Jump to main content
Jump to site search

Issue 3, 2008
Previous Article Next Article

Novel evaluation method of neutron reflectivity data applied to stimulus-responsive polymer brushes

Author affiliations

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.

Graphical abstract: Novel evaluation method of neutron reflectivity data applied to stimulus-responsive polymer brushes

Back to tab navigation
Please wait while Download options loads

Publication details

The article was received on 27 Sep 2007, accepted on 10 Dec 2007 and first published on 08 Jan 2008


Article type: Paper
DOI: 10.1039/B714911E
Citation: Soft Matter, 2008,4, 500-509
  •   Request permissions

    Novel evaluation method of neutron reflectivity data applied to stimulus-responsive polymer brushes

    J. Zhang, T. Nylander, R. A. Campbell, A. R. Rennie, S. Zauscher and P. Linse, Soft Matter, 2008, 4, 500
    DOI: 10.1039/B714911E

Search articles by author