Abstract
Adsorption of iminium ion end-functionalized polystyrene on model rough surfaces has been investigated. The model surfaces were prepared by spin coating a solution of colloidal silica beads on aluminumcoated silicon surfaces. Atomic force microscopy and scanning electron microscopy of the surfaces revealed a nearly hexagonal packing of beads. Static secondary ion mass spectroscopy and X-ray photoelectron spectroscopy have been used to measure relative changes in the adsorbed amounts on the model surfaces compared to a flat surface. We observe a significant enhancement of adsorption when the bead to polymer radius (ρ/Rg) is of order unity. For ρ/Rg ≫1, the adsorbed amounts approach that on the smooth surfaces, whereas for ρ/Rg< 1, the adsorption is substantially reduced. The enhancement in adsorption is interpreted as a favorable reduction in crowding or stretching energy on adsorption, whereas the reduction is understood in terms of topologically induced steric hindrance to adsorption.
Original language | English (US) |
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Pages (from-to) | 2586-2594 |
Number of pages | 9 |
Journal | Macromolecules |
Volume | 27 |
Issue number | 9 |
DOIs | |
State | Published - Apr 1 1994 |