociate across the surfactant interface between the oil and water domains, and hence create a potential drop across the surfactant film, and back to back diffuse double layers in the oil and water phases. These observations are also supported by Poisson-Boltzmann calculations. This adsorption like event stabilizes the microemulsion.... (More)
- In this work we consider potential determining salts, also referred to as phase transfer agents for a future objective of electrochemistry at the oil-water interface in microemulsions. We have studied these salts, composed of a hydrophilic and a hydrophobic ion, in microemulsion stabilized by nonionic surfactants with an oligo ethylene oxide headgroup. NMR measurements show that the salts preferentially dissociate across the surfactant interface between the oil and water domains, and hence create a potential drop across the surfactant film, and back to back diffuse double layers in the oil and water phases. These observations are also supported by Poisson-Boltzmann calculations. This adsorption like event stabilizes the microemulsion. Repulsive long-range interactions between thin lamellae of surfactant and water lamellae in oil were observed using SAXS, thus confirming the presence of electrostatic forces mediated through the oil domain. We also observed that reversing the charges on the potential determining salts had opposite effects on the phase inversion temperature. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/4255930
- author
- Johans, Christoffer ; Behrens, Manja LU ; Bergquist, Karl-Erik LU ; Olsson, Ulf LU and Manzanares, Jose A.
- organization
- publishing date
- 2013
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Langmuir
- volume
- 29
- issue
- 51
- pages
- 15738 - 15746
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- wos:000329137000003
- scopus:84896536156
- ISSN
- 0743-7463
- DOI
- 10.1021/la404263v
- language
- English
- LU publication?
- yes
- id
- 48b4c9c9-2a28-4059-ba60-20bbddf67f75 (old id 4255930)
- date added to LUP
- 2016-04-01 10:46:23
- date last changed
- 2022-04-04 21:12:26
@article{48b4c9c9-2a28-4059-ba60-20bbddf67f75,
abstract = {{In this work we consider potential determining salts, also referred to as phase transfer agents for a future objective of electrochemistry at the oil-water interface in microemulsions. We have studied these salts, composed of a hydrophilic and a hydrophobic ion, in microemulsion stabilized by nonionic surfactants with an oligo ethylene oxide headgroup. NMR measurements show that the salts preferentially dissociate across the surfactant interface between the oil and water domains, and hence create a potential drop across the surfactant film, and back to back diffuse double layers in the oil and water phases. These observations are also supported by Poisson-Boltzmann calculations. This adsorption like event stabilizes the microemulsion. Repulsive long-range interactions between thin lamellae of surfactant and water lamellae in oil were observed using SAXS, thus confirming the presence of electrostatic forces mediated through the oil domain. We also observed that reversing the charges on the potential determining salts had opposite effects on the phase inversion temperature.}},
author = {{Johans, Christoffer and Behrens, Manja and Bergquist, Karl-Erik and Olsson, Ulf and Manzanares, Jose A.}},
issn = {{0743-7463}},
language = {{eng}},
number = {{51}},
pages = {{15738--15746}},
publisher = {{The American Chemical Society (ACS)}},
series = {{Langmuir}},
title = {{Potential Determining Salts in Microemulsions: Interfacial Distribution and Effect on the Phase Behavior}},
url = {{http://dx.doi.org/10.1021/la404263v}},
doi = {{10.1021/la404263v}},
volume = {{29}},
year = {{2013}},
}