Acid-Base Speciation of Carboxylate Ions in the Surface Region of Aqueous Solutions in the Presence of Ammonium and Aminium Ions
Öhrwall, Gunnar LU
; Prisle, Nonne L.
; Ottosson, Niklas
; Werner, Josephina
; Ekholm, Victor
; Walz, Marie-Madeleine
and Bjorneholm, Olle
(2015)
In The Journal of Physical Chemistry Part B
119(10).
p.4033-4040
- Abstract
- The acid base speciation of surface-active carboxylate ions in the surface region of aqueous solutions was studied with synchrotron-radiation-based photoelectron spectroscopy. The protonated form was found at an extraordinarily large fraction compared to that expected from the bulk pH. When adding salts containing the weak acid NH4+ to the solution, the fraction of the acidic form at the surface increases, and to a Much greatet extent than expected from the bulk pH of the solution. We show that ammonium ions also are overrepresented in the surface region, and propose that the interaction between the surface-active anionic carboxylates and cationic ammonium ions creates a carboxylateammonium bilayer close to the surface, which increases the... (More)
- The acid base speciation of surface-active carboxylate ions in the surface region of aqueous solutions was studied with synchrotron-radiation-based photoelectron spectroscopy. The protonated form was found at an extraordinarily large fraction compared to that expected from the bulk pH. When adding salts containing the weak acid NH4+ to the solution, the fraction of the acidic form at the surface increases, and to a Much greatet extent than expected from the bulk pH of the solution. We show that ammonium ions also are overrepresented in the surface region, and propose that the interaction between the surface-active anionic carboxylates and cationic ammonium ions creates a carboxylateammonium bilayer close to the surface, which increases the probability of the protonation of the carboxylae ions. By comparing the situation when a salt of the less volatile amine diethanolatnine is used, We also show that the observed evaporation of ammonia that occurs after such an event only affects the equilibrium marginally. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/5287883
- author
- Öhrwall, Gunnar
LU
; Prisle, Nonne L.
; Ottosson, Niklas
; Werner, Josephina
; Ekholm, Victor
; Walz, Marie-Madeleine
and Bjorneholm, Olle
- organization
- publishing date
- 2015
- type
- Contribution to journal
- publication status
- published
- subject
- in
- The Journal of Physical Chemistry Part B
- volume
- 119
- issue
- 10
- pages
- 4033 - 4040
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- wos:000351188300016
- scopus:84924560323
- pmid:25700136
- ISSN
- 1520-5207
- DOI
- 10.1021/jp509945g
- language
- English
- LU publication?
- yes
- id
- e26a6f4e-cb7c-4c0a-801a-e82cad23b269 (old id 5287883)
- date added to LUP
- 2016-04-01 13:51:54
- date last changed
- 2022-03-21 20:59:00
@article{e26a6f4e-cb7c-4c0a-801a-e82cad23b269,
abstract = {{The acid base speciation of surface-active carboxylate ions in the surface region of aqueous solutions was studied with synchrotron-radiation-based photoelectron spectroscopy. The protonated form was found at an extraordinarily large fraction compared to that expected from the bulk pH. When adding salts containing the weak acid NH4+ to the solution, the fraction of the acidic form at the surface increases, and to a Much greatet extent than expected from the bulk pH of the solution. We show that ammonium ions also are overrepresented in the surface region, and propose that the interaction between the surface-active anionic carboxylates and cationic ammonium ions creates a carboxylateammonium bilayer close to the surface, which increases the probability of the protonation of the carboxylae ions. By comparing the situation when a salt of the less volatile amine diethanolatnine is used, We also show that the observed evaporation of ammonia that occurs after such an event only affects the equilibrium marginally.}},
author = {{Öhrwall, Gunnar and Prisle, Nonne L. and Ottosson, Niklas and Werner, Josephina and Ekholm, Victor and Walz, Marie-Madeleine and Bjorneholm, Olle}},
issn = {{1520-5207}},
language = {{eng}},
number = {{10}},
pages = {{4033--4040}},
publisher = {{The American Chemical Society (ACS)}},
series = {{The Journal of Physical Chemistry Part B}},
title = {{Acid-Base Speciation of Carboxylate Ions in the Surface Region of Aqueous Solutions in the Presence of Ammonium and Aminium Ions}},
url = {{http://dx.doi.org/10.1021/jp509945g}},
doi = {{10.1021/jp509945g}},
volume = {{119}},
year = {{2015}},
}