Eur. Phys. J. E (2008) 26: 35-41
https://doi.org/10.1140/epje/i2007-10322-1

ISMC-2007

Observation of slow down of polystyrene nanogels diffusivities in contact with swollen polystyrene brushes

¹ FORTH, Institute of Electronic Structure and Laser, Heraklion, Greece
² Department of Microsystems Engineering, IMTEK, University of Freiburg, Freiburg, Germany
³ Department of Materials Science and Technology, University of Crete, Heraklion, Greece
⁴ Max Plank Institute for Colloid and Interface Science, Golm, Germany

^* e-mail: benoit@iesl.forth.gr

Received: 9 November 2007
Accepted: 9 April 2008
Published online: 13 May 2008

Abstract

The diffusion of dilute colloids in contact with swollen polymer brushes has been studied by evanescent wave dynamic light scattering. Two polystyrene nanogels with 16nm and 42nm radius were put into contact with three polystyrene brushes with varying grafting densities. Partial penetration of the nanogels within the brushes was revealed by the evanescent wave penetration depth-dependent scattering intensities. The experimental short-time diffusion coefficients of the penetrating particles were measured and found to strongly slow down as the nanoparticles get deeper into the brushes. The slow down is much more marked for the smaller (16nm) nanogels, suggesting a size exclusion type of mechanism and the existence of a characteristic length scale present in the outer part of the brush.