Controlled structure and density of “living” polystyrene brushes on flat silica surfaces C. Devaux, J.P. Chapel, E. Beyou and Ph. Chaumont Eur. Phys. J. E, 7 4 (2002) 345-352 Published online: 15 April 2002 DOI: 10.1140/epje/i2001-10098-2