Advanced

Adsorption of Branched-Linear Polyethyleneimine-Ethylene Oxide Conjugate on Hydrophilic Silica Investigated by Ellipsometry and Monte Carlo Simulations

Angelescu, Daniel LU ; Nylander, Tommy LU ; Piculell, Lennart LU ; Linse, Per LU ; Lindman, Björn LU ; Tropsch, Juergen and Detering, Juergen (2011) In Langmuir 27(16). p.9961-9971
Abstract
The adsorption of and conformation adopted by a branched-linear polymer conjugate to the hydrophilic silica aqueous solution interface have been studied by in situ null ellipsornetry and Monte Carlo simulations. The conjugate is a highly branched polyethyleneimine structure with ethyleneoxide chains grafted to its primary and secondary amino groups. In situ null ellipsometry demonstrated that the polymer conjugate adsorbs to the silica surface from water and aqueous solution of 1 mM asymmetric divalent salt (calcium and magnesium chloride to emulate hard water) over a large pH range. The adsorbed amount is hardly affected by pH and large charge reversal on the negatively charged silica surface occurred at pH = 4.0, due to the adsorption of... (More)
The adsorption of and conformation adopted by a branched-linear polymer conjugate to the hydrophilic silica aqueous solution interface have been studied by in situ null ellipsornetry and Monte Carlo simulations. The conjugate is a highly branched polyethyleneimine structure with ethyleneoxide chains grafted to its primary and secondary amino groups. In situ null ellipsometry demonstrated that the polymer conjugate adsorbs to the silica surface from water and aqueous solution of 1 mM asymmetric divalent salt (calcium and magnesium chloride to emulate hard water) over a large pH range. The adsorbed amount is hardly affected by pH and large charge reversal on the negatively charged silica surface occurred at pH = 4.0, due to the adsorption of the cationic polyelectrolyte. The Monte Carlo simulations using an appropriate coarse-grained model of the polymer in solution predicted a core shell structure with no sharp boundary between the ethyleneimine and ethyleneoxide moieties. The structure at the interface is similar to that in solution when the polymer degree of protonation is low or moderate while at high degree of protonation the strong electrostatic attraction between the ethyleneimine core and oppositely charged silica surface distorts the ethyleneoxide shell so that an "anemone"-like configuration is adopted. The adsorption of alkyl benzene sulfonic acid (LAS) to a preadsorbed polymer layer was also investigated by null ellipsometry. The adsorption data brought additional support for the existence of a strong polymer adsorption and showed the presence of a binding which was further enhanced by the decreased solvency of the surfactant in the salt solution and confirmed the surface charge reversal by the polymer adsorption at pH = 4.0. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Langmuir
volume
27
issue
16
pages
9961 - 9971
publisher
The American Chemical Society
external identifiers
  • wos:000293662800040
  • scopus:80051483344
ISSN
0743-7463
DOI
10.1021/la2017209
language
English
LU publication?
yes
id
e3f5260d-64f7-46c2-ae6a-9d5329f89a81 (old id 2159232)
date added to LUP
2011-09-22 15:50:45
date last changed
2017-01-01 04:09:53
@article{e3f5260d-64f7-46c2-ae6a-9d5329f89a81,
  abstract     = {The adsorption of and conformation adopted by a branched-linear polymer conjugate to the hydrophilic silica aqueous solution interface have been studied by in situ null ellipsornetry and Monte Carlo simulations. The conjugate is a highly branched polyethyleneimine structure with ethyleneoxide chains grafted to its primary and secondary amino groups. In situ null ellipsometry demonstrated that the polymer conjugate adsorbs to the silica surface from water and aqueous solution of 1 mM asymmetric divalent salt (calcium and magnesium chloride to emulate hard water) over a large pH range. The adsorbed amount is hardly affected by pH and large charge reversal on the negatively charged silica surface occurred at pH = 4.0, due to the adsorption of the cationic polyelectrolyte. The Monte Carlo simulations using an appropriate coarse-grained model of the polymer in solution predicted a core shell structure with no sharp boundary between the ethyleneimine and ethyleneoxide moieties. The structure at the interface is similar to that in solution when the polymer degree of protonation is low or moderate while at high degree of protonation the strong electrostatic attraction between the ethyleneimine core and oppositely charged silica surface distorts the ethyleneoxide shell so that an "anemone"-like configuration is adopted. The adsorption of alkyl benzene sulfonic acid (LAS) to a preadsorbed polymer layer was also investigated by null ellipsometry. The adsorption data brought additional support for the existence of a strong polymer adsorption and showed the presence of a binding which was further enhanced by the decreased solvency of the surfactant in the salt solution and confirmed the surface charge reversal by the polymer adsorption at pH = 4.0.},
  author       = {Angelescu, Daniel and Nylander, Tommy and Piculell, Lennart and Linse, Per and Lindman, Björn and Tropsch, Juergen and Detering, Juergen},
  issn         = {0743-7463},
  language     = {eng},
  number       = {16},
  pages        = {9961--9971},
  publisher    = {The American Chemical Society},
  series       = {Langmuir},
  title        = {Adsorption of Branched-Linear Polyethyleneimine-Ethylene Oxide Conjugate on Hydrophilic Silica Investigated by Ellipsometry and Monte Carlo Simulations},
  url          = {http://dx.doi.org/10.1021/la2017209},
  volume       = {27},
  year         = {2011},
}