Eur. Phys. J. E 7, 345-352 (2002)
DOI: 10.1140/epje/i2001-10098-2
Controlled structure and density of "living" polystyrene brushes on flat silica surfaces
C. Devaux, J.P. Chapel, E. Beyou and Ph. ChaumontLaboratoire des Matériaux Polymères et Biomatériaux - UMR CNRS 5627, Blg. ISTIL Université Claude Bernard Lyon I, 43, bd. du 11 novembre 1918, 69622 Villeurbanne Cedex, France chapel@matplast.univ-lyon1.fr
(Received 20 December 2001)
Abstract
Thin layers of polystyrene were grown from surface-grafted nitroxide
initiators via controlled "living" free radical polymerization. The
"reactive" Langmuir-Blodgett deposition method allowed an effective
control of the initiator layer density leading to PS brushes with different
and high grafting density and stretching. The influence of the grafting
density on the layer structure was studied. Comparison with theoretical
predictions for monodispersed brushes in bad solvent was discussed. The
thickness was found to vary linearly with molecular weight and the density
dependence was shown using wetting measurements. Special features of
controlled radical nitroxide polymerization from a surface were discussed. A
direct comparison of the molecular weight and polydispersity between surface
and bulk polymers was made by de-grafting the brushes into a toluene/HF
solution. Finally, some evidence of a "surface Fischer" effect was shown
from re-initiated layers.
68.47.Mn - Polymer surfaces.
82.35.-x - Polymers: properties; reactions; polymerization.
82.65.+r - Surface and interface chemistry; heterogeneous catalysis at surfaces.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2002
