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Interactions of Small Dendrimers with Sodium Dodecyl Sulfate at the Air-Water Interface.

Yanez, Marianna LU ; Campbell, Richard A; Watkins, Erik B; Obiols-Rabasa, Marc LU ; Schillén, Karin LU and Nylander, Tommy LU (2014) In The Journal of Physical Chemistry Part B 118(40). p.11835-11848
Abstract
We have determined how the bulk behavior of mixtures of small cationic poly(amidoamine) dendrimers (generation 2, PAMAM-G2) and sodium dodecyl sulfate (SDS) affects the structure and composition of the adsorbed layers at the air-water interface. The aim is to reveal how the size of a well-defined hyperbranched polyelectrolyte affects the interfacial and bulk solution behavior of mixtures with oppositely charged surfactants, when the size of the polyelectrolyte approaches that of the surfactant. A combination of electrophoretic mobility, UV-vis spectroscopy, dynamic light scattering, and small-angle X-ray scattering measurements have been employed to characterize the interactions in the bulk solution. PAMAM-G2 associates strongly with SDS... (More)
We have determined how the bulk behavior of mixtures of small cationic poly(amidoamine) dendrimers (generation 2, PAMAM-G2) and sodium dodecyl sulfate (SDS) affects the structure and composition of the adsorbed layers at the air-water interface. The aim is to reveal how the size of a well-defined hyperbranched polyelectrolyte affects the interfacial and bulk solution behavior of mixtures with oppositely charged surfactants, when the size of the polyelectrolyte approaches that of the surfactant. A combination of electrophoretic mobility, UV-vis spectroscopy, dynamic light scattering, and small-angle X-ray scattering measurements have been employed to characterize the interactions in the bulk solution. PAMAM-G2 associates strongly with SDS in the bulk, forming large aggregates where the size and the charge depend on the bulk composition. We show that kinetically trapped aggregates can be formed at compositions outside the equilibrium two-phase region, and the positively charged aggregates are larger than the negative ones. Surface tensiometry, neutron reflectometry, and ellipsometry have been used to reveal the properties of the interfacial layers. The interfacial structures formed depend strongly on the bulk composition: structured layers are present for samples inside the two-phase region, whereas intact nanostructured aggregates adsorb for samples just outside the two-phase region. The interfacial behavior of PAMAM-G2/SDS mixtures is compared with that of small amines or multivalent ions and oppositely charged surfactants. The implications of aggregate adsorption, dissociation, and spreading processes are discussed as well as the potential of small dendrimers for applications involving the delivery of functional molecules to interfaces. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
The Journal of Physical Chemistry Part B
volume
118
issue
40
pages
11835 - 11848
publisher
The American Chemical Society
external identifiers
  • pmid:25203770
  • wos:000343016000025
  • scopus:84907889371
ISSN
1520-5207
DOI
10.1021/jp507230m
language
English
LU publication?
yes
id
c32ef422-531e-4884-a4fc-2612f3099f9c (old id 4691968)
date added to LUP
2014-10-07 16:49:55
date last changed
2017-10-01 03:23:24
@article{c32ef422-531e-4884-a4fc-2612f3099f9c,
  abstract     = {We have determined how the bulk behavior of mixtures of small cationic poly(amidoamine) dendrimers (generation 2, PAMAM-G2) and sodium dodecyl sulfate (SDS) affects the structure and composition of the adsorbed layers at the air-water interface. The aim is to reveal how the size of a well-defined hyperbranched polyelectrolyte affects the interfacial and bulk solution behavior of mixtures with oppositely charged surfactants, when the size of the polyelectrolyte approaches that of the surfactant. A combination of electrophoretic mobility, UV-vis spectroscopy, dynamic light scattering, and small-angle X-ray scattering measurements have been employed to characterize the interactions in the bulk solution. PAMAM-G2 associates strongly with SDS in the bulk, forming large aggregates where the size and the charge depend on the bulk composition. We show that kinetically trapped aggregates can be formed at compositions outside the equilibrium two-phase region, and the positively charged aggregates are larger than the negative ones. Surface tensiometry, neutron reflectometry, and ellipsometry have been used to reveal the properties of the interfacial layers. The interfacial structures formed depend strongly on the bulk composition: structured layers are present for samples inside the two-phase region, whereas intact nanostructured aggregates adsorb for samples just outside the two-phase region. The interfacial behavior of PAMAM-G2/SDS mixtures is compared with that of small amines or multivalent ions and oppositely charged surfactants. The implications of aggregate adsorption, dissociation, and spreading processes are discussed as well as the potential of small dendrimers for applications involving the delivery of functional molecules to interfaces.},
  author       = {Yanez, Marianna and Campbell, Richard A and Watkins, Erik B and Obiols-Rabasa, Marc and Schillén, Karin and Nylander, Tommy},
  issn         = {1520-5207},
  language     = {eng},
  number       = {40},
  pages        = {11835--11848},
  publisher    = {The American Chemical Society},
  series       = {The Journal of Physical Chemistry Part B},
  title        = {Interactions of Small Dendrimers with Sodium Dodecyl Sulfate at the Air-Water Interface.},
  url          = {http://dx.doi.org/10.1021/jp507230m},
  volume       = {118},
  year         = {2014},
}