Résumé
Radical addition of ω-iodofluorinated telomers was used to modify silica (S50) nanoparticles bearing vinyl groups. These iodo terminated derivatives were either commercially available tetrafluoroethylene telomers, CnF2n+1I with n = 4 or 6, or vinylidene fluoride telomers, CnF2n+1[VDF]mI with m = 6 and 23. These latters were synthesized by radical telomerization of VDF with CnF2n+1I initiated by bis(4-tertbutylcyclohexyl) peroxydicarbonate in high yields (>85%). The resulting nanohybrids were characterized by solid state NMR spectroscopy, elemental analyses and thermogravimetry. A covalent grafting between double bonds and fluorinated iodotelomers was noted. The covering density of fluorinated chains was assessed and reported with respect to fluorinated chain lengths. These nanohybrids exhibited a high thermostability (higher than 400 °C under air), losing less than 10% by weight at 700 °C, and a low surface tension, γs, from around 15 mN/m to about 44 mN/m for silica.