Multiple thin film formation from dilute mixtures of polyethyleneimine (PEI) and cetyltrimethylammonium bromide (CTAB)
Comas-Rojas, H. ; Fernández-Catá, G. ; Edler, K. J. LU
; Roser, S. J.
and Pérez-Gramatges, A.
(2009)
In Journal of Colloid and Interface Science
339(2).
p.495-501
- Abstract
Dilute mixtures of the water soluble polymer polyethyleneimine (PEI) and the cationic surfactant cetyltrimethylammonium bromide (CTAB) form mesostructured thin films at the air/solution interface. In this paper we show that these films form spontaneously, reaching an equilibrium composition. When the film is removed, a new solid film rapidly reforms, with a similar morphology when inspected by Brewster angle microscopy (BAM). Successive removal of films lead to a series of structurally similar films, until the amount of surfactant in solution approaches the lower limit of film forming concentration. The results obtained using surfactant-selective potentiometry suggest that the incipient polymer:surfactant aggregates are in a position to... (More)
Dilute mixtures of the water soluble polymer polyethyleneimine (PEI) and the cationic surfactant cetyltrimethylammonium bromide (CTAB) form mesostructured thin films at the air/solution interface. In this paper we show that these films form spontaneously, reaching an equilibrium composition. When the film is removed, a new solid film rapidly reforms, with a similar morphology when inspected by Brewster angle microscopy (BAM). Successive removal of films lead to a series of structurally similar films, until the amount of surfactant in solution approaches the lower limit of film forming concentration. The results obtained using surfactant-selective potentiometry suggest that the incipient polymer:surfactant aggregates are in a position to migrate to the surface rapidly after film removal, prior to mesostructure formation. X-ray reflectivity indicates that films formed at different PEI:CTAB compositions retain mesophase regular structures with the same d-spacing feature, equal to 52.2 Å. Grazing incidence diffraction measurements indicate that films are composed of small crystallites arranged in a random powder fashion, developing a rough surface morphology evidenced by BAM. The central finding is that PEI:CTAB films form when the amount of CTAB in solution is higher than a critical film formation concentration, very close to the critical aggregation concentration (CAC), allowing the formation of several equilibrated films from the same growing solution.
(Less)
- author
- Comas-Rojas, H.
; Fernández-Catá, G.
; Edler, K. J.
LU
; Roser, S. J.
and Pérez-Gramatges, A.
- publishing date
- 2009-11-15
- type
- Contribution to journal
- publication status
- published
- keywords
- CTAB, PEI, Potentiometry, Reflectometry, Surfactant, Thin films
- in
- Journal of Colloid and Interface Science
- volume
- 339
- issue
- 2
- pages
- 7 pages
- publisher
- Elsevier
- external identifiers
-
- scopus:70349466521
- ISSN
- 0021-9797
- DOI
- 10.1016/j.jcis.2009.07.067
- language
- English
- LU publication?
- no
- id
- a2761f1e-835d-4b48-945c-620b2c397dee
- date added to LUP
- 2023-05-04 18:18:35
- date last changed
- 2023-06-09 15:02:32
@article{a2761f1e-835d-4b48-945c-620b2c397dee,
abstract = {{<p>Dilute mixtures of the water soluble polymer polyethyleneimine (PEI) and the cationic surfactant cetyltrimethylammonium bromide (CTAB) form mesostructured thin films at the air/solution interface. In this paper we show that these films form spontaneously, reaching an equilibrium composition. When the film is removed, a new solid film rapidly reforms, with a similar morphology when inspected by Brewster angle microscopy (BAM). Successive removal of films lead to a series of structurally similar films, until the amount of surfactant in solution approaches the lower limit of film forming concentration. The results obtained using surfactant-selective potentiometry suggest that the incipient polymer:surfactant aggregates are in a position to migrate to the surface rapidly after film removal, prior to mesostructure formation. X-ray reflectivity indicates that films formed at different PEI:CTAB compositions retain mesophase regular structures with the same d-spacing feature, equal to 52.2 Å. Grazing incidence diffraction measurements indicate that films are composed of small crystallites arranged in a random powder fashion, developing a rough surface morphology evidenced by BAM. The central finding is that PEI:CTAB films form when the amount of CTAB in solution is higher than a critical film formation concentration, very close to the critical aggregation concentration (CAC), allowing the formation of several equilibrated films from the same growing solution.</p>}},
author = {{Comas-Rojas, H. and Fernández-Catá, G. and Edler, K. J. and Roser, S. J. and Pérez-Gramatges, A.}},
issn = {{0021-9797}},
keywords = {{CTAB; PEI; Potentiometry; Reflectometry; Surfactant; Thin films}},
language = {{eng}},
month = {{11}},
number = {{2}},
pages = {{495--501}},
publisher = {{Elsevier}},
series = {{Journal of Colloid and Interface Science}},
title = {{Multiple thin film formation from dilute mixtures of polyethyleneimine (PEI) and cetyltrimethylammonium bromide (CTAB)}},
url = {{http://dx.doi.org/10.1016/j.jcis.2009.07.067}},
doi = {{10.1016/j.jcis.2009.07.067}},
volume = {{339}},
year = {{2009}},
}