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Investigation of Thermoresponsive Nano‐Confined Polymer Brushes by AFM‐Based Force Spectroscopy
Author(s) -
Radji Sadia,
Alem Halima,
DemoustierChampagne Sophie,
Jonas Alain M.,
Cuenot Stéphane
Publication year - 2012
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.201100636
Subject(s) - polymer , force spectroscopy , materials science , grafting , polymer chemistry , atomic force microscopy , nano , nanopore , polymerization , membrane , chemical engineering , nanotechnology , composite material , chemistry , biochemistry , engineering
PNIPAM polymer brushes are synthesized in nanopores of track‐etched membranes. The internal structure of these nano‐confined brushes is studied by AFM force spectroscopy experiments as a function of the synthesis conditions. The approach force vs. distance profiles are fitted using the Alexander‐de Gennes model to determine the grafting density, and the worm‐like chain model is used to estimate the chain length from the retract profiles. The grafting density for brushes synthesized within 80 nm pores is ten times lower than that obtained in 330 nm pores. For the same polymerization time, the chain lengths are much lower if the synthesis is carried out in small pores. The elastic properties of the brushes are also directly related to the confinement conditions.