Eur. Phys. J. E 7, 345-352 (2002)
Controlled structure and density of "living" polystyrene brushes on flat silica surfacesC. Devaux, J.P. Chapel, E. Beyou and Ph. Chaumont
Laboratoire 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 email@example.com
(Received 20 December 2001)
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