Association of a hydrophobically modified polyelectrolyte and a block copolymer followed by fluorescence techniques
Costa, Telma LU ; Schillén, Karin LU
; Miguel, Maria
LU
; Lindman, Björn
LU
and Seixas de Melo, J. Sergio
(2009)
In The Journal of Physical Chemistry Part B
113(18).
p.6194-6204
- Abstract
- By using absorption and fluorescence (steady-state and time-resolved) techniques the
interaction between a poly(acrylic acid) PAA, randomly grafted with pyrene (Py) units
(PAAMePy55) and a triblock copolymer of poly(ethylene oxide) and poly(propylene
oxide) (EO20PO68EO20, P123) was investigated. From the fluorescence data it is shown
that upon addition of P123 a decrease of the (pyrene-pyrene, Py-Py) intramolecular
association, i.e., a decrease of dynamic and static excimer formation, is observed. Timeresolved
fluorescence data reveal the existence of two types of monomers (monomers
that are able to form excimer, MAGRE, and isolated monomers) and two excimers.
Addition... (More) - By using absorption and fluorescence (steady-state and time-resolved) techniques the
interaction between a poly(acrylic acid) PAA, randomly grafted with pyrene (Py) units
(PAAMePy55) and a triblock copolymer of poly(ethylene oxide) and poly(propylene
oxide) (EO20PO68EO20, P123) was investigated. From the fluorescence data it is shown
that upon addition of P123 a decrease of the (pyrene-pyrene, Py-Py) intramolecular
association, i.e., a decrease of dynamic and static excimer formation, is observed. Timeresolved
fluorescence data reveal the existence of two types of monomers (monomers
that are able to form excimer, MAGRE, and isolated monomers) and two excimers.
Addition of P123 causes also an increase of the amount of isolated Py monomers. The
overall fluorescence data suggest that the PAAMePy55 and the P123 block copolymer
associate strongly at low pH, leading to the formation of P123 micelles surrounded by
one PAAMePy55 chain, where the pyrene groups are located at the PPO/PEO interface
of the P123 micelles. Steady-state fluorescence results also showed that an excess of
P123 micelles in solution is required for the association to occur. At high pH (pH 9 and
above), the situation is less clear, the steady-state (particularly in the I1/I3 ratio) and
time-resolved fluorescence results indicate a contact between the pyrene groups and
PEO, which then would imply that there may be an interaction, but much weaker than at
low pH. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1291751
- author
- Costa, Telma
LU
; Schillén, Karin
LU
; Miguel, Maria
LU
; Lindman, Björn
LU
and Seixas de Melo, J. Sergio
- organization
- publishing date
- 2009
- type
- Contribution to journal
- publication status
- published
- subject
- in
- The Journal of Physical Chemistry Part B
- volume
- 113
- issue
- 18
- pages
- 6194 - 6204
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- pmid:19354273
- wos:000265687500004
- scopus:66349109972
- pmid:19354273
- ISSN
- 1520-5207
- DOI
- 10.1021/jp8093879
- language
- English
- LU publication?
- yes
- id
- bbed9123-0620-4f0c-95f3-9afd85113394 (old id 1291751)
- date added to LUP
- 2016-04-01 14:50:46
- date last changed
- 2025-04-04 14:13:57
@article{bbed9123-0620-4f0c-95f3-9afd85113394,
abstract = {{By using absorption and fluorescence (steady-state and time-resolved) techniques the<br/><br>
interaction between a poly(acrylic acid) PAA, randomly grafted with pyrene (Py) units<br/><br>
(PAAMePy55) and a triblock copolymer of poly(ethylene oxide) and poly(propylene<br/><br>
oxide) (EO20PO68EO20, P123) was investigated. From the fluorescence data it is shown<br/><br>
that upon addition of P123 a decrease of the (pyrene-pyrene, Py-Py) intramolecular<br/><br>
association, i.e., a decrease of dynamic and static excimer formation, is observed. Timeresolved<br/><br>
fluorescence data reveal the existence of two types of monomers (monomers<br/><br>
that are able to form excimer, MAGRE, and isolated monomers) and two excimers.<br/><br>
Addition of P123 causes also an increase of the amount of isolated Py monomers. The<br/><br>
overall fluorescence data suggest that the PAAMePy55 and the P123 block copolymer<br/><br>
associate strongly at low pH, leading to the formation of P123 micelles surrounded by<br/><br>
one PAAMePy55 chain, where the pyrene groups are located at the PPO/PEO interface<br/><br>
of the P123 micelles. Steady-state fluorescence results also showed that an excess of<br/><br>
P123 micelles in solution is required for the association to occur. At high pH (pH 9 and<br/><br>
above), the situation is less clear, the steady-state (particularly in the I1/I3 ratio) and<br/><br>
time-resolved fluorescence results indicate a contact between the pyrene groups and<br/><br>
PEO, which then would imply that there may be an interaction, but much weaker than at<br/><br>
low pH.}},
author = {{Costa, Telma and Schillén, Karin and Miguel, Maria and Lindman, Björn and Seixas de Melo, J. Sergio}},
issn = {{1520-5207}},
language = {{eng}},
number = {{18}},
pages = {{6194--6204}},
publisher = {{The American Chemical Society (ACS)}},
series = {{The Journal of Physical Chemistry Part B}},
title = {{Association of a hydrophobically modified polyelectrolyte and a block copolymer followed by fluorescence techniques}},
url = {{http://dx.doi.org/10.1021/jp8093879}},
doi = {{10.1021/jp8093879}},
volume = {{113}},
year = {{2009}},
}