Effect of grafting density on phase transition behavior for poly(N-isopropylacryamide) brushes in aqueous solutions studied by AFM and QCM-D

Ishida, Naoyuki and Biggs, Simon (2010) Effect of grafting density on phase transition behavior for poly(N-isopropylacryamide) brushes in aqueous solutions studied by AFM and QCM-D. Macromolecules, 43 17: 7269-7276. doi:10.1021/ma101113g


Author Ishida, Naoyuki
Biggs, Simon
Title Effect of grafting density on phase transition behavior for poly(N-isopropylacryamide) brushes in aqueous solutions studied by AFM and QCM-D
Journal name Macromolecules   Check publisher's open access policy
ISSN 0024-9297
1520-5835
Publication date 2010-09-14
Sub-type Article (original research)
DOI 10.1021/ma101113g
Volume 43
Issue 17
Start page 7269
End page 7276
Total pages 8
Place of publication Washington, DC, United States
Publisher American Chemical Society
Language eng
Abstract The effect of grafting density on the phase transition behavior of poly(N-isopropylacrylamide) (PNIPAM) grafted onto a flat substrate was investigated using an atomic force microscope (AFM) and a quartz crystal microbalance (QCM-D). We prepared PNIPAM brush layers at three different grafting densities on silicon wafers using a "grafting from" atom transfer radical polymerization (ATRP) approach. AFM imaging in water at various temperatures showed that the transition behavior of the grafted PNIPAM chains from a brush-like to a mushroom-like morphology was dependent on the grafting density: the images change abruptly from essentially featureless to domain structures across the LCST for the low-density surface, whereas the change in the images becomes less abrupt with increasing polymer graft density. The QCM-D data also indicated a significant dependence of the layer properties on the grafting density, confirming the behavior differences suggested by the AFM images. In particular, the dissipation data strongly suggest that the magnitude of lateral aggregation for the PNIPAM chains depends on the grafting density. A similar effect of grafting density was also observed for the phase transition as a function of salt concentration in sodium sulfate solutions.
Keyword Washington, DC, United States
American Chemical Society
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: Faculty of Engineering, Architecture and Information Technology Publications
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 51 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 51 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Sat, 14 Jun 2014, 06:16:56 EST by System User on behalf of Faculty Of Engineering, Architecture & Info Tech