Novel evaluation method of neutron reflectivity data applied to stimulus-responsive polymer brushes
(2008) In Soft Matter 4(3). p.500-509- Abstract
- Neutron reflectivity (NR) measurements have been performed on stimulus-responsive polymer brushes containing N-isopropylacrylamide (NIPAAM) at different temperatures and contrasts using two different brush samples of roughly the same grafting density and layer thickness. The NR data were analyzed using a novel method employing polymer density profiles predicted from lattice mean-field theory augmented with a polymer model to describe polymer solubility that decreases with increasing temperature. The predicted density profiles at the different temperatures were self-consistent with the experimentally observed profiles; hence the experimental data lend credibility to the theory. We found that the brush thickness decreased from 220 to 160 nm... (More)
- Neutron reflectivity (NR) measurements have been performed on stimulus-responsive polymer brushes containing N-isopropylacrylamide (NIPAAM) at different temperatures and contrasts using two different brush samples of roughly the same grafting density and layer thickness. The NR data were analyzed using a novel method employing polymer density profiles predicted from lattice mean-field theory augmented with a polymer model to describe polymer solubility that decreases with increasing temperature. The predicted density profiles at the different temperatures were self-consistent with the experimentally observed profiles; hence the experimental data lend credibility to the theory. We found that the brush thickness decreased from 220 to 160 nm and the polymer volume fraction increased from 55 to 75% when increasing temperature from 293 to 328 K. The new evaluation approach involved significantly fewer independent fitting parameters than methods involving layers of uniform densities. Furthermore, the approach can straightforwardly be extended to analyze neutron reflectivity data of grafted, weakly charged polymers that display pH-sensitive behaviour and also to block copolymers and to surfaces with adsorbed polymers. We propose that such accurate model calculations provide a tool to interpret results from NR experiments more effectively and design neutron reflectivity experiments for optimal outcome. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1193713
- author
- Zhang, Jianming ; Nylander, Tommy LU ; Campbell, Richard LU ; Rennie, Adrian R ; Zauscher, Stefan and Linse, Per LU
- organization
- publishing date
- 2008
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Soft Matter
- volume
- 4
- issue
- 3
- pages
- 500 - 509
- publisher
- Royal Society of Chemistry
- external identifiers
-
- wos:000253492400016
- scopus:39749129626
- ISSN
- 1744-6848
- DOI
- 10.1039/b714911e
- language
- English
- LU publication?
- yes
- id
- 2a1c977e-dd7b-4687-b4ca-139122808db8 (old id 1193713)
- date added to LUP
- 2016-04-01 14:18:25
- date last changed
- 2022-01-27 23:56:29
@article{2a1c977e-dd7b-4687-b4ca-139122808db8,
abstract = {{Neutron reflectivity (NR) measurements have been performed on stimulus-responsive polymer brushes containing N-isopropylacrylamide (NIPAAM) at different temperatures and contrasts using two different brush samples of roughly the same grafting density and layer thickness. The NR data were analyzed using a novel method employing polymer density profiles predicted from lattice mean-field theory augmented with a polymer model to describe polymer solubility that decreases with increasing temperature. The predicted density profiles at the different temperatures were self-consistent with the experimentally observed profiles; hence the experimental data lend credibility to the theory. We found that the brush thickness decreased from 220 to 160 nm and the polymer volume fraction increased from 55 to 75% when increasing temperature from 293 to 328 K. The new evaluation approach involved significantly fewer independent fitting parameters than methods involving layers of uniform densities. Furthermore, the approach can straightforwardly be extended to analyze neutron reflectivity data of grafted, weakly charged polymers that display pH-sensitive behaviour and also to block copolymers and to surfaces with adsorbed polymers. We propose that such accurate model calculations provide a tool to interpret results from NR experiments more effectively and design neutron reflectivity experiments for optimal outcome.}},
author = {{Zhang, Jianming and Nylander, Tommy and Campbell, Richard and Rennie, Adrian R and Zauscher, Stefan and Linse, Per}},
issn = {{1744-6848}},
language = {{eng}},
number = {{3}},
pages = {{500--509}},
publisher = {{Royal Society of Chemistry}},
series = {{Soft Matter}},
title = {{Novel evaluation method of neutron reflectivity data applied to stimulus-responsive polymer brushes}},
url = {{http://dx.doi.org/10.1039/b714911e}},
doi = {{10.1039/b714911e}},
volume = {{4}},
year = {{2008}},
}